Linux Kernel Memory Leak Vulnerability in Watch Queue Management

A memory leak vulnerability has been identified in the Linux kernel's watch queue management. When a watch queue is dismantled, the associated page array is not properly freed, leading to a memory leak. This issue was introduced in a previous commit that addressed a similar problem with the allocation bitmap but overlooked the page array. The vulnerability allows for an unreferenced object to remain in memory, causing a resource leak.

Impact

Exploitation of this vulnerability leads to a memory leak, where unreferenced objects are not properly released, potentially causing resource exhaustion over time.

Reproduction

The vulnerability can be reproduced by creating a watch queue and then dismantling it. The page array associated with the watch queue will not be freed, leading to a memory leak. This can be observed by monitoring the system's memory usage, which will show an increase due to the unreferenced objects remaining in memory.