ipv6: fix possible seqlock deadlock in ip6_finish_output2

IPv6 stats are 64 bits and thus are protected with a seqlock. By not
disabling bottom-half we could deadlock here if we don't disable bh and
a softirq reentrantly updates the same mib.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 59df872e2f4d62f68b583ff40218d68c5d5189df..4acdb63495dbe2484de9d278b810401e6d26fc6a 100644 (file)
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -116,8 +116,8 @@ static int ip6_finish_output2(struct sk_buff *skb)
        }
        rcu_read_unlock_bh();
 
-       IP6_INC_STATS_BH(dev_net(dst->dev),
-                        ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
+       IP6_INC_STATS(dev_net(dst->dev),
+                     ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
        kfree_skb(skb);
        return -EINVAL;
 }