CVE-2022-49134

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

mlxsw: spectrum: Guard against invalid local ports

When processing events generated by the device's firmware, the driver protects itself from events reported for non-existent local ports, but not for the CPU port (local port 0), which exists, but does not have all the fields as any local port.

This can result in a NULL pointer dereference when trying access 'struct mlxsw_sp_port' fields which are not initialized for CPU port.

Commit 63b08b1f6834 ("mlxsw: spectrum: Protect driver from buggy firmware") already handled such issue by bailing early when processing a PUDE event reported for the CPU port.

Generalize the approach by moving the check to a common function and making use of it in all relevant places.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.