| Date | Mon, 12 May 2014 02:33:29 +0200 | From | Willy Tarreau <> | Subject | [ 089/143] ipv6: fix possible seqlock deadlock in ip6_finish_output2 |
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2.6.32-longterm review patch. If anyone has any objections, please let me know.
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From: Hannes Frederic Sowa <hannes@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@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> Signed-off-by: Willy Tarreau <w@1wt.eu> --- 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 bb63ffc..6ff4d07 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -91,8 +91,8 @@ static int ip6_output_finish(struct sk_buff *skb) else if (dst->neighbour) return dst->neighbour->output(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; -- 1.7.12.2.21.g234cd45.dirty
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