3.5.7.15 -stable review patch.  If anyone has any objections, please let me 
know.

------------------

From: Oleg Nesterov <[email protected]>

commit f000cfdde5de4fc15dead5ccf524359c07eadf2b upstream.

audit_log_start() does wait_for_auditd() in a loop until
audit_backlog_wait_time passes or audit_skb_queue has a room.

If signal_pending() is true this becomes a busy-wait loop, schedule() in
TASK_INTERRUPTIBLE won't block.

Thanks to Guy for fully investigating and explaining the problem.

(akpm: that'll cause the system to lock up on a non-preemptible
uniprocessor kernel)

(Guy: "Our customer was in fact running a uniprocessor machine, and they
reported a system hang.")

Signed-off-by: Oleg Nesterov <[email protected]>
Reported-by: Guy Streeter <[email protected]>
Cc: Eric Paris <[email protected]>
Cc: Al Viro <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
[ luis: backported to 3.5: adjust context ]
Signed-off-by: Luis Henriques <[email protected]>
---
 kernel/audit.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/audit.c b/kernel/audit.c
index 1c7f2c6..5917dfe 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1167,7 +1167,7 @@ struct audit_buffer *audit_log_start(struct audit_context 
*ctx, gfp_t gfp_mask,
 
                        /* Wait for auditd to drain the queue a little */
                        DECLARE_WAITQUEUE(wait, current);
-                       set_current_state(TASK_INTERRUPTIBLE);
+                       set_current_state(TASK_UNINTERRUPTIBLE);
                        add_wait_queue(&audit_backlog_wait, &wait);
 
                        if (audit_backlog_limit &&
-- 
1.8.1.2

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