Commit eadf52cf authored Oct 29, 2019 by Xin Long Committed by David S. Miller Oct 29, 2019

vxlan: check tun_info options_len properly



This patch is to improve the tun_info options_len by dropping
the skb when TUNNEL_VXLAN_OPT is set but options_len is less
than vxlan_metadata. This can void a potential out-of-bounds
access on ip_tun_info.

Fixes: ee122c79 ("vxlan: Flow based tunneling")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 2eb8d6d2

drivers/net/vxlan.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -2487,9 +2487,11 @@ static void vxlan_xmit_one(struct sk_buff skb, struct net_device dev,
		vni = tunnel_id_to_key32(info->key.tun_id);
		ifindex = 0;
		dst_cache = &info->dst_cache;
		if (info->options_len &&
		info->key.tun_flags & TUNNEL_VXLAN_OPT)
		if (info->key.tun_flags & TUNNEL_VXLAN_OPT) {
		if (info->options_len < sizeof(*md))
		goto drop;
		md = ip_tunnel_info_opts(info);
		}
		ttl = info->key.ttl;
		tos = info->key.tos;
		label = info->key.label;