[PATCH 4.14 017/140] netfilter: ipv6: fix use-after-free Write in nf_nat_ipv6_manip_pkt

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

--

From: Florian Westphal 

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: 
Fixes: 58a317f1061c89 ("netfilter: ipv6: add IPv6 NAT support")
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman 

---
 net/ipv6/netfilter/nf_nat_l3proto_ipv6.c |4 
 1 file changed, 4 insertions(+)

--- 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
!l4proto->manip_pkt(skb, _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;

[PATCH 4.14 017/140] netfilter: ipv6: fix use-after-free Write in nf_nat_ipv6_manip_pkt

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

--

From: Florian Westphal 

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: 
Fixes: 58a317f1061c89 ("netfilter: ipv6: add IPv6 NAT support")
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman 

---
 net/ipv6/netfilter/nf_nat_l3proto_ipv6.c |4 
 1 file changed, 4 insertions(+)

--- 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
!l4proto->manip_pkt(skb, _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;