From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dan Carpenter <dan.carpenter@oracle.com>
Subject: [patch] netfilter: prevent harmless integer overflow
Date: Tue, 18 Jun 2013 10:46:03 +0300
Message-ID: <20130618074603.GF12329@elgon.mountain>
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Cc: coreteam@netfilter.org, netdev@vger.kernel.org,
	bridge@lists.linux-foundation.org, kernel-janitors@vger.kernel.org,
	"David S. Miller" <davem@davemloft.net>,
	Stephen Hemminger <stephen@networkplumber.org>,
	netfilter@vger.kernel.org, netfilter-devel@vger.kernel.org,
	Patrick McHardy <kaber@trash.net>, Pablo Neira Ayuso <pablo@netfilter.org>
To: Bart De Schuymer <bart.de.schuymer@pandora.be>
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This overflow is harmless because a few lines later we check:

	if (num_counters != t->private->nentries) {

But it still upsets the static checkers.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index 3d110c4..141350e 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -1278,6 +1278,8 @@ static int do_update_counters(struct net *net, const char *name,
 
 	if (num_counters == 0)
 		return -EINVAL;
+	if (num_counters > INT_MAX / sizeof(*tmp))
+		return -ENOMEM;
 
 	tmp = vmalloc(num_counters * sizeof(*tmp));
 	if (!tmp)