net: vrf: do not allow table id 0

[ Upstream commit 24c63bbc18e25d5d8439422aa5fd2d66390b88eb ]

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.kellermann@atos.net>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index 12b8085430e845c610b6dcee5c1ef68de26d1a20..95cf1d84478158f000c39ef177a8a44411e304f9 100644 (file)
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -1239,6 +1239,8 @@ 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;