From: Stefano Brivio sbrivio@redhat.com
[ Upstream commit 8399a6930d12f5965230f4ff058228a4cc80c0b9 ]
In commit c3a43b9fec8a ("vxlan: ICMP error lookup handler") I wrongly assumed buffers from icmp_socket_deliver() would be linear. This is not the case: icmp_socket_deliver() only guarantees we have 8 bytes of linear data.
Eric fixed this same issue for fou and fou6 in commits 26fc181e6cac ("fou, fou6: do not assume linear skbs") and 5355ed6388e2 ("fou, fou6: avoid uninit-value in gue_err() and gue6_err()").
Use pskb_may_pull() instead of checking skb->len, and take into account the fact we later access the VXLAN header with udp_hdr(), so we also need to sum skb_transport_header() here.
Reported-by: Guillaume Nault gnault@redhat.com Fixes: c3a43b9fec8a ("vxlan: ICMP error lookup handler") Signed-off-by: Stefano Brivio sbrivio@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/vxlan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -1765,7 +1765,7 @@ static int vxlan_err_lookup(struct sock struct vxlanhdr *hdr; __be32 vni;
- if (skb->len < VXLAN_HLEN) + if (!pskb_may_pull(skb, skb_transport_offset(skb) + VXLAN_HLEN)) return -EINVAL;
hdr = vxlan_hdr(skb);