[PATCH 4.9 04/93] vxlan: correctly validate VXLAN ID against VXLAN_N_VID

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Matthias Schiffer <mschiffer@xxxxxxxxxxxxxxxxxxxx>


[ Upstream commit 4e37d6911f36545b286d15073f6f2222f840e81c ]

The incorrect check caused an off-by-one error: the maximum VID 0xffffff
was unusable.

Fixes: d342894c5d2f ("vxlan: virtual extensible lan")
Signed-off-by: Matthias Schiffer <mschiffer@xxxxxxxxxxxxxxxxxxxx>
Acked-by: Jiri Benc <jbenc@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/vxlan.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -2637,7 +2637,7 @@ static int vxlan_validate(struct nlattr
 
 	if (data[IFLA_VXLAN_ID]) {
 		__u32 id = nla_get_u32(data[IFLA_VXLAN_ID]);
-		if (id >= VXLAN_VID_MASK)
+		if (id >= VXLAN_N_VID)
 			return -ERANGE;
 	}