Linux Kernel QRTR XArray Memory Leak Vulnerability

A memory leak vulnerability has been addressed in the Linux kernel's QRTR (Queuing Radio Transmission Protocol) implementation. The issue arose from the use of a deprecated radix tree API for managing transmission flow control, which led to orphaned internal nodes that were not properly reclaimed. This memory leak occurred because the radix tree only visited slots containing leaf values, leaving linked internal nodes unaccounted for. The vulnerability affected several versions of the Linux kernel.

Impact

The vulnerability could lead to a memory leak, causing increased memory usage over time and potentially leading to a denial-of-service condition.

Reproduction

The vulnerability can be reproduced by registering a QRTR endpoint and initiating outgoing flow control, which will create entries in the radix tree. Simulating a failure in the flow control process will leave internal nodes orphaned and unreclaimed, causing a memory leak.

Remediation

The vulnerability has been fixed by migrating the transmission flow management from the deprecated radix tree to the xarray API, which properly handles the cleanup of internal nodes. Users should update to the latest version of the Linux kernel where this fix has been applied.