| From | Kamal Mostafa <> | Subject | [PATCH 76/84] audit: wait_for_auditd() should use TASK_UNINTERRUPTIBLE | Date | Mon, 17 Jun 2013 10:31:20 -0700 |
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3.8.13.3 -stable review patch. If anyone has any objections, please let me know.
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From: Oleg Nesterov <oleg@redhat.com>
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 <oleg@redhat.com> Reported-by: Guy Streeter <streeter@redhat.com> Cc: Eric Paris <eparis@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- kernel/audit.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/audit.c b/kernel/audit.c index d596e53..8a667f10 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -1107,7 +1107,7 @@ static inline void audit_get_stamp(struct audit_context *ctx, static void wait_for_auditd(unsigned long sleep_time) { 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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