remarkable-linux/fs
Eric Biggers f734076181 pipe: read buffer limits atomically
The pipe buffer limits are accessed without any locking, and may be
changed at any time by the sysctl handlers.  In theory this could cause
problems for expressions like the following:

    pipe_user_pages_hard && user_bufs > pipe_user_pages_hard

...  since the assembly code might reference the 'pipe_user_pages_hard'
memory location multiple times, and if the admin removes the limit by
setting it to 0, there is a very brief window where processes could
incorrectly observe the limit to be exceeded.

Fix this by loading the limits with READ_ONCE() prior to use.

Link: http://lkml.kernel.org/r/20180111052902.14409-8-ebiggers3@gmail.com
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: "Luis R . Rodriguez" <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:48 -08:00
..
9p fs/*/Kconfig: drop links to 404-compliant http://acl.bestbits.at 2018-01-01 12:45:37 -07:00
adfs Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
affs affs: convert to new i_version API 2018-01-29 06:42:20 -05:00
afs inode->i_version rework for v4.16 2018-01-29 13:33:53 -08:00
autofs4 Merge branch 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2018-01-30 14:43:12 -08:00
befs befs: Define usercopy region in befs_inode_cache slab cache 2018-01-15 12:07:54 -08:00
bfs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
btrfs Documentation updates for 4.16. New stuff includes refcount_t 2018-01-31 19:25:25 -08:00
cachefiles fs: annotate ->poll() instances 2017-11-27 16:20:05 -05:00
ceph Documentation updates for 4.16. New stuff includes refcount_t 2018-01-31 19:25:25 -08:00
cifs Currently, hardened usercopy performs dynamic bounds checking on slab 2018-02-03 16:25:42 -08:00
coda Merge branch 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-01-30 17:58:07 -08:00
configfs configfs: make ci_type field, some pointers and function arguments const 2017-10-19 16:15:16 +02:00
cramfs cramfs: fix MTD dependency 2017-12-17 12:20:58 -08:00
crypto fscrypt: fix build with pre-4.6 gcc versions 2018-02-01 10:51:18 -05:00
debugfs fs: annotate ->poll() instances 2017-11-27 16:20:05 -05:00
devpts devpts: fix error handling in devpts_mntget() 2018-01-31 08:48:37 -08:00
dlm Merge branch 'work.sock_recvmsg' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-01-30 18:59:03 -08:00
ecryptfs Merge branch 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-01-30 17:58:07 -08:00
efivarfs VFS: Kill off s_options and helpers 2017-07-11 06:09:21 -04:00
efs Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
exofs Currently, hardened usercopy performs dynamic bounds checking on slab 2018-02-03 16:25:42 -08:00
exportfs
ext2 Currently, hardened usercopy performs dynamic bounds checking on slab 2018-02-03 16:25:42 -08:00
ext4 Refactor support for encrypted symlinks to move common code to fscrypt. 2018-02-04 10:43:12 -08:00
f2fs Refactor support for encrypted symlinks to move common code to fscrypt. 2018-02-04 10:43:12 -08:00
fat fat: convert to new i_version API 2018-01-29 06:42:20 -05:00
freevxfs vxfs: Define usercopy region in vxfs_inode slab cache 2018-01-15 12:07:57 -08:00
fscache AFS development 2017-11-16 11:41:22 -08:00
fuse Merge branch 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-01-30 17:58:07 -08:00
gfs2 gfs2: Glock dump performance regression fix 2018-02-01 11:27:11 -07:00
hfs Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
hfsplus hfsplus: honor setgid flag on directories 2018-02-06 18:32:45 -08:00
hostfs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hpfs hpfs: don't bother with the i_version counter or f_version 2017-12-10 12:58:18 -08:00
hugetlbfs hugetlb: implement memfd sealing 2018-01-31 17:18:39 -08:00
isofs Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
jbd2 jbd2: fix sphinx kernel-doc build warnings 2018-01-10 00:27:29 -05:00
jffs2 Documentation updates for 4.16. New stuff includes refcount_t 2018-01-31 19:25:25 -08:00
jfs Currently, hardened usercopy performs dynamic bounds checking on slab 2018-02-03 16:25:42 -08:00
kernfs Merge branch 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-01-30 17:58:07 -08:00
lockd lockd: Fix server refcounting 2018-01-24 17:33:57 -05:00
minix Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
nfs Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-01-31 09:25:20 -08:00
nfs_common lockd: fix "list_add double add" caused by legacy signal interface 2017-11-27 16:45:11 -05:00
nfsd inode->i_version rework for v4.16 2018-01-29 13:33:53 -08:00
nilfs2 nilfs2: use time64_t internally 2018-02-06 18:32:45 -08:00
nls License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
notify Merge branch 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-01-30 17:58:07 -08:00
ntfs ntfs: remove i_version handling 2018-01-01 10:09:33 -05:00
ocfs2 ocfs2: return error when we attempt to access a dirty bh in jbd2 2018-01-31 17:18:35 -08:00
omfs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
openpromfs Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
orangefs Currently, hardened usercopy performs dynamic bounds checking on slab 2018-02-03 16:25:42 -08:00
overlayfs ovl: check ERR_PTR() return value from ovl_encode_fh() 2018-02-05 09:50:29 +01:00
proc fs/proc/consoles.c: use seq_putc() in show_console_dev() 2018-02-06 18:32:44 -08:00
pstore fs: pstore: remove unused hardirq.h 2017-11-28 16:39:09 -08:00
qnx4 Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
qnx6 Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
quota quota: Check for register_shrinker() failure. 2017-11-29 16:46:48 +01:00
ramfs mm: make pagevec_lookup() update index 2017-09-06 17:27:26 -07:00
reiserfs fs/*/Kconfig: drop links to 404-compliant http://acl.bestbits.at 2018-01-01 12:45:37 -07:00
romfs Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
squashfs Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
sysfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk 2018-02-01 13:36:15 -08:00
sysv Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
tracefs VFS: Don't use save/replace_mount_options if not using generic_show_options 2017-07-06 03:31:46 -04:00
ubifs Refactor support for encrypted symlinks to move common code to fscrypt. 2018-02-04 10:43:12 -08:00
udf Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
ufs Currently, hardened usercopy performs dynamic bounds checking on slab 2018-02-03 16:25:42 -08:00
xfs Changes since last update: 2018-02-05 13:35:56 -08:00
aio.c Merge branch 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-11-17 11:54:55 -08:00
anon_inodes.c
attr.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
bad_inode.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
binfmt_aout.c fs: fix kernel_read prototype 2017-09-04 19:05:15 -04:00
binfmt_elf.c elf: fix NT_FILE integer overflow 2018-02-06 18:32:45 -08:00
binfmt_elf_fdpic.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-11-17 12:54:01 -08:00
binfmt_em86.c
binfmt_flat.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
binfmt_misc.c fs/binfmt_misc.c: node could be NULL when evicting inode 2017-10-13 16:18:33 -07:00
binfmt_script.c exec: load_script: kill the onstack interp[BINPRM_BUF_SIZE] array 2017-10-03 17:54:25 -07:00
block_dev.c Merge branch 'for-4.15/block' of git://git.kernel.dk/linux-block 2017-11-14 15:32:19 -08:00
buffer.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-01-31 09:25:20 -08:00
char_dev.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
compat.c
compat_binfmt_elf.c
compat_ioctl.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-11-17 12:54:01 -08:00
coredump.c Merge branch 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-11-17 11:54:55 -08:00
dax.c Only miscellaneous cleanups and bug fixes for ext4 this cycle. 2018-02-03 13:49:22 -08:00
dcache.c Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs 2018-02-05 13:05:20 -08:00
dcookies.c
direct-io.c iomap: report collisions between directio and buffered writes to userspace 2018-01-08 10:41:39 -08:00
drop_caches.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
eventfd.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-01-31 09:25:20 -08:00
eventpoll.c eventpoll: no need to mask the result of epi_item_poll() again 2017-11-28 19:56:15 -05:00
exec.c exec: Weaken dumpability for secureexec 2018-01-03 10:13:36 -08:00
fcntl.c shmem: rename functions that are memfd-related 2018-01-31 17:18:39 -08:00
fhandle.c vfs: Copy struct mount.mnt_id to userspace using put_user() 2018-01-15 12:07:51 -08:00
file.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-01-31 09:25:20 -08:00
file_table.c vfs: remove unused hardirq.h 2017-12-07 14:23:30 -05:00
filesystems.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fs-writeback.c writeback: update comment in inode_io_list_move_locked 2018-01-06 09:18:00 -07:00
fs_pin.c Merge branch 'linus' into locking/core, to resolve conflicts 2017-11-07 10:32:44 +01:00
fs_struct.c
inode.c vfs: remove might_sleep() from clear_inode() 2018-02-06 18:32:47 -08:00
internal.h fs: expose do_unlinkat for built-in callers 2017-11-10 08:48:46 -05:00
ioctl.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
iomap.c iomap: warn on zero-length mappings 2018-01-29 07:27:24 -08:00
Kconfig Staging/IIO patches for 4.16-rc1 2018-02-01 09:51:57 -08:00
Kconfig.binfmt ARM: enable elf_fdpic on systems with an MMU 2017-09-10 19:31:46 -04:00
libfs.c Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
locks.c Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
Makefile ncpfs: move net/ncpfs to drivers/staging/ncpfs 2017-11-28 13:55:01 +01:00
mbcache.c mbcache: make sure c_entry_count is not decremented past zero 2018-01-09 23:57:52 -05:00
mount.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mpage.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
namei.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-01-31 09:25:20 -08:00
namespace.c VFS: Handle lazytime in do_mount() 2017-12-09 20:16:33 -05:00
no-block.c
nsfs.c nsfs: generalize ns_get_path() for path resolution with a task 2017-12-31 16:12:23 +01:00
open.c ovl: don't allow writing ioctl on lower layer 2017-09-05 12:53:12 +02:00
pipe.c pipe: read buffer limits atomically 2018-02-06 18:32:48 -08:00
pnode.c mnt: Make propagate_umount less slow for overlapping mount propagation trees 2017-05-23 08:41:17 -05:00
pnode.h
posix_acl.c posix_acl: convert posix_acl.a_refcount from atomic_t to refcount_t 2018-01-02 19:27:28 -08:00
proc_namespace.c Merge branch 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-01-30 17:58:07 -08:00
read_write.c Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-11-17 12:08:18 -08:00
readdir.c Merge branch 'linus' into locking/core, to resolve conflicts 2017-11-07 10:32:44 +01:00
select.c make kernel-side POLL... arch-independent 2017-11-29 19:00:41 -05:00
seq_file.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
signalfd.c fs: annotate ->poll() instances 2017-11-27 16:20:05 -05:00
splice.c locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE() 2017-10-25 11:01:08 +02:00
stack.c
stat.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
statfs.c Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
super.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-01-31 09:25:20 -08:00
sync.c Merge branch 'for-4.15/block' of git://git.kernel.dk/linux-block 2017-11-14 15:32:19 -08:00
timerfd.c fs: annotate ->poll() instances 2017-11-27 16:20:05 -05:00
userfaultfd.c userfaultfd: convert to use anon_inode_getfd() 2018-01-31 17:18:39 -08:00
utimes.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xattr.c lsm: fix smack_inode_removexattr and xattr_getsecurity memleak 2017-10-04 18:03:15 +11:00