From: Patrick McHardy Date: Wed, 10 Jan 2007 07:04:47 +0000 (+0100) Subject: [PATCH] NETFILTER: nf_conntrack_ipv6: fix crash when handling fragments X-Git-Tag: v2.6.19.3~53 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c1e8b113af91786cba47b948dd470d8381972175;p=thirdparty%2Fkernel%2Fstable.git [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: Chris Wright --- diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c index bf93c1ea6be9b..7745caff8c3bd 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;