Commit 0ee544c2 authored Oct 29, 2019 by Xin Long Committed by Greg Kroah-Hartman Nov 10, 2019

vxlan: check tun_info options_len properly



[ Upstream commit eadf52cf1852196a1363044dcda22fa5d7f296f7 ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 28f36653

drivers/net/vxlan.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -2049,8 +2049,11 @@ static void vxlan_xmit_one(struct sk_buff skb, struct net_device dev,
		label = info->key.label;
		udp_sum = !!(info->key.tun_flags & TUNNEL_CSUM);

		if (info->options_len)
		if (info->options_len) {
		if (info->options_len < sizeof(*md))
		goto drop;
		md = ip_tunnel_info_opts(info);
		}
		} else {
		md->gbp = skb->mark;
		}