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authorAndrew Morton <akpm@linux-foundation.org>2013-01-11 14:32:11 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-01-11 14:54:56 -0800
commit829199197a430dade2519d54f5545c4a094393b8 (patch)
treeaf50ca9af09b83fd2a5c76cad35bd0603eb33391 /kernel/audit.c
parent0644ec0cc8a33fb654e348897ad7684e22a4b5d8 (diff)
downloadlinaro-lsk-829199197a430dade2519d54f5545c4a094393b8.tar.gz
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/audit.c')
-rw-r--r--kernel/audit.c36
1 files changed, 23 insertions, 13 deletions
diff --git a/kernel/audit.c b/kernel/audit.c
index a219998aecc..d596e5355f1 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())