[PATCH] net: vrf: do not allow table id 0

Frank reported that vrf devices can be created with a table id of 0.
This breaks many of the run time table id checks and should not be
allowed. Detect this condition at create time and fail with EINVAL.

Fixes: 193125dbd8eb ("net: Introduce VRF device driver")
Reported-by: Frank Kellermann <redacted>
Signed-off-by: David Ahern <redacted>
---
 drivers/net/vrf.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index 0a067708aa39..454f907d419a 100644
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c

@@ -1252,6 +1252,8 @@ static int vrf_newlink(struct net *src_net, struct net_device *dev,
 		return -EINVAL;
 
 	vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
+	if (vrf->tb_id == RT_TABLE_UNSPEC)
+		return -EINVAL;
 
 	dev->priv_flags |= IFF_L3MDEV_MASTER;
 

-- 
2.1.4

From: David Ahern <redacted>
Date: Tue, 10 Jan 2017 15:22:25 -0800

Frank reported that vrf devices can be created with a table id of 0.
This breaks many of the run time table id checks and should not be
allowed. Detect this condition at create time and fail with EINVAL.

Fixes: 193125dbd8eb ("net: Introduce VRF device driver")
Reported-by: Frank Kellermann <redacted>
Signed-off-by: David Ahern <redacted>

Applied and queued up for -stable, thanks David.