3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ben Hutchings <ben@xxxxxxxxxxxxxxx> [ Upstream commit 6e80ac5cc992ab6256c3dae87f7e57db15e1a58c ] 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@xxxxxxxxxxxxxxx> Acked-by: Craig Gallek <kraig@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv6/xfrm6_mode_ro.c | 2 ++ net/ipv6/xfrm6_mode_transport.c | 2 ++ 2 files changed, 4 insertions(+) --- 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_s 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; --- a/net/ipv6/xfrm6_mode_transport.c +++ b/net/ipv6/xfrm6_mode_transport.c @@ -28,6 +28,8 @@ static int xfrm6_transport_output(struct 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;