diff mbox series

[net-next,4/6] vxlan: check tun_info options_len properly

Message ID 7d552d01b82edf9523288030dc03f467aee92912.1568617721.git.lucien.xin@gmail.com
State Deferred
Delegated to: David Miller
Headers show
Series net: add support for ip_tun_info options setting | expand

Commit Message

Xin Long Sept. 16, 2019, 7:10 a.m. UTC 
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.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
 drivers/net/vxlan.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 3d9bcc9..e0787286 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -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;