Linux Kernel Use-After-Free Vulnerability in DRM GEM Shmem Objects

A use-after-free vulnerability has been identified in the Linux kernel's Direct Rendering Manager (DRM) subsystem, specifically within the shared memory (shmem) helper. The issue arises in the 'drm_gem_shmem_mmap()' function, where an incorrect reference management in the error handling path leads to premature deallocation of the DMA buffer shared memory Graphics Execution Manager (GEM) object. This early freeing creates the potential for a use-after-free condition, which can be exploited to cause memory corruption.

Impact

Exploitation of this vulnerability leads to a use-after-free condition, allowing for memory corruption, which could be exploited to execute arbitrary code or cause a denial-of-service condition by crashing the system.