License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 08:07:57 -06:00
|
|
|
// SPDX-License-Identifier: GPL-2.0
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
#include "audit.h"
|
2009-12-17 18:12:05 -07:00
|
|
|
#include <linux/fsnotify_backend.h>
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
#include <linux/namei.h>
|
|
|
|
#include <linux/mount.h>
|
2009-06-23 22:02:38 -06:00
|
|
|
#include <linux/kthread.h>
|
2017-05-02 08:16:04 -06:00
|
|
|
#include <linux/refcount.h>
|
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 02:04:11 -06:00
|
|
|
#include <linux/slab.h>
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
|
|
|
|
struct audit_tree;
|
|
|
|
struct audit_chunk;
|
|
|
|
|
|
|
|
struct audit_tree {
|
2017-05-02 08:16:04 -06:00
|
|
|
refcount_t count;
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
int goner;
|
|
|
|
struct audit_chunk *root;
|
|
|
|
struct list_head chunks;
|
|
|
|
struct list_head rules;
|
|
|
|
struct list_head list;
|
|
|
|
struct list_head same_root;
|
|
|
|
struct rcu_head head;
|
|
|
|
char pathname[];
|
|
|
|
};
|
|
|
|
|
|
|
|
struct audit_chunk {
|
|
|
|
struct list_head hash;
|
2009-12-17 19:24:24 -07:00
|
|
|
struct fsnotify_mark mark;
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
struct list_head trees; /* with root here */
|
|
|
|
int dead;
|
|
|
|
int count;
|
Fix inotify watch removal/umount races
Inotify watch removals suck violently.
To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex. That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount. We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.
Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done. Cleanup is just deactivate_super().
However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords. That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.
We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable. OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e. that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().
So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong. We had
to drop ih->mutex before we could grab ->s_umount. So the watch
could've been gone already.
That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer. If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address. That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that. Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.
So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check. If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.
And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-14 18:15:43 -07:00
|
|
|
atomic_long_t refs;
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
struct rcu_head head;
|
|
|
|
struct node {
|
|
|
|
struct list_head list;
|
|
|
|
struct audit_tree *owner;
|
|
|
|
unsigned index; /* index; upper bit indicates 'will prune' */
|
|
|
|
} owners[];
|
|
|
|
};
|
|
|
|
|
|
|
|
static LIST_HEAD(tree_list);
|
|
|
|
static LIST_HEAD(prune_list);
|
2015-02-23 13:37:59 -07:00
|
|
|
static struct task_struct *prune_thread;
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
|
|
|
|
/*
|
|
|
|
* One struct chunk is attached to each inode of interest.
|
|
|
|
* We replace struct chunk on tagging/untagging.
|
|
|
|
* Rules have pointer to struct audit_tree.
|
|
|
|
* Rules have struct list_head rlist forming a list of rules over
|
|
|
|
* the same tree.
|
|
|
|
* References to struct chunk are collected at audit_inode{,_child}()
|
|
|
|
* time and used in AUDIT_TREE rule matching.
|
|
|
|
* These references are dropped at the same time we are calling
|
|
|
|
* audit_free_names(), etc.
|
|
|
|
*
|
|
|
|
* Cyclic lists galore:
|
|
|
|
* tree.chunks anchors chunk.owners[].list hash_lock
|
|
|
|
* tree.rules anchors rule.rlist audit_filter_mutex
|
|
|
|
* chunk.trees anchors tree.same_root hash_lock
|
|
|
|
* chunk.hash is a hash with middle bits of watch.inode as
|
|
|
|
* a hash function. RCU, hash_lock
|
|
|
|
*
|
|
|
|
* tree is refcounted; one reference for "some rules on rules_list refer to
|
|
|
|
* it", one for each chunk with pointer to it.
|
|
|
|
*
|
2009-12-17 18:12:05 -07:00
|
|
|
* chunk is refcounted by embedded fsnotify_mark + .refs (non-zero refcount
|
Fix inotify watch removal/umount races
Inotify watch removals suck violently.
To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex. That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount. We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.
Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done. Cleanup is just deactivate_super().
However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords. That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.
We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable. OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e. that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().
So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong. We had
to drop ih->mutex before we could grab ->s_umount. So the watch
could've been gone already.
That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer. If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address. That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that. Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.
So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check. If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.
And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-14 18:15:43 -07:00
|
|
|
* of watch contributes 1 to .refs).
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
*
|
|
|
|
* node.index allows to get from node.list to containing chunk.
|
|
|
|
* MSB of that sucker is stolen to mark taggings that we might have to
|
|
|
|
* revert - several operations have very unpleasant cleanup logics and
|
|
|
|
* that makes a difference. Some.
|
|
|
|
*/
|
|
|
|
|
2009-12-17 18:12:05 -07:00
|
|
|
static struct fsnotify_group *audit_tree_group;
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
|
|
|
|
static struct audit_tree *alloc_tree(const char *s)
|
|
|
|
{
|
|
|
|
struct audit_tree *tree;
|
|
|
|
|
|
|
|
tree = kmalloc(sizeof(struct audit_tree) + strlen(s) + 1, GFP_KERNEL);
|
|
|
|
if (tree) {
|
2017-05-02 08:16:04 -06:00
|
|
|
refcount_set(&tree->count, 1);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
tree->goner = 0;
|
|
|
|
INIT_LIST_HEAD(&tree->chunks);
|
|
|
|
INIT_LIST_HEAD(&tree->rules);
|
|
|
|
INIT_LIST_HEAD(&tree->list);
|
|
|
|
INIT_LIST_HEAD(&tree->same_root);
|
|
|
|
tree->root = NULL;
|
|
|
|
strcpy(tree->pathname, s);
|
|
|
|
}
|
|
|
|
return tree;
|
|
|
|
}
|
|
|
|
|
|
|
|
static inline void get_tree(struct audit_tree *tree)
|
|
|
|
{
|
2017-05-02 08:16:04 -06:00
|
|
|
refcount_inc(&tree->count);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
static inline void put_tree(struct audit_tree *tree)
|
|
|
|
{
|
2017-05-02 08:16:04 -06:00
|
|
|
if (refcount_dec_and_test(&tree->count))
|
2011-03-15 04:03:53 -06:00
|
|
|
kfree_rcu(tree, head);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
/* to avoid bringing the entire thing in audit.h */
|
|
|
|
const char *audit_tree_path(struct audit_tree *tree)
|
|
|
|
{
|
|
|
|
return tree->pathname;
|
|
|
|
}
|
|
|
|
|
Fix inotify watch removal/umount races
Inotify watch removals suck violently.
To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex. That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount. We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.
Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done. Cleanup is just deactivate_super().
However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords. That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.
We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable. OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e. that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().
So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong. We had
to drop ih->mutex before we could grab ->s_umount. So the watch
could've been gone already.
That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer. If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address. That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that. Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.
So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check. If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.
And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-14 18:15:43 -07:00
|
|
|
static void free_chunk(struct audit_chunk *chunk)
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
{
|
|
|
|
int i;
|
|
|
|
|
|
|
|
for (i = 0; i < chunk->count; i++) {
|
|
|
|
if (chunk->owners[i].owner)
|
|
|
|
put_tree(chunk->owners[i].owner);
|
|
|
|
}
|
|
|
|
kfree(chunk);
|
|
|
|
}
|
|
|
|
|
Fix inotify watch removal/umount races
Inotify watch removals suck violently.
To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex. That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount. We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.
Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done. Cleanup is just deactivate_super().
However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords. That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.
We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable. OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e. that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().
So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong. We had
to drop ih->mutex before we could grab ->s_umount. So the watch
could've been gone already.
That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer. If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address. That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that. Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.
So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check. If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.
And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-14 18:15:43 -07:00
|
|
|
void audit_put_chunk(struct audit_chunk *chunk)
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
{
|
Fix inotify watch removal/umount races
Inotify watch removals suck violently.
To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex. That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount. We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.
Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done. Cleanup is just deactivate_super().
However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords. That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.
We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable. OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e. that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().
So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong. We had
to drop ih->mutex before we could grab ->s_umount. So the watch
could've been gone already.
That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer. If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address. That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that. Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.
So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check. If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.
And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-14 18:15:43 -07:00
|
|
|
if (atomic_long_dec_and_test(&chunk->refs))
|
|
|
|
free_chunk(chunk);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
}
|
|
|
|
|
Fix inotify watch removal/umount races
Inotify watch removals suck violently.
To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex. That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount. We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.
Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done. Cleanup is just deactivate_super().
However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords. That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.
We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable. OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e. that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().
So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong. We had
to drop ih->mutex before we could grab ->s_umount. So the watch
could've been gone already.
That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer. If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address. That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that. Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.
So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check. If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.
And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-14 18:15:43 -07:00
|
|
|
static void __put_chunk(struct rcu_head *rcu)
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
{
|
Fix inotify watch removal/umount races
Inotify watch removals suck violently.
To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex. That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount. We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.
Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done. Cleanup is just deactivate_super().
However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords. That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.
We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable. OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e. that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().
So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong. We had
to drop ih->mutex before we could grab ->s_umount. So the watch
could've been gone already.
That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer. If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address. That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that. Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.
So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check. If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.
And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-14 18:15:43 -07:00
|
|
|
struct audit_chunk *chunk = container_of(rcu, struct audit_chunk, head);
|
|
|
|
audit_put_chunk(chunk);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
}
|
|
|
|
|
2009-12-17 19:24:24 -07:00
|
|
|
static void audit_tree_destroy_watch(struct fsnotify_mark *entry)
|
2009-12-17 18:12:05 -07:00
|
|
|
{
|
|
|
|
struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark);
|
|
|
|
call_rcu(&chunk->head, __put_chunk);
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct audit_chunk *alloc_chunk(int count)
|
|
|
|
{
|
|
|
|
struct audit_chunk *chunk;
|
|
|
|
size_t size;
|
|
|
|
int i;
|
|
|
|
|
|
|
|
size = offsetof(struct audit_chunk, owners) + count * sizeof(struct node);
|
|
|
|
chunk = kzalloc(size, GFP_KERNEL);
|
|
|
|
if (!chunk)
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
INIT_LIST_HEAD(&chunk->hash);
|
|
|
|
INIT_LIST_HEAD(&chunk->trees);
|
|
|
|
chunk->count = count;
|
|
|
|
atomic_long_set(&chunk->refs, 1);
|
|
|
|
for (i = 0; i < count; i++) {
|
|
|
|
INIT_LIST_HEAD(&chunk->owners[i].list);
|
|
|
|
chunk->owners[i].index = i;
|
|
|
|
}
|
2016-12-21 10:06:12 -07:00
|
|
|
fsnotify_init_mark(&chunk->mark, audit_tree_group);
|
2014-11-04 03:27:12 -07:00
|
|
|
chunk->mark.mask = FS_IN_IGNORED;
|
2009-12-17 18:12:05 -07:00
|
|
|
return chunk;
|
|
|
|
}
|
|
|
|
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
enum {HASH_SIZE = 128};
|
|
|
|
static struct list_head chunk_hash_heads[HASH_SIZE];
|
|
|
|
static __cacheline_aligned_in_smp DEFINE_SPINLOCK(hash_lock);
|
|
|
|
|
2016-12-16 02:13:37 -07:00
|
|
|
/* Function to return search key in our hash from inode. */
|
|
|
|
static unsigned long inode_to_key(const struct inode *inode)
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
{
|
2016-12-16 02:13:37 -07:00
|
|
|
return (unsigned long)inode;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Function to return search key in our hash from chunk. Key 0 is special and
|
|
|
|
* should never be present in the hash.
|
|
|
|
*/
|
2016-12-21 04:15:30 -07:00
|
|
|
static unsigned long chunk_to_key(struct audit_chunk *chunk)
|
2017-03-14 07:29:35 -06:00
|
|
|
{
|
2016-12-21 04:15:30 -07:00
|
|
|
/*
|
|
|
|
* We have a reference to the mark so it should be attached to a
|
|
|
|
* connector.
|
|
|
|
*/
|
|
|
|
if (WARN_ON_ONCE(!chunk->mark.connector))
|
2017-03-14 07:29:35 -06:00
|
|
|
return 0;
|
|
|
|
return (unsigned long)chunk->mark.connector->inode;
|
|
|
|
}
|
|
|
|
|
2016-12-16 02:13:37 -07:00
|
|
|
static inline struct list_head *chunk_hash(unsigned long key)
|
|
|
|
{
|
|
|
|
unsigned long n = key / L1_CACHE_BYTES;
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
return chunk_hash_heads + n % HASH_SIZE;
|
|
|
|
}
|
|
|
|
|
2009-12-17 18:12:05 -07:00
|
|
|
/* hash_lock & entry->lock is held by caller */
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
static void insert_hash(struct audit_chunk *chunk)
|
|
|
|
{
|
2016-12-21 04:15:30 -07:00
|
|
|
unsigned long key = chunk_to_key(chunk);
|
2009-12-17 18:12:05 -07:00
|
|
|
struct list_head *list;
|
|
|
|
|
2017-04-03 08:47:58 -06:00
|
|
|
if (!(chunk->mark.flags & FSNOTIFY_MARK_FLAG_ATTACHED))
|
2009-12-17 18:12:05 -07:00
|
|
|
return;
|
2016-12-16 02:13:37 -07:00
|
|
|
list = chunk_hash(key);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
list_add_rcu(&chunk->hash, list);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* called under rcu_read_lock */
|
|
|
|
struct audit_chunk *audit_tree_lookup(const struct inode *inode)
|
|
|
|
{
|
2016-12-16 02:13:37 -07:00
|
|
|
unsigned long key = inode_to_key(inode);
|
|
|
|
struct list_head *list = chunk_hash(key);
|
2008-05-14 18:10:12 -06:00
|
|
|
struct audit_chunk *p;
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
|
2008-05-14 18:10:12 -06:00
|
|
|
list_for_each_entry_rcu(p, list, hash) {
|
2016-12-16 02:13:37 -07:00
|
|
|
if (chunk_to_key(p) == key) {
|
Fix inotify watch removal/umount races
Inotify watch removals suck violently.
To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex. That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount. We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.
Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done. Cleanup is just deactivate_super().
However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords. That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.
We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable. OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e. that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().
So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong. We had
to drop ih->mutex before we could grab ->s_umount. So the watch
could've been gone already.
That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer. If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address. That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that. Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.
So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check. If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.
And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-14 18:15:43 -07:00
|
|
|
atomic_long_inc(&p->refs);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
return p;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
2015-11-04 06:23:51 -07:00
|
|
|
bool audit_tree_match(struct audit_chunk *chunk, struct audit_tree *tree)
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
{
|
|
|
|
int n;
|
|
|
|
for (n = 0; n < chunk->count; n++)
|
|
|
|
if (chunk->owners[n].owner == tree)
|
2015-11-04 06:23:51 -07:00
|
|
|
return true;
|
|
|
|
return false;
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
/* tagging and untagging inodes with trees */
|
|
|
|
|
Fix inotify watch removal/umount races
Inotify watch removals suck violently.
To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex. That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount. We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.
Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done. Cleanup is just deactivate_super().
However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords. That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.
We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable. OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e. that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().
So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong. We had
to drop ih->mutex before we could grab ->s_umount. So the watch
could've been gone already.
That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer. If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address. That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that. Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.
So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check. If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.
And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-14 18:15:43 -07:00
|
|
|
static struct audit_chunk *find_chunk(struct node *p)
|
|
|
|
{
|
|
|
|
int index = p->index & ~(1U<<31);
|
|
|
|
p -= index;
|
|
|
|
return container_of(p, struct audit_chunk, owners[0]);
|
|
|
|
}
|
|
|
|
|
|
|
|
static void untag_chunk(struct node *p)
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
{
|
Fix inotify watch removal/umount races
Inotify watch removals suck violently.
To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex. That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount. We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.
Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done. Cleanup is just deactivate_super().
However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords. That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.
We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable. OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e. that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().
So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong. We had
to drop ih->mutex before we could grab ->s_umount. So the watch
could've been gone already.
That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer. If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address. That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that. Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.
So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check. If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.
And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-14 18:15:43 -07:00
|
|
|
struct audit_chunk *chunk = find_chunk(p);
|
2009-12-17 19:24:24 -07:00
|
|
|
struct fsnotify_mark *entry = &chunk->mark;
|
2010-10-30 00:18:32 -06:00
|
|
|
struct audit_chunk *new = NULL;
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
struct audit_tree *owner;
|
|
|
|
int size = chunk->count - 1;
|
|
|
|
int i, j;
|
|
|
|
|
2009-12-17 18:12:05 -07:00
|
|
|
fsnotify_get_mark(entry);
|
Fix inotify watch removal/umount races
Inotify watch removals suck violently.
To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex. That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount. We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.
Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done. Cleanup is just deactivate_super().
However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords. That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.
We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable. OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e. that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().
So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong. We had
to drop ih->mutex before we could grab ->s_umount. So the watch
could've been gone already.
That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer. If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address. That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that. Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.
So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check. If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.
And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-14 18:15:43 -07:00
|
|
|
|
|
|
|
spin_unlock(&hash_lock);
|
|
|
|
|
2010-10-30 00:18:32 -06:00
|
|
|
if (size)
|
|
|
|
new = alloc_chunk(size);
|
|
|
|
|
2016-12-14 06:40:05 -07:00
|
|
|
mutex_lock(&entry->group->mark_mutex);
|
2009-12-17 18:12:05 -07:00
|
|
|
spin_lock(&entry->lock);
|
2016-12-21 04:15:30 -07:00
|
|
|
/*
|
|
|
|
* mark_mutex protects mark from getting detached and thus also from
|
|
|
|
* mark->connector->inode getting NULL.
|
|
|
|
*/
|
2017-04-03 08:47:58 -06:00
|
|
|
if (chunk->dead || !(entry->flags & FSNOTIFY_MARK_FLAG_ATTACHED)) {
|
2009-12-17 18:12:05 -07:00
|
|
|
spin_unlock(&entry->lock);
|
2016-12-14 06:40:05 -07:00
|
|
|
mutex_unlock(&entry->group->mark_mutex);
|
2010-10-30 00:18:32 -06:00
|
|
|
if (new)
|
2016-12-21 10:32:48 -07:00
|
|
|
fsnotify_put_mark(&new->mark);
|
Fix inotify watch removal/umount races
Inotify watch removals suck violently.
To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex. That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount. We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.
Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done. Cleanup is just deactivate_super().
However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords. That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.
We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable. OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e. that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().
So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong. We had
to drop ih->mutex before we could grab ->s_umount. So the watch
could've been gone already.
That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer. If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address. That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that. Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.
So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check. If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.
And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-14 18:15:43 -07:00
|
|
|
goto out;
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
owner = p->owner;
|
|
|
|
|
|
|
|
if (!size) {
|
|
|
|
chunk->dead = 1;
|
|
|
|
spin_lock(&hash_lock);
|
|
|
|
list_del_init(&chunk->trees);
|
|
|
|
if (owner->root == chunk)
|
|
|
|
owner->root = NULL;
|
|
|
|
list_del_init(&p->list);
|
|
|
|
list_del_rcu(&chunk->hash);
|
|
|
|
spin_unlock(&hash_lock);
|
2009-12-17 18:12:05 -07:00
|
|
|
spin_unlock(&entry->lock);
|
2016-12-14 06:40:05 -07:00
|
|
|
mutex_unlock(&entry->group->mark_mutex);
|
2011-06-14 09:29:51 -06:00
|
|
|
fsnotify_destroy_mark(entry, audit_tree_group);
|
Fix inotify watch removal/umount races
Inotify watch removals suck violently.
To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex. That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount. We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.
Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done. Cleanup is just deactivate_super().
However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords. That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.
We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable. OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e. that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().
So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong. We had
to drop ih->mutex before we could grab ->s_umount. So the watch
could've been gone already.
That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer. If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address. That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that. Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.
So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check. If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.
And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-14 18:15:43 -07:00
|
|
|
goto out;
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
if (!new)
|
|
|
|
goto Fallback;
|
2010-10-30 00:18:32 -06:00
|
|
|
|
2016-12-21 10:32:48 -07:00
|
|
|
if (fsnotify_add_mark_locked(&new->mark, entry->connector->inode,
|
2016-12-14 06:40:05 -07:00
|
|
|
NULL, 1)) {
|
2012-08-15 04:55:22 -06:00
|
|
|
fsnotify_put_mark(&new->mark);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
goto Fallback;
|
|
|
|
}
|
|
|
|
|
|
|
|
chunk->dead = 1;
|
|
|
|
spin_lock(&hash_lock);
|
|
|
|
list_replace_init(&chunk->trees, &new->trees);
|
|
|
|
if (owner->root == chunk) {
|
|
|
|
list_del_init(&owner->same_root);
|
|
|
|
owner->root = NULL;
|
|
|
|
}
|
|
|
|
|
2009-12-19 08:59:45 -07:00
|
|
|
for (i = j = 0; j <= size; i++, j++) {
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
struct audit_tree *s;
|
|
|
|
if (&chunk->owners[j] == p) {
|
|
|
|
list_del_init(&p->list);
|
|
|
|
i--;
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
s = chunk->owners[j].owner;
|
|
|
|
new->owners[i].owner = s;
|
|
|
|
new->owners[i].index = chunk->owners[j].index - j + i;
|
|
|
|
if (!s) /* result of earlier fallback */
|
|
|
|
continue;
|
|
|
|
get_tree(s);
|
2009-12-19 08:59:45 -07:00
|
|
|
list_replace_init(&chunk->owners[j].list, &new->owners[i].list);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
list_replace_rcu(&chunk->hash, &new->hash);
|
|
|
|
list_for_each_entry(owner, &new->trees, same_root)
|
|
|
|
owner->root = new;
|
|
|
|
spin_unlock(&hash_lock);
|
2009-12-17 18:12:05 -07:00
|
|
|
spin_unlock(&entry->lock);
|
2016-12-14 06:40:05 -07:00
|
|
|
mutex_unlock(&entry->group->mark_mutex);
|
2011-06-14 09:29:51 -06:00
|
|
|
fsnotify_destroy_mark(entry, audit_tree_group);
|
2012-08-15 04:55:22 -06:00
|
|
|
fsnotify_put_mark(&new->mark); /* drop initial reference */
|
Fix inotify watch removal/umount races
Inotify watch removals suck violently.
To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex. That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount. We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.
Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done. Cleanup is just deactivate_super().
However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords. That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.
We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable. OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e. that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().
So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong. We had
to drop ih->mutex before we could grab ->s_umount. So the watch
could've been gone already.
That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer. If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address. That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that. Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.
So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check. If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.
And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-14 18:15:43 -07:00
|
|
|
goto out;
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
|
|
|
|
Fallback:
|
|
|
|
// do the best we can
|
|
|
|
spin_lock(&hash_lock);
|
|
|
|
if (owner->root == chunk) {
|
|
|
|
list_del_init(&owner->same_root);
|
|
|
|
owner->root = NULL;
|
|
|
|
}
|
|
|
|
list_del_init(&p->list);
|
|
|
|
p->owner = NULL;
|
|
|
|
put_tree(owner);
|
|
|
|
spin_unlock(&hash_lock);
|
2009-12-17 18:12:05 -07:00
|
|
|
spin_unlock(&entry->lock);
|
2016-12-14 06:40:05 -07:00
|
|
|
mutex_unlock(&entry->group->mark_mutex);
|
Fix inotify watch removal/umount races
Inotify watch removals suck violently.
To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex. That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount. We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.
Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done. Cleanup is just deactivate_super().
However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords. That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.
We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable. OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e. that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().
So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong. We had
to drop ih->mutex before we could grab ->s_umount. So the watch
could've been gone already.
That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer. If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address. That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that. Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.
So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check. If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.
And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-14 18:15:43 -07:00
|
|
|
out:
|
2009-12-17 18:12:05 -07:00
|
|
|
fsnotify_put_mark(entry);
|
Fix inotify watch removal/umount races
Inotify watch removals suck violently.
To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex. That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount. We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.
Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done. Cleanup is just deactivate_super().
However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords. That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.
We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable. OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e. that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().
So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong. We had
to drop ih->mutex before we could grab ->s_umount. So the watch
could've been gone already.
That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer. If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address. That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that. Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.
So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check. If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.
And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-14 18:15:43 -07:00
|
|
|
spin_lock(&hash_lock);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
static int create_chunk(struct inode *inode, struct audit_tree *tree)
|
|
|
|
{
|
2009-12-17 19:24:24 -07:00
|
|
|
struct fsnotify_mark *entry;
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
struct audit_chunk *chunk = alloc_chunk(1);
|
|
|
|
if (!chunk)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
2009-12-17 18:12:05 -07:00
|
|
|
entry = &chunk->mark;
|
2016-12-21 10:32:48 -07:00
|
|
|
if (fsnotify_add_mark(entry, inode, NULL, 0)) {
|
2012-08-15 04:55:22 -06:00
|
|
|
fsnotify_put_mark(entry);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
return -ENOSPC;
|
|
|
|
}
|
|
|
|
|
2009-12-17 18:12:05 -07:00
|
|
|
spin_lock(&entry->lock);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
spin_lock(&hash_lock);
|
|
|
|
if (tree->goner) {
|
|
|
|
spin_unlock(&hash_lock);
|
|
|
|
chunk->dead = 1;
|
2009-12-17 18:12:05 -07:00
|
|
|
spin_unlock(&entry->lock);
|
2011-06-14 09:29:51 -06:00
|
|
|
fsnotify_destroy_mark(entry, audit_tree_group);
|
2009-12-17 18:12:05 -07:00
|
|
|
fsnotify_put_mark(entry);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
chunk->owners[0].index = (1U << 31);
|
|
|
|
chunk->owners[0].owner = tree;
|
|
|
|
get_tree(tree);
|
|
|
|
list_add(&chunk->owners[0].list, &tree->chunks);
|
|
|
|
if (!tree->root) {
|
|
|
|
tree->root = chunk;
|
|
|
|
list_add(&tree->same_root, &chunk->trees);
|
|
|
|
}
|
|
|
|
insert_hash(chunk);
|
|
|
|
spin_unlock(&hash_lock);
|
2009-12-17 18:12:05 -07:00
|
|
|
spin_unlock(&entry->lock);
|
2012-08-15 04:55:22 -06:00
|
|
|
fsnotify_put_mark(entry); /* drop initial reference */
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* the first tagged inode becomes root of tree */
|
|
|
|
static int tag_chunk(struct inode *inode, struct audit_tree *tree)
|
|
|
|
{
|
2009-12-17 19:24:24 -07:00
|
|
|
struct fsnotify_mark *old_entry, *chunk_entry;
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
struct audit_tree *owner;
|
|
|
|
struct audit_chunk *chunk, *old;
|
|
|
|
struct node *p;
|
|
|
|
int n;
|
|
|
|
|
2016-12-21 08:28:45 -07:00
|
|
|
old_entry = fsnotify_find_mark(&inode->i_fsnotify_marks,
|
|
|
|
audit_tree_group);
|
2009-12-17 18:12:05 -07:00
|
|
|
if (!old_entry)
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
return create_chunk(inode, tree);
|
|
|
|
|
2009-12-17 18:12:05 -07:00
|
|
|
old = container_of(old_entry, struct audit_chunk, mark);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
|
|
|
|
/* are we already there? */
|
|
|
|
spin_lock(&hash_lock);
|
|
|
|
for (n = 0; n < old->count; n++) {
|
|
|
|
if (old->owners[n].owner == tree) {
|
|
|
|
spin_unlock(&hash_lock);
|
2009-12-17 18:12:05 -07:00
|
|
|
fsnotify_put_mark(old_entry);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
spin_unlock(&hash_lock);
|
|
|
|
|
|
|
|
chunk = alloc_chunk(old->count + 1);
|
2009-12-19 09:03:30 -07:00
|
|
|
if (!chunk) {
|
2009-12-17 18:12:05 -07:00
|
|
|
fsnotify_put_mark(old_entry);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
return -ENOMEM;
|
2009-12-19 09:03:30 -07:00
|
|
|
}
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
|
2009-12-17 18:12:05 -07:00
|
|
|
chunk_entry = &chunk->mark;
|
|
|
|
|
2016-12-14 06:40:05 -07:00
|
|
|
mutex_lock(&old_entry->group->mark_mutex);
|
2009-12-17 18:12:05 -07:00
|
|
|
spin_lock(&old_entry->lock);
|
2016-12-21 04:15:30 -07:00
|
|
|
/*
|
|
|
|
* mark_mutex protects mark from getting detached and thus also from
|
|
|
|
* mark->connector->inode getting NULL.
|
|
|
|
*/
|
2017-04-03 08:47:58 -06:00
|
|
|
if (!(old_entry->flags & FSNOTIFY_MARK_FLAG_ATTACHED)) {
|
2009-12-17 18:12:05 -07:00
|
|
|
/* old_entry is being shot, lets just lie */
|
|
|
|
spin_unlock(&old_entry->lock);
|
2016-12-14 06:40:05 -07:00
|
|
|
mutex_unlock(&old_entry->group->mark_mutex);
|
2009-12-17 18:12:05 -07:00
|
|
|
fsnotify_put_mark(old_entry);
|
2016-12-21 10:32:48 -07:00
|
|
|
fsnotify_put_mark(&chunk->mark);
|
2009-12-17 18:12:05 -07:00
|
|
|
return -ENOENT;
|
|
|
|
}
|
|
|
|
|
2016-12-21 10:32:48 -07:00
|
|
|
if (fsnotify_add_mark_locked(chunk_entry,
|
2017-03-14 07:29:35 -06:00
|
|
|
old_entry->connector->inode, NULL, 1)) {
|
2009-12-17 18:12:05 -07:00
|
|
|
spin_unlock(&old_entry->lock);
|
2016-12-14 06:40:05 -07:00
|
|
|
mutex_unlock(&old_entry->group->mark_mutex);
|
2012-08-15 04:55:22 -06:00
|
|
|
fsnotify_put_mark(chunk_entry);
|
2009-12-17 18:12:05 -07:00
|
|
|
fsnotify_put_mark(old_entry);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
return -ENOSPC;
|
|
|
|
}
|
2009-12-17 18:12:05 -07:00
|
|
|
|
|
|
|
/* even though we hold old_entry->lock, this is safe since chunk_entry->lock could NEVER have been grabbed before */
|
|
|
|
spin_lock(&chunk_entry->lock);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
spin_lock(&hash_lock);
|
2009-12-17 18:12:05 -07:00
|
|
|
|
|
|
|
/* we now hold old_entry->lock, chunk_entry->lock, and hash_lock */
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
if (tree->goner) {
|
|
|
|
spin_unlock(&hash_lock);
|
|
|
|
chunk->dead = 1;
|
2009-12-17 18:12:05 -07:00
|
|
|
spin_unlock(&chunk_entry->lock);
|
|
|
|
spin_unlock(&old_entry->lock);
|
2016-12-14 06:40:05 -07:00
|
|
|
mutex_unlock(&old_entry->group->mark_mutex);
|
2009-12-17 18:12:05 -07:00
|
|
|
|
2011-06-14 09:29:51 -06:00
|
|
|
fsnotify_destroy_mark(chunk_entry, audit_tree_group);
|
2009-12-17 18:12:05 -07:00
|
|
|
|
|
|
|
fsnotify_put_mark(chunk_entry);
|
|
|
|
fsnotify_put_mark(old_entry);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
list_replace_init(&old->trees, &chunk->trees);
|
|
|
|
for (n = 0, p = chunk->owners; n < old->count; n++, p++) {
|
|
|
|
struct audit_tree *s = old->owners[n].owner;
|
|
|
|
p->owner = s;
|
|
|
|
p->index = old->owners[n].index;
|
|
|
|
if (!s) /* result of fallback in untag */
|
|
|
|
continue;
|
|
|
|
get_tree(s);
|
|
|
|
list_replace_init(&old->owners[n].list, &p->list);
|
|
|
|
}
|
|
|
|
p->index = (chunk->count - 1) | (1U<<31);
|
|
|
|
p->owner = tree;
|
|
|
|
get_tree(tree);
|
|
|
|
list_add(&p->list, &tree->chunks);
|
|
|
|
list_replace_rcu(&old->hash, &chunk->hash);
|
|
|
|
list_for_each_entry(owner, &chunk->trees, same_root)
|
|
|
|
owner->root = chunk;
|
|
|
|
old->dead = 1;
|
|
|
|
if (!tree->root) {
|
|
|
|
tree->root = chunk;
|
|
|
|
list_add(&tree->same_root, &chunk->trees);
|
|
|
|
}
|
|
|
|
spin_unlock(&hash_lock);
|
2009-12-17 18:12:05 -07:00
|
|
|
spin_unlock(&chunk_entry->lock);
|
|
|
|
spin_unlock(&old_entry->lock);
|
2016-12-14 06:40:05 -07:00
|
|
|
mutex_unlock(&old_entry->group->mark_mutex);
|
2011-06-14 09:29:51 -06:00
|
|
|
fsnotify_destroy_mark(old_entry, audit_tree_group);
|
2012-08-15 04:55:22 -06:00
|
|
|
fsnotify_put_mark(chunk_entry); /* drop initial reference */
|
2009-12-17 18:12:05 -07:00
|
|
|
fsnotify_put_mark(old_entry); /* pair to fsnotify_find mark_entry */
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2014-10-02 20:05:24 -06:00
|
|
|
static void audit_tree_log_remove_rule(struct audit_krule *rule)
|
2013-01-11 15:32:07 -07:00
|
|
|
{
|
|
|
|
struct audit_buffer *ab;
|
|
|
|
|
|
|
|
ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
|
|
|
|
if (unlikely(!ab))
|
|
|
|
return;
|
2016-11-16 14:14:33 -07:00
|
|
|
audit_log_format(ab, "op=remove_rule");
|
2013-01-11 15:32:07 -07:00
|
|
|
audit_log_format(ab, " dir=");
|
|
|
|
audit_log_untrustedstring(ab, rule->tree->pathname);
|
|
|
|
audit_log_key(ab, rule->filterkey);
|
|
|
|
audit_log_format(ab, " list=%d res=1", rule->listnr);
|
|
|
|
audit_log_end(ab);
|
|
|
|
}
|
|
|
|
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
static void kill_rules(struct audit_tree *tree)
|
|
|
|
{
|
|
|
|
struct audit_krule *rule, *next;
|
|
|
|
struct audit_entry *entry;
|
|
|
|
|
|
|
|
list_for_each_entry_safe(rule, next, &tree->rules, rlist) {
|
|
|
|
entry = container_of(rule, struct audit_entry, rule);
|
|
|
|
|
|
|
|
list_del_init(&rule->rlist);
|
|
|
|
if (rule->tree) {
|
|
|
|
/* not a half-baked one */
|
2014-10-02 20:05:24 -06:00
|
|
|
audit_tree_log_remove_rule(rule);
|
2015-08-05 14:29:37 -06:00
|
|
|
if (entry->rule.exe)
|
|
|
|
audit_remove_mark(entry->rule.exe);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
rule->tree = NULL;
|
|
|
|
list_del_rcu(&entry->list);
|
2008-12-14 23:17:50 -07:00
|
|
|
list_del(&entry->rule.list);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
call_rcu(&entry->rcu, audit_free_rule_rcu);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* finish killing struct audit_tree
|
|
|
|
*/
|
|
|
|
static void prune_one(struct audit_tree *victim)
|
|
|
|
{
|
|
|
|
spin_lock(&hash_lock);
|
|
|
|
while (!list_empty(&victim->chunks)) {
|
|
|
|
struct node *p;
|
|
|
|
|
|
|
|
p = list_entry(victim->chunks.next, struct node, list);
|
|
|
|
|
Fix inotify watch removal/umount races
Inotify watch removals suck violently.
To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex. That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount. We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.
Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done. Cleanup is just deactivate_super().
However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords. That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.
We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable. OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e. that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().
So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong. We had
to drop ih->mutex before we could grab ->s_umount. So the watch
could've been gone already.
That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer. If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address. That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that. Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.
So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check. If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.
And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-14 18:15:43 -07:00
|
|
|
untag_chunk(p);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
}
|
|
|
|
spin_unlock(&hash_lock);
|
|
|
|
put_tree(victim);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* trim the uncommitted chunks from tree */
|
|
|
|
|
|
|
|
static void trim_marked(struct audit_tree *tree)
|
|
|
|
{
|
|
|
|
struct list_head *p, *q;
|
|
|
|
spin_lock(&hash_lock);
|
|
|
|
if (tree->goner) {
|
|
|
|
spin_unlock(&hash_lock);
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
/* reorder */
|
|
|
|
for (p = tree->chunks.next; p != &tree->chunks; p = q) {
|
|
|
|
struct node *node = list_entry(p, struct node, list);
|
|
|
|
q = p->next;
|
|
|
|
if (node->index & (1U<<31)) {
|
|
|
|
list_del_init(p);
|
|
|
|
list_add(p, &tree->chunks);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
while (!list_empty(&tree->chunks)) {
|
|
|
|
struct node *node;
|
|
|
|
|
|
|
|
node = list_entry(tree->chunks.next, struct node, list);
|
|
|
|
|
|
|
|
/* have we run out of marked? */
|
|
|
|
if (!(node->index & (1U<<31)))
|
|
|
|
break;
|
|
|
|
|
Fix inotify watch removal/umount races
Inotify watch removals suck violently.
To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex. That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount. We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.
Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done. Cleanup is just deactivate_super().
However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords. That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.
We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable. OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e. that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().
So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong. We had
to drop ih->mutex before we could grab ->s_umount. So the watch
could've been gone already.
That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer. If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address. That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that. Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.
So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check. If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.
And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-14 18:15:43 -07:00
|
|
|
untag_chunk(node);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
}
|
|
|
|
if (!tree->root && !tree->goner) {
|
|
|
|
tree->goner = 1;
|
|
|
|
spin_unlock(&hash_lock);
|
|
|
|
mutex_lock(&audit_filter_mutex);
|
|
|
|
kill_rules(tree);
|
|
|
|
list_del_init(&tree->list);
|
|
|
|
mutex_unlock(&audit_filter_mutex);
|
|
|
|
prune_one(tree);
|
|
|
|
} else {
|
|
|
|
spin_unlock(&hash_lock);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2009-06-23 22:02:38 -06:00
|
|
|
static void audit_schedule_prune(void);
|
|
|
|
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
/* called with audit_filter_mutex */
|
|
|
|
int audit_remove_tree_rule(struct audit_krule *rule)
|
|
|
|
{
|
|
|
|
struct audit_tree *tree;
|
|
|
|
tree = rule->tree;
|
|
|
|
if (tree) {
|
|
|
|
spin_lock(&hash_lock);
|
|
|
|
list_del_init(&rule->rlist);
|
|
|
|
if (list_empty(&tree->rules) && !tree->goner) {
|
|
|
|
tree->root = NULL;
|
|
|
|
list_del_init(&tree->same_root);
|
|
|
|
tree->goner = 1;
|
|
|
|
list_move(&tree->list, &prune_list);
|
|
|
|
rule->tree = NULL;
|
|
|
|
spin_unlock(&hash_lock);
|
|
|
|
audit_schedule_prune();
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
rule->tree = NULL;
|
|
|
|
spin_unlock(&hash_lock);
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2010-01-30 20:51:25 -07:00
|
|
|
static int compare_root(struct vfsmount *mnt, void *arg)
|
|
|
|
{
|
2016-12-16 02:13:37 -07:00
|
|
|
return inode_to_key(d_backing_inode(mnt->mnt_root)) ==
|
|
|
|
(unsigned long)arg;
|
2010-01-30 20:51:25 -07:00
|
|
|
}
|
|
|
|
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
void audit_trim_trees(void)
|
|
|
|
{
|
|
|
|
struct list_head cursor;
|
|
|
|
|
|
|
|
mutex_lock(&audit_filter_mutex);
|
|
|
|
list_add(&cursor, &tree_list);
|
|
|
|
while (cursor.next != &tree_list) {
|
|
|
|
struct audit_tree *tree;
|
2008-08-01 23:06:21 -06:00
|
|
|
struct path path;
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
struct vfsmount *root_mnt;
|
|
|
|
struct node *node;
|
|
|
|
int err;
|
|
|
|
|
|
|
|
tree = container_of(cursor.next, struct audit_tree, list);
|
|
|
|
get_tree(tree);
|
|
|
|
list_del(&cursor);
|
|
|
|
list_add(&cursor, &tree->list);
|
|
|
|
mutex_unlock(&audit_filter_mutex);
|
|
|
|
|
2008-08-01 23:06:21 -06:00
|
|
|
err = kern_path(tree->pathname, 0, &path);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
if (err)
|
|
|
|
goto skip_it;
|
|
|
|
|
2009-04-18 01:28:19 -06:00
|
|
|
root_mnt = collect_mounts(&path);
|
2008-08-01 23:06:21 -06:00
|
|
|
path_put(&path);
|
2012-06-25 05:55:18 -06:00
|
|
|
if (IS_ERR(root_mnt))
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
goto skip_it;
|
|
|
|
|
|
|
|
spin_lock(&hash_lock);
|
|
|
|
list_for_each_entry(node, &tree->chunks, list) {
|
2009-12-17 18:12:05 -07:00
|
|
|
struct audit_chunk *chunk = find_chunk(node);
|
2011-03-30 19:57:33 -06:00
|
|
|
/* this could be NULL if the watch is dying else where... */
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
node->index |= 1U<<31;
|
2016-12-16 02:13:37 -07:00
|
|
|
if (iterate_mounts(compare_root,
|
|
|
|
(void *)chunk_to_key(chunk),
|
|
|
|
root_mnt))
|
2010-01-30 20:51:25 -07:00
|
|
|
node->index &= ~(1U<<31);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
}
|
|
|
|
spin_unlock(&hash_lock);
|
|
|
|
trim_marked(tree);
|
|
|
|
drop_collected_mounts(root_mnt);
|
|
|
|
skip_it:
|
2013-04-29 16:05:19 -06:00
|
|
|
put_tree(tree);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
mutex_lock(&audit_filter_mutex);
|
|
|
|
}
|
|
|
|
list_del(&cursor);
|
|
|
|
mutex_unlock(&audit_filter_mutex);
|
|
|
|
}
|
|
|
|
|
|
|
|
int audit_make_tree(struct audit_krule *rule, char *pathname, u32 op)
|
|
|
|
{
|
|
|
|
|
|
|
|
if (pathname[0] != '/' ||
|
|
|
|
rule->listnr != AUDIT_FILTER_EXIT ||
|
2008-12-16 03:59:26 -07:00
|
|
|
op != Audit_equal ||
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
rule->inode_f || rule->watch || rule->tree)
|
|
|
|
return -EINVAL;
|
|
|
|
rule->tree = alloc_tree(pathname);
|
|
|
|
if (!rule->tree)
|
|
|
|
return -ENOMEM;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
void audit_put_tree(struct audit_tree *tree)
|
|
|
|
{
|
|
|
|
put_tree(tree);
|
|
|
|
}
|
|
|
|
|
2010-01-30 20:51:25 -07:00
|
|
|
static int tag_mount(struct vfsmount *mnt, void *arg)
|
|
|
|
{
|
2015-03-17 16:26:21 -06:00
|
|
|
return tag_chunk(d_backing_inode(mnt->mnt_root), arg);
|
2010-01-30 20:51:25 -07:00
|
|
|
}
|
|
|
|
|
2015-02-23 13:37:59 -07:00
|
|
|
/*
|
|
|
|
* That gets run when evict_chunk() ends up needing to kill audit_tree.
|
|
|
|
* Runs from a separate thread.
|
|
|
|
*/
|
|
|
|
static int prune_tree_thread(void *unused)
|
|
|
|
{
|
|
|
|
for (;;) {
|
2016-03-31 02:49:28 -06:00
|
|
|
if (list_empty(&prune_list)) {
|
|
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
2015-02-23 13:37:59 -07:00
|
|
|
schedule();
|
2016-03-31 02:49:28 -06:00
|
|
|
}
|
2015-02-23 13:37:59 -07:00
|
|
|
|
|
|
|
mutex_lock(&audit_cmd_mutex);
|
|
|
|
mutex_lock(&audit_filter_mutex);
|
|
|
|
|
|
|
|
while (!list_empty(&prune_list)) {
|
|
|
|
struct audit_tree *victim;
|
|
|
|
|
|
|
|
victim = list_entry(prune_list.next,
|
|
|
|
struct audit_tree, list);
|
|
|
|
list_del_init(&victim->list);
|
|
|
|
|
|
|
|
mutex_unlock(&audit_filter_mutex);
|
|
|
|
|
|
|
|
prune_one(victim);
|
|
|
|
|
|
|
|
mutex_lock(&audit_filter_mutex);
|
|
|
|
}
|
|
|
|
|
|
|
|
mutex_unlock(&audit_filter_mutex);
|
|
|
|
mutex_unlock(&audit_cmd_mutex);
|
|
|
|
}
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int audit_launch_prune(void)
|
|
|
|
{
|
|
|
|
if (prune_thread)
|
|
|
|
return 0;
|
2016-03-31 02:49:28 -06:00
|
|
|
prune_thread = kthread_run(prune_tree_thread, NULL,
|
2015-02-23 13:37:59 -07:00
|
|
|
"audit_prune_tree");
|
|
|
|
if (IS_ERR(prune_thread)) {
|
|
|
|
pr_err("cannot start thread audit_prune_tree");
|
|
|
|
prune_thread = NULL;
|
|
|
|
return -ENOMEM;
|
|
|
|
}
|
2016-03-31 02:49:28 -06:00
|
|
|
return 0;
|
2015-02-23 13:37:59 -07:00
|
|
|
}
|
|
|
|
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
/* called with audit_filter_mutex */
|
|
|
|
int audit_add_tree_rule(struct audit_krule *rule)
|
|
|
|
{
|
|
|
|
struct audit_tree *seed = rule->tree, *tree;
|
2008-08-01 23:06:21 -06:00
|
|
|
struct path path;
|
2010-01-30 20:51:25 -07:00
|
|
|
struct vfsmount *mnt;
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
int err;
|
|
|
|
|
2013-06-12 15:05:07 -06:00
|
|
|
rule->tree = NULL;
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
list_for_each_entry(tree, &tree_list, list) {
|
|
|
|
if (!strcmp(seed->pathname, tree->pathname)) {
|
|
|
|
put_tree(seed);
|
|
|
|
rule->tree = tree;
|
|
|
|
list_add(&rule->rlist, &tree->rules);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
tree = seed;
|
|
|
|
list_add(&tree->list, &tree_list);
|
|
|
|
list_add(&rule->rlist, &tree->rules);
|
|
|
|
/* do not set rule->tree yet */
|
|
|
|
mutex_unlock(&audit_filter_mutex);
|
|
|
|
|
2015-02-23 13:37:59 -07:00
|
|
|
if (unlikely(!prune_thread)) {
|
|
|
|
err = audit_launch_prune();
|
|
|
|
if (err)
|
|
|
|
goto Err;
|
|
|
|
}
|
|
|
|
|
2008-08-01 23:06:21 -06:00
|
|
|
err = kern_path(tree->pathname, 0, &path);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
if (err)
|
|
|
|
goto Err;
|
2009-04-18 01:28:19 -06:00
|
|
|
mnt = collect_mounts(&path);
|
2008-08-01 23:06:21 -06:00
|
|
|
path_put(&path);
|
2012-06-25 05:55:18 -06:00
|
|
|
if (IS_ERR(mnt)) {
|
|
|
|
err = PTR_ERR(mnt);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
goto Err;
|
|
|
|
}
|
|
|
|
|
|
|
|
get_tree(tree);
|
2010-01-30 20:51:25 -07:00
|
|
|
err = iterate_mounts(tag_mount, tree, mnt);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
drop_collected_mounts(mnt);
|
|
|
|
|
|
|
|
if (!err) {
|
|
|
|
struct node *node;
|
|
|
|
spin_lock(&hash_lock);
|
|
|
|
list_for_each_entry(node, &tree->chunks, list)
|
|
|
|
node->index &= ~(1U<<31);
|
|
|
|
spin_unlock(&hash_lock);
|
|
|
|
} else {
|
|
|
|
trim_marked(tree);
|
|
|
|
goto Err;
|
|
|
|
}
|
|
|
|
|
|
|
|
mutex_lock(&audit_filter_mutex);
|
|
|
|
if (list_empty(&rule->rlist)) {
|
|
|
|
put_tree(tree);
|
|
|
|
return -ENOENT;
|
|
|
|
}
|
|
|
|
rule->tree = tree;
|
|
|
|
put_tree(tree);
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
Err:
|
|
|
|
mutex_lock(&audit_filter_mutex);
|
|
|
|
list_del_init(&tree->list);
|
|
|
|
list_del_init(&tree->rules);
|
|
|
|
put_tree(tree);
|
|
|
|
return err;
|
|
|
|
}
|
|
|
|
|
|
|
|
int audit_tag_tree(char *old, char *new)
|
|
|
|
{
|
|
|
|
struct list_head cursor, barrier;
|
|
|
|
int failed = 0;
|
2010-01-30 11:16:21 -07:00
|
|
|
struct path path1, path2;
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
struct vfsmount *tagged;
|
|
|
|
int err;
|
|
|
|
|
2010-01-30 11:16:21 -07:00
|
|
|
err = kern_path(new, 0, &path2);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
if (err)
|
|
|
|
return err;
|
2010-01-30 11:16:21 -07:00
|
|
|
tagged = collect_mounts(&path2);
|
|
|
|
path_put(&path2);
|
2012-06-25 05:55:18 -06:00
|
|
|
if (IS_ERR(tagged))
|
|
|
|
return PTR_ERR(tagged);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
|
2010-01-30 11:16:21 -07:00
|
|
|
err = kern_path(old, 0, &path1);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
if (err) {
|
|
|
|
drop_collected_mounts(tagged);
|
|
|
|
return err;
|
|
|
|
}
|
|
|
|
|
|
|
|
mutex_lock(&audit_filter_mutex);
|
|
|
|
list_add(&barrier, &tree_list);
|
|
|
|
list_add(&cursor, &barrier);
|
|
|
|
|
|
|
|
while (cursor.next != &tree_list) {
|
|
|
|
struct audit_tree *tree;
|
2010-01-30 11:16:21 -07:00
|
|
|
int good_one = 0;
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
|
|
|
|
tree = container_of(cursor.next, struct audit_tree, list);
|
|
|
|
get_tree(tree);
|
|
|
|
list_del(&cursor);
|
|
|
|
list_add(&cursor, &tree->list);
|
|
|
|
mutex_unlock(&audit_filter_mutex);
|
|
|
|
|
2010-01-30 11:16:21 -07:00
|
|
|
err = kern_path(tree->pathname, 0, &path2);
|
|
|
|
if (!err) {
|
|
|
|
good_one = path_is_under(&path1, &path2);
|
|
|
|
path_put(&path2);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
}
|
|
|
|
|
2010-01-30 11:16:21 -07:00
|
|
|
if (!good_one) {
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
put_tree(tree);
|
|
|
|
mutex_lock(&audit_filter_mutex);
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
2010-01-30 20:51:25 -07:00
|
|
|
failed = iterate_mounts(tag_mount, tree, tagged);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
if (failed) {
|
|
|
|
put_tree(tree);
|
|
|
|
mutex_lock(&audit_filter_mutex);
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
mutex_lock(&audit_filter_mutex);
|
|
|
|
spin_lock(&hash_lock);
|
|
|
|
if (!tree->goner) {
|
|
|
|
list_del(&tree->list);
|
|
|
|
list_add(&tree->list, &tree_list);
|
|
|
|
}
|
|
|
|
spin_unlock(&hash_lock);
|
|
|
|
put_tree(tree);
|
|
|
|
}
|
|
|
|
|
|
|
|
while (barrier.prev != &tree_list) {
|
|
|
|
struct audit_tree *tree;
|
|
|
|
|
|
|
|
tree = container_of(barrier.prev, struct audit_tree, list);
|
|
|
|
get_tree(tree);
|
|
|
|
list_del(&tree->list);
|
|
|
|
list_add(&tree->list, &barrier);
|
|
|
|
mutex_unlock(&audit_filter_mutex);
|
|
|
|
|
|
|
|
if (!failed) {
|
|
|
|
struct node *node;
|
|
|
|
spin_lock(&hash_lock);
|
|
|
|
list_for_each_entry(node, &tree->chunks, list)
|
|
|
|
node->index &= ~(1U<<31);
|
|
|
|
spin_unlock(&hash_lock);
|
|
|
|
} else {
|
|
|
|
trim_marked(tree);
|
|
|
|
}
|
|
|
|
|
|
|
|
put_tree(tree);
|
|
|
|
mutex_lock(&audit_filter_mutex);
|
|
|
|
}
|
|
|
|
list_del(&barrier);
|
|
|
|
list_del(&cursor);
|
|
|
|
mutex_unlock(&audit_filter_mutex);
|
2010-01-30 11:16:21 -07:00
|
|
|
path_put(&path1);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
drop_collected_mounts(tagged);
|
|
|
|
return failed;
|
|
|
|
}
|
|
|
|
|
2009-06-23 22:02:38 -06:00
|
|
|
|
|
|
|
static void audit_schedule_prune(void)
|
|
|
|
{
|
2015-02-23 13:37:59 -07:00
|
|
|
wake_up_process(prune_thread);
|
2009-06-23 22:02:38 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* ... and that one is done if evict_chunk() decides to delay until the end
|
|
|
|
* of syscall. Runs synchronously.
|
|
|
|
*/
|
|
|
|
void audit_kill_trees(struct list_head *list)
|
|
|
|
{
|
|
|
|
mutex_lock(&audit_cmd_mutex);
|
|
|
|
mutex_lock(&audit_filter_mutex);
|
|
|
|
|
|
|
|
while (!list_empty(list)) {
|
|
|
|
struct audit_tree *victim;
|
|
|
|
|
|
|
|
victim = list_entry(list->next, struct audit_tree, list);
|
|
|
|
kill_rules(victim);
|
|
|
|
list_del_init(&victim->list);
|
|
|
|
|
|
|
|
mutex_unlock(&audit_filter_mutex);
|
|
|
|
|
|
|
|
prune_one(victim);
|
|
|
|
|
|
|
|
mutex_lock(&audit_filter_mutex);
|
|
|
|
}
|
|
|
|
|
|
|
|
mutex_unlock(&audit_filter_mutex);
|
|
|
|
mutex_unlock(&audit_cmd_mutex);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Here comes the stuff asynchronous to auditctl operations
|
|
|
|
*/
|
|
|
|
|
|
|
|
static void evict_chunk(struct audit_chunk *chunk)
|
|
|
|
{
|
|
|
|
struct audit_tree *owner;
|
2009-06-23 22:02:38 -06:00
|
|
|
struct list_head *postponed = audit_killed_trees();
|
|
|
|
int need_prune = 0;
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
int n;
|
|
|
|
|
|
|
|
if (chunk->dead)
|
|
|
|
return;
|
|
|
|
|
|
|
|
chunk->dead = 1;
|
|
|
|
mutex_lock(&audit_filter_mutex);
|
|
|
|
spin_lock(&hash_lock);
|
|
|
|
while (!list_empty(&chunk->trees)) {
|
|
|
|
owner = list_entry(chunk->trees.next,
|
|
|
|
struct audit_tree, same_root);
|
|
|
|
owner->goner = 1;
|
|
|
|
owner->root = NULL;
|
|
|
|
list_del_init(&owner->same_root);
|
|
|
|
spin_unlock(&hash_lock);
|
2009-06-23 22:02:38 -06:00
|
|
|
if (!postponed) {
|
|
|
|
kill_rules(owner);
|
|
|
|
list_move(&owner->list, &prune_list);
|
|
|
|
need_prune = 1;
|
|
|
|
} else {
|
|
|
|
list_move(&owner->list, postponed);
|
|
|
|
}
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
spin_lock(&hash_lock);
|
|
|
|
}
|
|
|
|
list_del_rcu(&chunk->hash);
|
|
|
|
for (n = 0; n < chunk->count; n++)
|
|
|
|
list_del_init(&chunk->owners[n].list);
|
|
|
|
spin_unlock(&hash_lock);
|
2015-02-23 13:37:59 -07:00
|
|
|
mutex_unlock(&audit_filter_mutex);
|
2009-06-23 22:02:38 -06:00
|
|
|
if (need_prune)
|
|
|
|
audit_schedule_prune();
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
}
|
|
|
|
|
2010-07-28 08:18:38 -06:00
|
|
|
static int audit_tree_handle_event(struct fsnotify_group *group,
|
2014-01-21 16:48:14 -07:00
|
|
|
struct inode *to_tell,
|
2010-07-28 08:18:39 -06:00
|
|
|
struct fsnotify_mark *inode_mark,
|
2014-01-21 16:48:14 -07:00
|
|
|
struct fsnotify_mark *vfsmount_mark,
|
2016-11-20 18:19:09 -07:00
|
|
|
u32 mask, const void *data, int data_type,
|
2016-11-10 09:51:50 -07:00
|
|
|
const unsigned char *file_name, u32 cookie,
|
|
|
|
struct fsnotify_iter_info *iter_info)
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
{
|
2014-01-21 16:48:15 -07:00
|
|
|
return 0;
|
2009-12-17 18:12:05 -07:00
|
|
|
}
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
|
2009-12-17 19:24:24 -07:00
|
|
|
static void audit_tree_freeing_mark(struct fsnotify_mark *entry, struct fsnotify_group *group)
|
2009-12-17 18:12:05 -07:00
|
|
|
{
|
|
|
|
struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark);
|
|
|
|
|
|
|
|
evict_chunk(chunk);
|
2012-08-15 04:55:22 -06:00
|
|
|
|
|
|
|
/*
|
|
|
|
* We are guaranteed to have at least one reference to the mark from
|
|
|
|
* either the inode or the caller of fsnotify_destroy_mark().
|
|
|
|
*/
|
|
|
|
BUG_ON(atomic_read(&entry->refcnt) < 1);
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
}
|
|
|
|
|
2009-12-17 18:12:05 -07:00
|
|
|
static const struct fsnotify_ops audit_tree_ops = {
|
|
|
|
.handle_event = audit_tree_handle_event,
|
|
|
|
.freeing_mark = audit_tree_freeing_mark,
|
2016-12-21 10:06:12 -07:00
|
|
|
.free_mark = audit_tree_destroy_watch,
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
};
|
|
|
|
|
|
|
|
static int __init audit_tree_init(void)
|
|
|
|
{
|
|
|
|
int i;
|
|
|
|
|
2009-12-17 19:24:22 -07:00
|
|
|
audit_tree_group = fsnotify_alloc_group(&audit_tree_ops);
|
2009-12-17 18:12:05 -07:00
|
|
|
if (IS_ERR(audit_tree_group))
|
|
|
|
audit_panic("cannot initialize fsnotify group for rectree watches");
|
[PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-07-22 06:04:18 -06:00
|
|
|
|
|
|
|
for (i = 0; i < HASH_SIZE; i++)
|
|
|
|
INIT_LIST_HEAD(&chunk_hash_heads[i]);
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
__initcall(audit_tree_init);
|