net: dsa: Avoid cross-chip syncing of VLAN filtering

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: 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.

References

• https://git.kernel.org/stable/c/e1f2a4dd8d433eec393d09273a78a3d3551339cf
• https://git.kernel.org/stable/c/108dc8741c203e9d6ce4e973367f1bac20c7192b