Linux Kernel VLAN Filtering Vulnerability in DSA Switches Leading to Out-of-Bounds Access

A vulnerability in the Linux kernel's handling of VLAN filtering across DSA (Distributed Switch Architecture) switches has been addressed. The issue arose when changes to VLAN filtering were incorrectly synchronized across chips, leading to potential out-of-bounds accesses and crashes on certain switch chips, such as the mv88e6xxx. This vulnerability occurred because, when a port on one switch left a bridge, the VLAN filtering change was also applied to corresponding ports on other switches, regardless of whether those ports existed. This mismatch could cause the system to access invalid memory, resulting in a crash.

Impact

The vulnerability could be exploited to cause out-of-bounds memory access, leading to a crash of the system or potentially allowing for arbitrary code execution.