[ 078/143] ipv4: fix possible seqlock deadlock

[Willy Tarreau]

2.6.32-longterm review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Dumazet <edumazet@xxxxxxxxxx>

[ Upstream commit c9e9042994d37cbc1ee538c500e9da1bb9d1bcdf ]

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@xxxxxxxxxx>
Reported-by: Dave Jones <davej@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Willy Tarreau <w@xxxxxx>
---
 net/ipv4/datagram.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/datagram.c b/net/ipv4/datagram.c
index 5e6c5a0..30aeb26 100644
--- a/net/ipv4/datagram.c
+++ b/net/ipv4/datagram.c
@@ -52,7 +52,7 @@ int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 			       inet->sport, usin->sin_port, sk, 1);
 	if (err) {
 		if (err == -ENETUNREACH)
-			IP_INC_STATS_BH(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
+			IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
 		return err;
 	}
 
-- 
1.7.12.2.21.g234cd45.dirty



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