[PATCH 4.11 55/84] xfrm6: Fix IPv6 payload_len in xfrm6_transport_finish

From: Greg Kroah-Hartman
Date: Mon Jul 03 2017 - 09:57:44 EST

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


From: Yossi Kuperman <yossiku@xxxxxxxxxxxx>

commit 7c88e21aefcf86fb41b48b2e04528db5a30fbe18 upstream.

IPv6 payload length indicates the size of the payload, including any
extension headers.

In xfrm6_transport_finish, ipv6_hdr(skb)->payload_len is set to the
payload size only, regardless of the presence of any extension headers.
After ESP GRO transport mode decapsulation, ipv6_rcv trims the packet
according to the wrong payload_len, thus corrupting the packet.

Set payload_len to account for extension headers as well.

Fixes: 7785bba299a8 ("esp: Add a software GRO codepath")
Signed-off-by: Yossi Kuperman <yossiku@xxxxxxxxxxxx>
Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

net/ipv6/xfrm6_input.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/ipv6/xfrm6_input.c
+++ b/net/ipv6/xfrm6_input.c
@@ -43,8 +43,8 @@ int xfrm6_transport_finish(struct sk_buf
return 1;

- ipv6_hdr(skb)->payload_len = htons(skb->len);
__skb_push(skb, skb->data - skb_network_header(skb));
+ ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));

if (xo && (xo->flags & XFRM_GRO)) {