From patchwork Tue Mar 6 11:22:55 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [6/6] netfilter: nf_conntrack: fix early_drop with reliable event delivery From: Pablo Neira X-Patchwork-Id: 144921 Message-Id: <1331032975-5303-7-git-send-email-pablo@netfilter.org> To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org Date: Tue, 6 Mar 2012 12:22:55 +0100 From: Pablo Neira Ayuso If reliable event delivery is enabled and ctnetlink fails to deliver the destroy event in early_drop, the conntrack subsystem cannot drop any the candidate flow that was planned to be evicted. Reported-by: Kerin Millar Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_core.c | 8 ++++++-- 1 files changed, 6 insertions(+), 2 deletions(-) diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index ed86a3b..fa4b82c 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -635,8 +635,12 @@ static noinline int early_drop(struct net *net, unsigned int hash) if (del_timer(&ct->timeout)) { death_by_timeout((unsigned long)ct); - dropped = 1; - NF_CT_STAT_INC_ATOMIC(net, early_drop); + /* Check if we indeed killed this entry. Reliable event + delivery may have inserted it into the dying list. */ + if (test_bit(IPS_DYING_BIT, &ct->status)) { + dropped = 1; + NF_CT_STAT_INC_ATOMIC(net, early_drop); + } } nf_ct_put(ct); return dropped;