Linux Kernel DMA Engine Event Log Memory Leak Vulnerability

A vulnerability in the Linux kernel's DMA engine component for Intel's Integrated Accelerator (IDX) can lead to a memory leak in the event log during the device removal process. When a device is removed, it is reset, and its configuration registers return to default values. This reset can occur before the driver has a chance to properly deallocate memory for the event log, especially if the event log support was not enabled. The vulnerability arises because the driver incorrectly checks for event log support instead of verifying if the event log pointer is valid, which is only allocated when the hardware capability is available.

Impact

The vulnerability can cause a memory leak by failing to properly deallocate the event log memory, potentially leading to increased memory usage and degradation of system performance over time.

Reproduction

To reproduce this vulnerability, remove a device that uses the Intel IDX DMA engine. During the removal process, the device will reset, clearing the configuration registers. If the event log support was not enabled prior to the reset, the driver will not properly deallocate the event log memory, leading to a memory leak.

Remediation

The vulnerability has been addressed in the Linux kernel. Users should upgrade to the latest version where this issue has been fixed.