ipv4: fix possible seqlock deadlock

[ 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@google.com>
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/net/ipv4/datagram.c b/net/ipv4/datagram.c
index 5e6c5a0f3fde2ac0bea2956542260bd5d947d553..30aeb26c00005a1d6d99d2aa5a05a73fcd9c80a3 100644 (file)
--- 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;
        }