tcp: fix incorrect LOCKDROPPEDICMPS counter

[ Upstream commit b74aa930ef49a3c0d8e4c1987f89decac768fb2c ]

commit 563d34d057 (tcp: dont drop MTU reduction indications)
added an error leading to incorrect accounting of
LINUX_MIB_LOCKDROPPEDICMPS

If socket is owned by the user, we want to increment
this SNMP counter, unless the message is a
(ICMP_DEST_UNREACH,ICMP_FRAG_NEEDED) one.

Reported-by: Maciej ¯enczykowski <maze@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Maciej ¯enczykowski <maze@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index bc3cb46b21a3f3f9b08e30e4fe8357ce4f12805d..e637770e425a40080ade7a35a504b6c39bdaa930 100644 (file)
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -380,11 +380,10 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info)
         * We do take care of PMTU discovery (RFC1191) special case :
         * we can receive locally generated ICMP messages while socket is held.
         */
-       if (sock_owned_by_user(sk) &&
-           type != ICMP_DEST_UNREACH &&
-           code != ICMP_FRAG_NEEDED)
-               NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
-
+       if (sock_owned_by_user(sk)) {
+               if (!(type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED))
+                       NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
+       }
        if (sk->sk_state == TCP_CLOSE)
                goto out;