From mboxrd@z Thu Jan 1 00:00:00 1970 From: pablo@netfilter.org Subject: [PATCH 2/2] netfilter: nf_ct_ecache: fix crash with multiple containers, one shutting down Date: Fri, 6 Jul 2012 13:39:39 +0200 Message-ID: <1341574779-3373-3-git-send-email-pablo@netfilter.org> References: <1341574779-3373-1-git-send-email-pablo@netfilter.org> Cc: davem@davemloft.net, netdev@vger.kernel.org To: netfilter-devel@vger.kernel.org Return-path: Received: from mail.us.es ([193.147.175.20]:49399 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933576Ab2GFLkl (ORCPT ); Fri, 6 Jul 2012 07:40:41 -0400 In-Reply-To: <1341574779-3373-1-git-send-email-pablo@netfilter.org> Sender: netfilter-devel-owner@vger.kernel.org List-ID: From: Pablo Neira Ayuso Hans reports that he's still hitting: BUG: unable to handle kernel NULL pointer dereference at 000000000000027c IP: [] netlink_has_listeners+0xb/0x60 PGD 0 Oops: 0000 [#3] PREEMPT SMP CPU 0 It happens when adding a number of containers with do: nfct_query(h, NFCT_Q_CREATE, ct); and most likely one namespace shuts down. this problem was supposed to be fixed by: 70e9942 netfilter: nf_conntrack: make event callback registration per-netns Still, it was missing one rcu_access_pointer to check if the callback is set or not. Reported-by: Hans Schillstrom Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_conntrack_ecache.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/net/netfilter/nf_conntrack_ecache.h b/include/net/netfilter/nf_conntrack_ecache.h index a88fb69..e1ce104 100644 --- a/include/net/netfilter/nf_conntrack_ecache.h +++ b/include/net/netfilter/nf_conntrack_ecache.h @@ -78,7 +78,7 @@ nf_conntrack_event_cache(enum ip_conntrack_events event, struct nf_conn *ct) struct net *net = nf_ct_net(ct); struct nf_conntrack_ecache *e; - if (net->ct.nf_conntrack_event_cb == NULL) + if (!rcu_access_pointer(net->ct.nf_conntrack_event_cb)) return; e = nf_ct_ecache_find(ct); -- 1.7.10