From eccc73a6b2cb6c04bfbc40a0769f3c428dfba232 Mon Sep 17 00:00:00 2001 From: Stefano Brivio Date: Tue, 11 Jun 2019 00:27:06 +0200 Subject: geneve: Don't assume linear buffers in error handler In commit a07966447f39 ("geneve: 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 GENEVE header with udp_hdr(), so we also need to sum skb_transport_header() here. Reported-by: Guillaume Nault Fixes: a07966447f39 ("geneve: ICMP error lookup handler") Signed-off-by: Stefano Brivio Signed-off-by: David S. Miller --- drivers/net/geneve.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/net/geneve.c') diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c index 98d1a45c0606..25770122c219 100644 --- a/drivers/net/geneve.c +++ b/drivers/net/geneve.c @@ -395,7 +395,7 @@ static int geneve_udp_encap_err_lookup(struct sock *sk, struct sk_buff *skb) u8 zero_vni[3] = { 0 }; u8 *vni = zero_vni; - if (skb->len < GENEVE_BASE_HLEN) + if (!pskb_may_pull(skb, skb_transport_offset(skb) + GENEVE_BASE_HLEN)) return -EINVAL; geneveh = geneve_hdr(skb); -- cgit v1.2.3-59-g8ed1b