Linux Kernel Memory Leak Vulnerability in Key Management

A memory leak vulnerability has been identified in the Linux kernel's key management subsystem. The issue arises in the 'watch_queue' handling, where the 'watch' object is not properly freed after use. This oversight can lead to unreferenced objects remaining in memory, as indicated by reports from the kernel's memory leak detection mechanism. The vulnerability has been addressed by ensuring the missing memory deallocation is performed.

Impact

Exploitation of this vulnerability leads to a memory leak, where allocated memory is not properly released, causing unreferenced objects to persist and potentially leading to increased memory usage over time.

Reproduction

The vulnerability can be reproduced by using the 'keyctl' system call to watch a key. This action allocates memory for the watch object, which is then not freed, creating a memory leak. The 'kmemleak' feature can be used to detect the resulting unreferenced object, confirming the memory leak.