From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Emelyanov Subject: [PATCH] xt_hashlimit: fix race between htable_destroy and htable_gc Date: Thu, 24 Jul 2008 01:51:23 +0400 Message-ID: <4887A7DB.4030305@openvz.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Linux Netdev List , Netfilter Development Mailinglist To: David Miller , Patrick McHardy Return-path: Sender: netfilter-devel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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 --- diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c index 6809af5..d9418a2 100644 --- a/net/netfilter/xt_hashlimit.c +++ b/net/netfilter/xt_hashlimit.c @@ -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,