ipv6: xfrm: Handle errors reported by xfrm6_find_1stfragopt()

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>
Gbp-Pq: Topic bugfix/all
Gbp-Pq: Name ipv6-xfrm-handle-errors-reported-by-xfrm6_find_1stfr.patch

diff --git a/net/ipv6/xfrm6_mode_ro.c b/net/ipv6/xfrm6_mode_ro.c
index 0e015906f9ca91e11d3e9e124c532c6a7cb04c5d..07d36573f50b9451e4c2bfee331ac2c023791a7a 100644 (file)
--- a/net/ipv6/xfrm6_mode_ro.c
+++ b/net/ipv6/xfrm6_mode_ro.c
@@ -47,6 +47,8 @@ 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 4e344105b3fddeacfc79ca7492b62f223de2c02e..1d3bbe6e11834737e9091620c655d3b718ad8291 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;