ipv6: xfrm: Handle errors reported by xfrm6_find_1stfragopt()

commit 6e80ac5cc992ab6256c3dae87f7e57db15e1a58c upstream.

xfrm6_find_1stfragopt() may now return an error code and we must
not treat it as a length.

Fixes: 2423496af35d ("ipv6: Prevent overrun when parsing v6 header options")
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Acked-by: Craig Gallek <kraig@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/xfrm6_mode_ro.c b/net/ipv6/xfrm6_mode_ro.c
index 63d5d49..bc75be1 100644 (file)
--- a/net/ipv6/xfrm6_mode_ro.c
+++ b/net/ipv6/xfrm6_mode_ro.c
@@ -48,6 +48,8 @@ static int xfrm6_ro_output(struct xfrm_state *x, struct sk_buff *skb)
        iph = ipv6_hdr(skb);
 
        hdr_len = x->type->hdr_offset(x, skb, &prevhdr);
+       if (hdr_len < 0)
+               return hdr_len;
        skb_set_mac_header(skb, (prevhdr - x->props.header_len) - skb->data);
        skb_set_network_header(skb, -x->props.header_len);
        skb->transport_header = skb->network_header + hdr_len;

diff --git a/net/ipv6/xfrm6_mode_transport.c b/net/ipv6/xfrm6_mode_transport.c
index 4e34410..1d3bbe6 100644 (file)
--- a/net/ipv6/xfrm6_mode_transport.c
+++ b/net/ipv6/xfrm6_mode_transport.c
@@ -28,6 +28,8 @@ static int xfrm6_transport_output(struct xfrm_state *x, struct sk_buff *skb)
        iph = ipv6_hdr(skb);
 
        hdr_len = x->type->hdr_offset(x, skb, &prevhdr);
+       if (hdr_len < 0)
+               return hdr_len;
        skb_set_mac_header(skb, (prevhdr - x->props.header_len) - skb->data);
        skb_set_network_header(skb, -x->props.header_len);
        skb->transport_header = skb->network_header + hdr_len;