From 4d839b14d2091a224a6d0a6fa1cffa58fc00d8a7 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 12 Jun 2013 14:04:46 -0700 Subject: [PATCH] audit: wait_for_auditd() should use TASK_UNINTERRUPTIBLE 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 Reported-by: Guy Streeter Cc: Eric Paris Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds [bwh: Backported to 3.2: adjust context, indentation] Signed-off-by: Ben Hutchings --- kernel/audit.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/audit.c b/kernel/audit.c index 09fae2677a45..d4bc594acbef 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 && -- 2.39.2