Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, =?UTF-8?q?Maciej=20=C5=BBenczykowski?= , Florian Westphal , Eric Dumazet , Pablo Neira Ayuso , Sasha Levin Subject: [PATCH 4.19 033/118] netfilter: ipv6: fix oops when defragmenting locally generated fragments Date: Mon, 26 Nov 2018 11:50:27 +0100 Message-Id: <20181126105101.307993614@linuxfoundation.org> In-Reply-To: <20181126105059.832485122@linuxfoundation.org> References: <20181126105059.832485122@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit List-ID: 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ [ 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 Fixes: 84379c9afe01 ("netfilter: ipv6: nf_defrag: drop skb dst before queueing") Signed-off-by: Florian Westphal Reviewed-by: Eric Dumazet Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- 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); -- 2.17.1