From 801e866d6d0400e81bbda42259779cf4ba0f88a1 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 25 Aug 2016 15:33:29 +0200 Subject: [PATCH] netfilter: restart search if moved to other chain commit 95a8d19f28e6b29377a880c6264391a62e07fccc upstream. In case nf_conntrack_tuple_taken did not find a conflicting entry check that all entries in this hash slot were tested and restart in case an entry was moved to another chain. Reported-by: Eric Dumazet Fixes: ea781f197d6a ("netfilter: nf_conntrack: use SLAB_DESTROY_BY_RCU and get rid of call_rcu()") Signed-off-by: Florian Westphal Acked-by: Eric Dumazet Signed-off-by: Pablo Neira Ayuso [bwh: Backported to 3.2: - Adjust context - Use NF_CT_STAT_INC(), not the _ATOMIC variant, since we disable BHs] Signed-off-by: Ben Hutchings --- net/netfilter/nf_conntrack_core.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index c855673ceb23..69ce23fc81eb 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -550,6 +550,7 @@ nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple, * least once for the stats anyway. */ rcu_read_lock_bh(); + begin: hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) { ct = nf_ct_tuplehash_to_ctrack(h); if (ct != ignored_conntrack && @@ -561,6 +562,12 @@ nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple, } NF_CT_STAT_INC(net, searched); } + + if (get_nulls_value(n) != hash) { + NF_CT_STAT_INC(net, search_restart); + goto begin; + } + rcu_read_unlock_bh(); return 0; -- 2.39.2