Linux Kernel Prestera Module IPv4 Route Handling Vulnerability

A vulnerability in the Linux kernel's Marvell Prestera networking module affects the handling of IPv4 routes that reference a nexthop by its ID. The issue arises because the route management functions do not properly accommodate the separate storage of nexthop IDs, leading to warnings and incorrect route processing. This vulnerability is present in Linux kernel version 6.4.5.

Impact

The vulnerability causes warnings during route management and prevents proper offloading of IPv4 routes that use nexthop IDs, which could disrupt network performance or routing efficiency.

Reproduction

To reproduce the issue, bring up a network interface and assign it an IP address. Then, add a nexthop associated with that interface using a specific ID. Finally, attempt to add a route that references the nexthop by its ID. This sequence will trigger warnings about the improper handling of the route, indicating the presence of the vulnerability.

Remediation

The vulnerability has been addressed in the official Linux kernel repository. Users should upgrade to the latest version.