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

[David Ahern]

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 <frank.kellerm...@atos.net>
Signed-off-by: David Ahern <d...@cumulusnetworks.com>
---
 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