Linux Ethernet Bridging - Oct 2015 - [Bridge] [PATCH net-next] bridge: vlan: enforce no pvid flag in vlan ranges

From: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>

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 at mellanox.com>
Signed-off-by: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
---
 net/bridge/br_netlink.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index d78b4429505a..02b17b53e9a6 100644
--- a/net/bridge/br_netlink.c
+++ b/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;
 		}
 
-- 
2.4.3

From: Nikolay Aleksandrov <razor at blackwall.org>
Date: Sun, 11 Oct 2015 12:49:56 +0200
> From: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
> 
> 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 at mellanox.com>
> Signed-off-by: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
Applied, thanks.