Linux Kernel Memory Block Reference Leak Vulnerability in Poison Accounting

A vulnerability exists in the Linux kernel's memory management system, specifically within the poison accounting feature. The issue arises in the 'drivers/base/memory' component, where the functions 'memblk_nr_poison_inc()' and 'memblk_nr_poison_sub()' improperly handle references to memory block devices. These functions look up memory blocks by their IDs, acquiring a reference to the corresponding device. However, they fail to release this reference after use, leading to a memory leak with each successful lookup. The vulnerability affects several versions of the Linux kernel.

Impact

The vulnerability causes a memory leak by failing to release device references after they are no longer needed, which could potentially lead to increased memory usage and degradation of system performance over time.

Reproduction

The vulnerability can be reproduced by invoking the 'memblk_nr_poison_inc()' and 'memblk_nr_poison_sub()' functions with valid page frame numbers. These functions will leak device references for each memory block accessed, without releasing the references, thereby creating 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.