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alistair23-linux/security/tomoyo/audit.c
Linus Torvalds a9a08845e9 vfs: do bulk POLL* -> EPOLL* replacement 
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

    for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
        L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
        for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
    done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do.  But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.

Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-11 14:34:03 -08:00

470 lines
12 KiB
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// SPDX-License-Identifier: GPL-2.0
/*
* security/tomoyo/audit.c
*
* Copyright (C) 2005-2011 NTT DATA CORPORATION
*/
#include "common.h"
#include <linux/slab.h>
/**
* tomoyo_print_bprm - Print "struct linux_binprm" for auditing.
*
* @bprm: Pointer to "struct linux_binprm".
* @dump: Pointer to "struct tomoyo_page_dump".
*
* Returns the contents of @bprm on success, NULL otherwise.
*
* This function uses kzalloc(), so caller must kfree() if this function
* didn't return NULL.
*/
static char *tomoyo_print_bprm(struct linux_binprm *bprm,
struct tomoyo_page_dump *dump)
{
static const int tomoyo_buffer_len = 4096 * 2;
char *buffer = kzalloc(tomoyo_buffer_len, GFP_NOFS);
char *cp;
char *last_start;
int len;
unsigned long pos = bprm->p;
int offset = pos % PAGE_SIZE;
int argv_count = bprm->argc;
int envp_count = bprm->envc;
bool truncated = false;
if (!buffer)
return NULL;
len = snprintf(buffer, tomoyo_buffer_len - 1, "argv[]={ ");
cp = buffer + len;
if (!argv_count) {
memmove(cp, "} envp[]={ ", 11);
cp += 11;
}
last_start = cp;
while (argv_count || envp_count) {
if (!tomoyo_dump_page(bprm, pos, dump))
goto out;
pos += PAGE_SIZE - offset;
/* Read. */
while (offset < PAGE_SIZE) {
const char *kaddr = dump->data;
const unsigned char c = kaddr[offset++];
if (cp == last_start)
*cp++ = '"';
if (cp >= buffer + tomoyo_buffer_len - 32) {
/* Reserve some room for "..." string. */
truncated = true;
} else if (c == '\\') {
*cp++ = '\\';
*cp++ = '\\';
} else if (c > ' ' && c < 127) {
*cp++ = c;
} else if (!c) {
*cp++ = '"';
*cp++ = ' ';
last_start = cp;
} else {
*cp++ = '\\';
*cp++ = (c >> 6) + '0';
*cp++ = ((c >> 3) & 7) + '0';
*cp++ = (c & 7) + '0';
}
if (c)
continue;
if (argv_count) {
if (--argv_count == 0) {
if (truncated) {
cp = last_start;
memmove(cp, "... ", 4);
cp += 4;
}
memmove(cp, "} envp[]={ ", 11);
cp += 11;
last_start = cp;
truncated = false;
}
} else if (envp_count) {
if (--envp_count == 0) {
if (truncated) {
cp = last_start;
memmove(cp, "... ", 4);
cp += 4;
}
}
}
if (!argv_count && !envp_count)
break;
}
offset = 0;
}
*cp++ = '}';
*cp = '\0';
return buffer;
out:
snprintf(buffer, tomoyo_buffer_len - 1,
"argv[]={ ... } envp[]= { ... }");
return buffer;
}
/**
* tomoyo_filetype - Get string representation of file type.
*
* @mode: Mode value for stat().
*
* Returns file type string.
*/
static inline const char *tomoyo_filetype(const umode_t mode)
{
switch (mode & S_IFMT) {
case S_IFREG:
case 0:
return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FILE];
case S_IFDIR:
return tomoyo_condition_keyword[TOMOYO_TYPE_IS_DIRECTORY];
case S_IFLNK:
return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SYMLINK];
case S_IFIFO:
return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FIFO];
case S_IFSOCK:
return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SOCKET];
case S_IFBLK:
return tomoyo_condition_keyword[TOMOYO_TYPE_IS_BLOCK_DEV];
case S_IFCHR:
return tomoyo_condition_keyword[TOMOYO_TYPE_IS_CHAR_DEV];
}
return "unknown"; /* This should not happen. */
}
/**
* tomoyo_print_header - Get header line of audit log.
*
* @r: Pointer to "struct tomoyo_request_info".
*
* Returns string representation.
*
* This function uses kmalloc(), so caller must kfree() if this function
* didn't return NULL.
*/
static char *tomoyo_print_header(struct tomoyo_request_info *r)
{
struct tomoyo_time stamp;
const pid_t gpid = task_pid_nr(current);
struct tomoyo_obj_info *obj = r->obj;
static const int tomoyo_buffer_len = 4096;
char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS);
int pos;
u8 i;
if (!buffer)
return NULL;
tomoyo_convert_time(ktime_get_real_seconds(), &stamp);
pos = snprintf(buffer, tomoyo_buffer_len - 1,
"#%04u/%02u/%02u %02u:%02u:%02u# profile=%u mode=%s "
"granted=%s (global-pid=%u) task={ pid=%u ppid=%u "
"uid=%u gid=%u euid=%u egid=%u suid=%u sgid=%u "
"fsuid=%u fsgid=%u }", stamp.year, stamp.month,
stamp.day, stamp.hour, stamp.min, stamp.sec, r->profile,
tomoyo_mode[r->mode], tomoyo_yesno(r->granted), gpid,
tomoyo_sys_getpid(), tomoyo_sys_getppid(),
from_kuid(&init_user_ns, current_uid()),
from_kgid(&init_user_ns, current_gid()),
from_kuid(&init_user_ns, current_euid()),
from_kgid(&init_user_ns, current_egid()),
from_kuid(&init_user_ns, current_suid()),
from_kgid(&init_user_ns, current_sgid()),
from_kuid(&init_user_ns, current_fsuid()),
from_kgid(&init_user_ns, current_fsgid()));
if (!obj)
goto no_obj_info;
if (!obj->validate_done) {
tomoyo_get_attributes(obj);
obj->validate_done = true;
}
for (i = 0; i < TOMOYO_MAX_PATH_STAT; i++) {
struct tomoyo_mini_stat *stat;
unsigned int dev;
umode_t mode;
if (!obj->stat_valid[i])
continue;
stat = &obj->stat[i];
dev = stat->dev;
mode = stat->mode;
if (i & 1) {
pos += snprintf(buffer + pos,
tomoyo_buffer_len - 1 - pos,
" path%u.parent={ uid=%u gid=%u "
"ino=%lu perm=0%o }", (i >> 1) + 1,
from_kuid(&init_user_ns, stat->uid),
from_kgid(&init_user_ns, stat->gid),
(unsigned long)stat->ino,
stat->mode & S_IALLUGO);
continue;
}
pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos,
" path%u={ uid=%u gid=%u ino=%lu major=%u"
" minor=%u perm=0%o type=%s", (i >> 1) + 1,
from_kuid(&init_user_ns, stat->uid),
from_kgid(&init_user_ns, stat->gid),
(unsigned long)stat->ino,
MAJOR(dev), MINOR(dev),
mode & S_IALLUGO, tomoyo_filetype(mode));
if (S_ISCHR(mode) || S_ISBLK(mode)) {
dev = stat->rdev;
pos += snprintf(buffer + pos,
tomoyo_buffer_len - 1 - pos,
" dev_major=%u dev_minor=%u",
MAJOR(dev), MINOR(dev));
}
pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos,
" }");
}
no_obj_info:
if (pos < tomoyo_buffer_len - 1)
return buffer;
kfree(buffer);
return NULL;
}
/**
* tomoyo_init_log - Allocate buffer for audit logs.
*
* @r: Pointer to "struct tomoyo_request_info".
* @len: Buffer size needed for @fmt and @args.
* @fmt: The printf()'s format string.
* @args: va_list structure for @fmt.
*
* Returns pointer to allocated memory.
*
* This function uses kzalloc(), so caller must kfree() if this function
* didn't return NULL.
*/
char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt,
va_list args)
{
char *buf = NULL;
char *bprm_info = NULL;
const char *header = NULL;
char *realpath = NULL;
const char *symlink = NULL;
int pos;
const char *domainname = r->domain->domainname->name;
header = tomoyo_print_header(r);
if (!header)
return NULL;
/* +10 is for '\n' etc. and '\0'. */
len += strlen(domainname) + strlen(header) + 10;
if (r->ee) {
struct file *file = r->ee->bprm->file;
realpath = tomoyo_realpath_from_path(&file->f_path);
bprm_info = tomoyo_print_bprm(r->ee->bprm, &r->ee->dump);
if (!realpath || !bprm_info)
goto out;
/* +80 is for " exec={ realpath=\"%s\" argc=%d envc=%d %s }" */
len += strlen(realpath) + 80 + strlen(bprm_info);
} else if (r->obj && r->obj->symlink_target) {
symlink = r->obj->symlink_target->name;
/* +18 is for " symlink.target=\"%s\"" */
len += 18 + strlen(symlink);
}
len = tomoyo_round2(len);
buf = kzalloc(len, GFP_NOFS);
if (!buf)
goto out;
len--;
pos = snprintf(buf, len, "%s", header);
if (realpath) {
struct linux_binprm *bprm = r->ee->bprm;
pos += snprintf(buf + pos, len - pos,
" exec={ realpath=\"%s\" argc=%d envc=%d %s }",
realpath, bprm->argc, bprm->envc, bprm_info);
} else if (symlink)
pos += snprintf(buf + pos, len - pos, " symlink.target=\"%s\"",
symlink);
pos += snprintf(buf + pos, len - pos, "\n%s\n", domainname);
vsnprintf(buf + pos, len - pos, fmt, args);
out:
kfree(realpath);
kfree(bprm_info);
kfree(header);
return buf;
}
/* Wait queue for /sys/kernel/security/tomoyo/audit. */
static DECLARE_WAIT_QUEUE_HEAD(tomoyo_log_wait);
/* Structure for audit log. */
struct tomoyo_log {
struct list_head list;
char *log;
int size;
};
/* The list for "struct tomoyo_log". */
static LIST_HEAD(tomoyo_log);
/* Lock for "struct list_head tomoyo_log". */
static DEFINE_SPINLOCK(tomoyo_log_lock);
/* Length of "stuct list_head tomoyo_log". */
static unsigned int tomoyo_log_count;
/**
* tomoyo_get_audit - Get audit mode.
*
* @ns: Pointer to "struct tomoyo_policy_namespace".
* @profile: Profile number.
* @index: Index number of functionality.
* @is_granted: True if granted log, false otherwise.
*
* Returns true if this request should be audited, false otherwise.
*/
static bool tomoyo_get_audit(const struct tomoyo_policy_namespace *ns,
const u8 profile, const u8 index,
const struct tomoyo_acl_info *matched_acl,
const bool is_granted)
{
u8 mode;
const u8 category = tomoyo_index2category[index] +
TOMOYO_MAX_MAC_INDEX;
struct tomoyo_profile *p;
if (!tomoyo_policy_loaded)
return false;
p = tomoyo_profile(ns, profile);
if (tomoyo_log_count >= p->pref[TOMOYO_PREF_MAX_AUDIT_LOG])
return false;
if (is_granted && matched_acl && matched_acl->cond &&
matched_acl->cond->grant_log != TOMOYO_GRANTLOG_AUTO)
return matched_acl->cond->grant_log == TOMOYO_GRANTLOG_YES;
mode = p->config[index];
if (mode == TOMOYO_CONFIG_USE_DEFAULT)
mode = p->config[category];
if (mode == TOMOYO_CONFIG_USE_DEFAULT)
mode = p->default_config;
if (is_granted)
return mode & TOMOYO_CONFIG_WANT_GRANT_LOG;
return mode & TOMOYO_CONFIG_WANT_REJECT_LOG;
}
/**
* tomoyo_write_log2 - Write an audit log.
*
* @r: Pointer to "struct tomoyo_request_info".
* @len: Buffer size needed for @fmt and @args.
* @fmt: The printf()'s format string.
* @args: va_list structure for @fmt.
*
* Returns nothing.
*/
void tomoyo_write_log2(struct tomoyo_request_info *r, int len, const char *fmt,
va_list args)
{
char *buf;
struct tomoyo_log *entry;
bool quota_exceeded = false;
if (!tomoyo_get_audit(r->domain->ns, r->profile, r->type,
r->matched_acl, r->granted))
goto out;
buf = tomoyo_init_log(r, len, fmt, args);
if (!buf)
goto out;
entry = kzalloc(sizeof(*entry), GFP_NOFS);
if (!entry) {
kfree(buf);
goto out;
}
entry->log = buf;
len = tomoyo_round2(strlen(buf) + 1);
/*
* The entry->size is used for memory quota checks.
* Don't go beyond strlen(entry->log).
*/
entry->size = len + tomoyo_round2(sizeof(*entry));
spin_lock(&tomoyo_log_lock);
if (tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT] &&
tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] + entry->size >=
tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT]) {
quota_exceeded = true;
} else {
tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] += entry->size;
list_add_tail(&entry->list, &tomoyo_log);
tomoyo_log_count++;
}
spin_unlock(&tomoyo_log_lock);
if (quota_exceeded) {
kfree(buf);
kfree(entry);
goto out;
}
wake_up(&tomoyo_log_wait);
out:
return;
}
/**
* tomoyo_write_log - Write an audit log.
*
* @r: Pointer to "struct tomoyo_request_info".
* @fmt: The printf()'s format string, followed by parameters.
*
* Returns nothing.
*/
void tomoyo_write_log(struct tomoyo_request_info *r, const char *fmt, ...)
{
va_list args;
int len;
va_start(args, fmt);
len = vsnprintf((char *) &len, 1, fmt, args) + 1;
va_end(args);
va_start(args, fmt);
tomoyo_write_log2(r, len, fmt, args);
va_end(args);
}
/**
* tomoyo_read_log - Read an audit log.
*
* @head: Pointer to "struct tomoyo_io_buffer".
*
* Returns nothing.
*/
void tomoyo_read_log(struct tomoyo_io_buffer *head)
{
struct tomoyo_log *ptr = NULL;
if (head->r.w_pos)
return;
kfree(head->read_buf);
head->read_buf = NULL;
spin_lock(&tomoyo_log_lock);
if (!list_empty(&tomoyo_log)) {
ptr = list_entry(tomoyo_log.next, typeof(*ptr), list);
list_del(&ptr->list);
tomoyo_log_count--;
tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] -= ptr->size;
}
spin_unlock(&tomoyo_log_lock);
if (ptr) {
head->read_buf = ptr->log;
head->r.w[head->r.w_pos++] = head->read_buf;
kfree(ptr);
}
}
/**
* tomoyo_poll_log - Wait for an audit log.
*
* @file: Pointer to "struct file".
* @wait: Pointer to "poll_table". Maybe NULL.
*
* Returns EPOLLIN | EPOLLRDNORM when ready to read an audit log.
*/
__poll_t tomoyo_poll_log(struct file *file, poll_table *wait)
{
if (tomoyo_log_count)
return EPOLLIN | EPOLLRDNORM;
poll_wait(file, &tomoyo_log_wait, wait);
if (tomoyo_log_count)
return EPOLLIN | EPOLLRDNORM;
return 0;
}
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