Linux Kernel SCSI Xen Backend Driver Memory Leak Vulnerability

A memory leak vulnerability has been identified in the Linux kernel's Xen SCSI backend driver. The issue arises because memory allocated for the 'vscsiblk_info' structure during the 'scsiback_probe()' function is not released in the 'scsiback_remove()' function. This oversight can lead to memory leaks when the driver is removed, as well as during error handling in the 'scsiback_probe()'' function. The vulnerability affects the Linux kernel stable tree.

Impact

The vulnerability can lead to memory leaks, causing increased memory usage over time, which could potentially degrade system performance or lead to exhaustion of available memory resources.

Reproduction

The vulnerability can be reproduced by loading the Xen SCSI backend driver, which allocates memory for the 'vscsiblk_info' structure. When the driver is removed, the 'scsiback_remove()' function is called, but it fails to free the allocated memory, leading to a memory leak. This issue can also be observed when the 'scsiback_probe()' function encounters an error, as the allocated memory is not freed in that scenario either.

Remediation

The vulnerability has been addressed by modifying the 'scsiback_remove()' function to include a call to free the allocated memory for the 'vscsiblk_info' structure. Users should apply the latest patches available in the Linux kernel stable tree to mitigate this vulnerability.