From d2e381c4963663bca6f30c3b996fa4dbafe8fcb5 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Wed, 9 Jun 2021 14:17:53 +0300 Subject: [PATCH] rtnetlink: Fix regression in bridge VLAN configuration Cited commit started returning errors when notification info is not filled by the bridge driver, resulting in the following regression: # ip link add name br1 type bridge vlan_filtering 1 # bridge vlan add dev br1 vid 555 self pvid untagged RTNETLINK answers: Invalid argument As long as the bridge driver does not fill notification info for the bridge device itself, an empty notification should not be considered as an error. This is explained in commit 59ccaaaa49b5 ("bridge: dont send notification when skb->len == 0 in rtnl_bridge_notify"). Fix by removing the error and add a comment to avoid future bugs. Fixes: a8db57c1d285 ("rtnetlink: Fix missing error code in rtnl_bridge_notify()") Signed-off-by: Ido Schimmel Reviewed-by: Nikolay Aleksandrov Signed-off-by: David S. Miller --- net/core/rtnetlink.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 3e84279c4123..ec931b080156 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -4842,10 +4842,12 @@ static int rtnl_bridge_notify(struct net_device *dev) if (err < 0) goto errout; - if (!skb->len) { - err = -EINVAL; + /* Notification info is only filled for bridge ports, not the bridge + * device itself. Therefore, a zero notification length is valid and + * should not result in an error. + */ + if (!skb->len) goto errout; - } rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, GFP_ATOMIC); return 0;