From b88825de8545ad252c31543fef13cadf4de7a2bc Mon Sep 17 00:00:00 2001
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Tue, 5 Aug 2014 17:25:59 +0200
Subject: [PATCH] netfilter: nf_tables: don't update chain with unset counters
Fix possible replacement of the per-cpu chain counters by null
pointer when updating an existing chain in the commit path.
Reported-by: Matteo Croce <technoboy85@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
net/netfilter/nf_tables_api.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index c6f9d3d18ed1..9aa31f11056d 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -899,6 +899,9 @@ static struct nft_stats __percpu *nft_stats_alloc(const struct nlattr *attr)
static void nft_chain_stats_replace(struct nft_base_chain *chain,
struct nft_stats __percpu *newstats)
{
+ if (newstats == NULL)
+ return;
+
if (chain->stats) {
struct nft_stats __percpu *oldstats =
nft_dereference(chain->stats);