From 6948a6654ffc878fc0258b363da77e7fd775b2d9 Mon Sep 17 00:00:00 2001 From: Tobias Waldekranz Date: Mon, 24 Jan 2022 22:09:44 +0100 Subject: [PATCH 5.10 2/2] net: dsa: Avoid cross-chip syncing of VLAN filtering MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 108dc8741c203e9d6ce4e973367f1bac20c7192b upstream. Changes to VLAN filtering are not applicable to cross-chip notifications. On a system like this: .-----. .-----. .-----. | sw1 +---+ sw2 +---+ sw3 | '-1-2-' '-1-2-' '-1-2-' Before this change, upon sw1p1 leaving a bridge, a call to dsa_port_vlan_filtering would also be made to sw2p1 and sw3p1. In this scenario: .---------. .-----. .-----. | sw1 +---+ sw2 +---+ sw3 | '-1-2-3-4-' '-1-2-' '-1-2-' When sw1p4 would leave a bridge, dsa_port_vlan_filtering would be called for sw2 and sw3 with a non-existing port - leading to array out-of-bounds accesses and crashes on mv88e6xxx. Fixes: d371b7c92d19 ("net: dsa: Unset vlan_filtering when ports leave the bridge") Signed-off-by: Tobias Waldekranz Reviewed-by: Vladimir Oltean Signed-off-by: David S. Miller Signed-off-by: Marek Behún --- net/dsa/switch.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- a/net/dsa/switch.c +++ b/net/dsa/switch.c @@ -162,9 +162,11 @@ static int dsa_switch_bridge_leave(struc info->sw_index, info->port, info->br); - err = dsa_switch_sync_vlan_filtering(ds, info); - if (err) - return err; + if (dst->index == info->tree_index && ds->index == info->sw_index) { + err = dsa_switch_sync_vlan_filtering(ds, info); + if (err) + return err; + } return 0; }