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: ee122c79d422 ("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>
This commit is contained in:
Xin Long 2019-10-29 01:24:32 +08:00 committed by Greg Kroah-Hartman
parent af26f04e07
commit a1014da656

View File

@ -2006,8 +2006,11 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
ttl = info->key.ttl;
tos = info->key.tos;
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;
}