netfilter: ipv6: fix oops when defragmenting locally generated fragments

[ Upstream commit 61792b677415b77c8db04991c22966bb8de7603e ]

Unlike ipv4 and normal ipv6 defrag, netfilter ipv6 defragmentation did
not save/restore skb->dst.

This causes oops when handling locally generated ipv6 fragments, as
output path needs a valid dst.

Reported-by: Maciej Żenczykowski <zenczykowski@gmail.com>
Fixes: 84379c9afe ("netfilter: ipv6: nf_defrag: drop skb dst before queueing")
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Florian Westphal 2018-10-23 16:47:16 +02:00 committed by Greg Kroah-Hartman
parent c2c72619cc
commit 84ed07d957

View file

@ -587,11 +587,16 @@ int nf_ct_frag6_gather(struct net *net, struct sk_buff *skb, u32 user)
*/
ret = -EINPROGRESS;
if (fq->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
fq->q.meat == fq->q.len &&
nf_ct_frag6_reasm(fq, skb, dev))
ret = 0;
else
fq->q.meat == fq->q.len) {
unsigned long orefdst = skb->_skb_refdst;
skb->_skb_refdst = 0UL;
if (nf_ct_frag6_reasm(fq, skb, dev))
ret = 0;
skb->_skb_refdst = orefdst;
} else {
skb_dst_drop(skb);
}
out_unlock:
spin_unlock_bh(&fq->q.lock);