[PATCH 3.8 36/91] ipv6: fix possible seqlock deadlock in ip6_finish_output2
Kamal Mostafa
kamal at canonical.com
Thu Jan 2 17:04:11 UTC 2014
3.8.13.15 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Hannes Frederic Sowa <hannes at stressinduktion.org>
[ Upstream commit 7f88c6b23afbd31545c676dea77ba9593a1a14bf ]
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 at gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes at stressinduktion.org>
Acked-by: Eric Dumazet <edumazet at google.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
net/ipv6/ip6_output.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index ac9f072..09cf37e 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -128,8 +128,8 @@ static int ip6_finish_output2(struct sk_buff *skb)
if (neigh)
return dst_neigh_output(dst, neigh, skb);
- 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;
}
--
1.8.3.2
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