Linux Kernel Memory Leak Vulnerability in Traffic Control Indexing

A memory leak vulnerability has been identified in the Linux kernel's traffic control indexing feature. This issue arises in the 'tcindex_set_parms' function, where the kernel allocates new filter results without properly deallocating the previous ones, leading to a memory leak. The problem occurs when the 'old_r' variable is retrieved from the 'p->perfect' property. While the kernel correctly clears the old filter result, it fails to destroy the associated 'tcf_exts' structure', which is necessary to prevent the memory leak. The vulnerability affects several versions of the Linux kernel.

Impact

Exploitation of this vulnerability leads to a memory leak, where allocated memory is not properly released, causing increased memory usage and potential degradation of system performance over time.

Reproduction

The vulnerability can be reproduced by using the 'tcindex_change' function to modify an existing filter. This process will trigger the memory leak if 'old_r' is retrieved from 'p->perfect', as the kernel will allocate new filter results and clear the old ones without destroying the 'tcf_exts' structure', which causes the 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.