diff options
| author | Andrew Morton <akpm@linux-foundation.org> | 2013-01-11 23:32:11 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-01-11 23:54:56 +0100 |
| commit | 829199197a430dade2519d54f5545c4a094393b8 (patch) | |
| tree | af50ca9af09b83fd2a5c76cad35bd0603eb33391 /kernel | |
| parent | audit: catch possible NULL audit buffers (diff) | |
| download | linux-829199197a430dade2519d54f5545c4a094393b8.tar.xz linux-829199197a430dade2519d54f5545c4a094393b8.zip | |
kernel/audit.c: avoid negative sleep durations
audit_log_start() performs the same jiffies comparison in two places.
If sufficient time has elapsed between the two comparisons, the second
one produces a negative sleep duration:
schedule_timeout: wrong timeout value fffffffffffffff0
Pid: 6606, comm: trinity-child1 Not tainted 3.8.0-rc1+ #43
Call Trace:
schedule_timeout+0x305/0x340
audit_log_start+0x311/0x470
audit_log_exit+0x4b/0xfb0
__audit_syscall_exit+0x25f/0x2c0
sysret_audit+0x17/0x21
Fix it by performing the comparison a single time.
Reported-by: Dave Jones <davej@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/audit.c | 36 |
1 files changed, 23 insertions, 13 deletions
diff --git a/kernel/audit.c b/kernel/audit.c index a219998aecc1..d596e5355f15 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -1101,6 +1101,23 @@ static inline void audit_get_stamp(struct audit_context *ctx, } } +/* + * Wait for auditd to drain the queue a little + */ +static void wait_for_auditd(unsigned long sleep_time) +{ + DECLARE_WAITQUEUE(wait, current); + set_current_state(TASK_INTERRUPTIBLE); + add_wait_queue(&audit_backlog_wait, &wait); + + if (audit_backlog_limit && + skb_queue_len(&audit_skb_queue) > audit_backlog_limit) + schedule_timeout(sleep_time); + + __set_current_state(TASK_RUNNING); + remove_wait_queue(&audit_backlog_wait, &wait); +} + /* Obtain an audit buffer. This routine does locking to obtain the * audit buffer, but then no locking is required for calls to * audit_log_*format. If the tsk is a task that is currently in a @@ -1146,20 +1163,13 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, while (audit_backlog_limit && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) { - if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time - && time_before(jiffies, timeout_start + audit_backlog_wait_time)) { - - /* Wait for auditd to drain the queue a little */ - DECLARE_WAITQUEUE(wait, current); - set_current_state(TASK_INTERRUPTIBLE); - add_wait_queue(&audit_backlog_wait, &wait); - - if (audit_backlog_limit && - skb_queue_len(&audit_skb_queue) > audit_backlog_limit) - schedule_timeout(timeout_start + audit_backlog_wait_time - jiffies); + if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time) { + unsigned long sleep_time; - __set_current_state(TASK_RUNNING); - remove_wait_queue(&audit_backlog_wait, &wait); + sleep_time = timeout_start + audit_backlog_wait_time - + jiffies; + if ((long)sleep_time > 0) + wait_for_auditd(sleep_time); continue; } if (audit_rate_check() && printk_ratelimit()) |