From: Florian Westphal <fw@strlen.de>
To: <netfilter-devel@vger.kernel.org>
Cc: lorenzo@google.com, zenczykowski@gmail.com, edumazet@google.com,
netdev@vger.kernel.org, maze@google.com,
Florian Westphal <fw@strlen.de>
Subject: [PATCH nf] netfilter: ipv6: fix oops when defragmenting locally generated fragments
Date: Tue, 23 Oct 2018 16:47:16 +0200 [thread overview]
Message-ID: <20181023144716.19746-1-fw@strlen.de> (raw)
In-Reply-To: <CANP3RGeX5=c=Lb+Pkg89zD7zQ_Z1T8oPJRCkorNCdghmofYXxg@mail.gmail.com>
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: 84379c9afe01 ("netfilter: ipv6: nf_defrag: drop skb dst before queueing")
Signed-off-by: Florian Westphal <fw@strlen.de>
---
net/ipv6/netfilter/nf_conntrack_reasm.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index 8f68a518d9db..f76bd4d15704 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -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);
--
2.18.1
next prev parent reply other threads:[~2018-10-23 23:12 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-16 4:13 crash in xt_policy due to skb_dst_drop() in nf_ct_frag6_gather() Maciej Żenczykowski
2018-10-16 8:11 ` Florian Westphal
2018-10-16 9:40 ` Maciej Żenczykowski
2018-10-16 9:41 ` Maciej Żenczykowski
2018-10-16 9:49 ` Maciej Żenczykowski
2018-10-23 14:47 ` Florian Westphal [this message]
2018-10-23 14:54 ` [PATCH nf] netfilter: ipv6: fix oops when defragmenting locally generated fragments Eric Dumazet
2018-10-23 21:04 ` Maciej Żenczykowski
2018-10-23 22:04 ` Florian Westphal
2018-10-25 8:18 ` Pablo Neira Ayuso
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