net: dsa: Avoid cross-chip syncing of VLAN filtering
authorTobias Waldekranz <tobias@waldekranz.com>
Mon, 24 Jan 2022 21:09:44 +0000 (22:09 +0100)
committerDavid S. Miller <davem@davemloft.net>
Tue, 25 Jan 2022 11:45:39 +0000 (11:45 +0000)
commit108dc8741c203e9d6ce4e973367f1bac20c7192b
treec5a76c79c11f457ac3822fcf5b7afdf7a558da68
parent381a730182f1d174e1950cd4e63e885b1c302051
net: dsa: Avoid cross-chip syncing of VLAN filtering

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@waldekranz.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/dsa/switch.c