This is a note to let you know that I've just added the patch titled net: dsa: Avoid cross-chip syncing of VLAN filtering to the 5.17-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-dsa-avoid-cross-chip-syncing-of-vlan-filtering.patch and it can be found in the queue-5.17 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit e5e27fdd565f5366b50301afedb0d9654804cc7d Author: Tobias Waldekranz <tobias@xxxxxxxxxxxxxx> Date: Mon Jan 24 22:09:44 2022 +0100 net: dsa: Avoid cross-chip syncing of VLAN filtering [ Upstream commit 108dc8741c203e9d6ce4e973367f1bac20c7192b ] 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 <tobias@xxxxxxxxxxxxxx> Reviewed-by: Vladimir Oltean <olteanv@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/dsa/switch.c b/net/dsa/switch.c index 9f9b70d6070a..517cc83d13cc 100644 --- a/net/dsa/switch.c +++ b/net/dsa/switch.c @@ -180,9 +180,11 @@ static int dsa_switch_bridge_leave(struct dsa_switch *ds, info->sw_index, info->port, info->bridge); - err = dsa_switch_sync_vlan_filtering(ds, info); - if (err) - return err; + if (ds->dst->index == info->tree_index && ds->index == info->sw_index) { + err = dsa_switch_sync_vlan_filtering(ds, info); + if (err) + return err; + } return dsa_tag_8021q_bridge_leave(ds, info); }