Commit 967ab999 authored Jul 31, 2008 by Pavel Emelyanov Committed by David S. Miller Jul 31, 2008

netfilter: xt_hashlimit: fix race between htable_destroy and htable_gc



Deleting a timer with del_timer doesn't guarantee, that the
timer function is not running at the moment of deletion. Thus
in the xt_hashlimit case we can get into a ticklish situation
when the htable_gc rearms the timer back and we'll actually
delete an entry with a pending timer.

Fix it with using del_timer_sync().

AFAIK del_timer_sync checks for the timer to be pending by
itself, so I remove the check.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent a8ddc916

net/netfilter/xt_hashlimit.c

+1 −3

Original line number	Diff line number	Diff line
		@@ -367,9 +367,7 @@ static void htable_gc(unsigned long htlong)

		static void htable_destroy(struct xt_hashlimit_htable *hinfo)
		{
		/* remove timer, if it is pending */
		if (timer_pending(&hinfo->timer))
		del_timer(&hinfo->timer);
		del_timer_sync(&hinfo->timer);

		/* remove proc entry */
		remove_proc_entry(hinfo->pde->name,