On 3/8/21 9:07 AM, Willem de Bruijn wrote: >> diff --git a/net/mpls/mpls_gso.c b/net/mpls/mpls_gso.c >> index b1690149b6fa..cc1b6457fc93 100644 >> --- a/net/mpls/mpls_gso.c >> +++ b/net/mpls/mpls_gso.c >> @@ -27,7 +27,7 @@ static struct sk_buff *mpls_gso_segment(struct sk_buff >> *skb, >> >> skb_reset_network_header(skb); >> mpls_hlen = skb_inner_network_header(skb) - skb_network_header(skb); >> - if (unlikely(!pskb_may_pull(skb, mpls_hlen))) >> + if (unlikely(!mpls_hlen || !pskb_may_pull(skb, mpls_hlen))) >> goto out; > > Good cathc. Besides length zero, this can be more strict: a label is > 4B, so mpls_hlen needs to be >= 4B. > > Perhaps even aligned to 4B, too, but not if there may be other encap on top. > > Unfortunately there is no struct or type definition that we can use a > sizeof instead of open coding the raw constant. >
MPLS_HLEN can be used here.
