From f9f02cca25acf33e5853c6b3cbb0c7146312783f Mon Sep 17 00:00:00 2001
From: Patrick McHardy <kaber@trash.net>
Date: Tue, 9 Jan 2007 14:32:41 -0800
Subject: [PATCH] [NETFILTER]: nf_conntrack_ipv6: fix crash when handling
 fragments

When IPv6 connection tracking splits up a defragmented packet into
its original fragments, the packets are taken from a list and are
passed to the network stack with skb->next still set. This causes
dev_hard_start_xmit to treat them as GSO fragments, resulting in
a use after free when connection tracking handles the next fragment.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/ipv6/netfilter/nf_conntrack_reasm.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index 37e5fca923aa1..d9c15402ba661 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -835,6 +835,8 @@ void nf_ct_frag6_output(unsigned int hooknum, struct sk_buff *skb,
 		s->nfct_reasm = skb;
 
 		s2 = s->next;
+		s->next = NULL;
+
 		NF_HOOK_THRESH(PF_INET6, hooknum, s, in, out, okfn,
 			       NF_IP6_PRI_CONNTRACK_DEFRAG + 1);
 		s = s2;
-- 
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