From afce615aaabfbaad02550e75c0bec106dafa1adf Mon Sep 17 00:00:00 2001 From: Stefano Brivio Date: Mon, 24 Jul 2017 23:14:28 +0200 Subject: [PATCH] ipv6: Don't increase IPSTATS_MIB_FRAGFAILS twice in ip6_fragment() RFC 2465 defines ipv6IfStatsOutFragFails as: "The number of IPv6 datagrams that have been discarded because they needed to be fragmented at this output interface but could not be." The existing implementation, instead, would increase the counter twice in case we fail to allocate room for single fragments: once for the fragment, once for the datagram. This didn't look intentional though. In one of the two affected affected failure paths, the double increase was simply a result of a new 'goto fail' statement, introduced to avoid a skb leak. The other path appears to be affected since at least 2.6.12-rc2. Reported-by: Sabrina Dubroca Fixes: 1d325d217c7f ("ipv6: ip6_fragment: fix headroom tests and skb leak") Signed-off-by: Stefano Brivio Signed-off-by: David S. Miller --- net/ipv6/ip6_output.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 1422d6c08377..162efba0d0cd 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -673,8 +673,6 @@ int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, *prevhdr = NEXTHDR_FRAGMENT; tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC); if (!tmp_hdr) { - IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), - IPSTATS_MIB_FRAGFAILS); err = -ENOMEM; goto fail; } @@ -789,8 +787,6 @@ slow_path: frag = alloc_skb(len + hlen + sizeof(struct frag_hdr) + hroom + troom, GFP_ATOMIC); if (!frag) { - IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), - IPSTATS_MIB_FRAGFAILS); err = -ENOMEM; goto fail; } -- 2.20.1