From fbe2454a0d10bdbf27680d4bfc93cf0293bc6a6e Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Sat, 24 Mar 2007 21:22:33 +0100 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 Signed-off-by: Adrian Bunk --- 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 84ef9a13108d..cd20caa0039d 100644 --- a/net/ipv6/netfilter/nf_conntrack_reasm.c +++ b/net/ipv6/netfilter/nf_conntrack_reasm.c @@ -840,6 +840,8 @@ 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;