From: Eric Dumazet <edumazet@google.com>
Date: Thu, 14 Nov 2013 21:37:54 +0000 (-0800)
Subject: ipv4: fix possible seqlock deadlock
X-Git-Tag: v3.13-rc1~33^2~25
X-Git-Url: http://pileus.org/git/?p=~andy%2Flinux;a=commitdiff_plain;h=c9e9042994d37cbc1ee538c500e9da1bb9d1bcdf

ipv4: fix possible seqlock deadlock

ip4_datagram_connect() being called from process context,
it should use IP_INC_STATS() instead of IP_INC_STATS_BH()
otherwise we can deadlock on 32bit arches, or get corruptions of
SNMP counters.

Fixes: 584bdf8cbdf6 ("[IPV4]: Fix "ipOutNoRoutes" counter error for TCP and UDP")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv4/datagram.c b/net/ipv4/datagram.c
index b28e863fe0a..19e36376d2a 100644
--- a/net/ipv4/datagram.c
+++ b/net/ipv4/datagram.c
@@ -57,7 +57,7 @@ int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 	if (IS_ERR(rt)) {
 		err = PTR_ERR(rt);
 		if (err == -ENETUNREACH)
-			IP_INC_STATS_BH(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
+			IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
 		goto out;
 	}