CVE-2026-31566 addresses a use-after-free vulnerability in the Linux kernel's AMD GPU driver, specifically in the amdgpu_amdkfd_submit_ib() function. The function submits a GPU job and obtains a fence from amdgpu_ib_schedule(), which is used to wait for job completion. The original code called dma_fence_put() to release the fence reference before calling dma_fence_wait(). If dma_fence_put() released the last reference, the fence could be freed before dma_fence_wait() was called, causing a use-after-free. The fix ensures that dma_fence_wait() is called before releasing the fence reference, preventing premature freeing of the fence object. This vulnerability affects multiple Linux kernel versions prior to 6.8.0-1064.72 and related variants. The issue is resolved in updated kernel releases, and users are advised to update and reboot their systems.

The vulnerability can lead to a use-after-free condition in the AMD GPU driver, which may cause system instability, crashes, or potentially allow an attacker with local privileges to execute arbitrary code or escalate privileges. The CVSS 3.1 score of 7.8 (High) reflects the significant confidentiality, integrity, and availability impacts if exploited. However, there are no known exploits in the wild at this time.

An official patch is available and included in Linux kernel updates starting from version 6.8.0-1064.72 and related builds. Users should apply the latest kernel updates provided by their Linux distribution and reboot their systems to ensure the fix is active. Due to an ABI change, recompilation and reinstallation of third-party kernel modules may be required after updating. No additional mitigations are specified beyond applying the official fix.