diff options
| author | Florian Westphal <fw@strlen.de> | 2018-02-19 08:10:17 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-03-18 11:18:54 +0100 |
| commit | 60962e98c38a563b22df67b3e55fd88837d53b83 (patch) | |
| tree | d376f70e157bc601144e5e21f8238856291528d0 /net | |
| parent | 280ef7b83b3220e12ee72857b35465f79670b33b (diff) | |
netfilter: ipv6: fix use-after-free Write in nf_nat_ipv6_manip_pkt
commit b078556aecd791b0e5cb3a59f4c3a14273b52121 upstream.
l4proto->manip_pkt() can cause reallocation of skb head so pointer
to the ipv6 header must be reloaded.
Reported-and-tested-by: <syzbot+10005f4292fc9cc89de7@syzkaller.appspotmail.com>
Fixes: 58a317f1061c89 ("netfilter: ipv6: add IPv6 NAT support")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv6/netfilter/nf_nat_l3proto_ipv6.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/net/ipv6/netfilter/nf_nat_l3proto_ipv6.c b/net/ipv6/netfilter/nf_nat_l3proto_ipv6.c index e0be97e636a4..322c7657165b 100644 --- a/net/ipv6/netfilter/nf_nat_l3proto_ipv6.c +++ b/net/ipv6/netfilter/nf_nat_l3proto_ipv6.c @@ -99,6 +99,10 @@ static bool nf_nat_ipv6_manip_pkt(struct sk_buff *skb, !l4proto->manip_pkt(skb, &nf_nat_l3proto_ipv6, iphdroff, hdroff, target, maniptype)) return false; + + /* must reload, offset might have changed */ + ipv6h = (void *)skb->data + iphdroff; + manip_addr: if (maniptype == NF_NAT_MANIP_SRC) ipv6h->saddr = target->src.u3.in6; |