bridge: vlan: enforce no pvid flag in vlan ranges

Currently it's possible for someone to send a vlan range to the kernel
with the pvid flag set which will result in the pvid bouncing from a
vlan to vlan and isn't correct, it also introduces problems for hardware
where it doesn't make sense having more than 1 pvid. iproute2 already
enforces this, so let's enforce it on kernel-side as well.

Reported-by: Elad Raz <eladr@mellanox.com>
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_netlink.c

@@ -524,6 +524,9 @@ static int br_afspec(struct net_bridge *br,
 			if (vinfo_start)
 				return -EINVAL;
 			vinfo_start = vinfo;
+			/* don't allow range of pvids */
+			if (vinfo_start->flags & BRIDGE_VLAN_INFO_PVID)
+				return -EINVAL;
 			continue;
 		}