Linux Kernel CVE-2026-31443

The vulnerability exists in the dmaengine idxd (Intel Data Accelerator Engine) subsystem of the Linux kernel. The idxd driver manages Intel's data movement accelerator hardware and includes event logging functionality for error reporting. The bug occurs in error handling code that processes Function Level Reset (FLR) events - hardware-generated resets triggered by critical errors. When hardware does not support event log reporting (no allocation), the driver still attempts to restore and free the event log buffer during FLR recovery, causing a null pointer dereference or use-after-free. The affected code path involves conditional logic that fails to check whether the event log was actually allocated before attempting to access or free it. This is a resource management issue in kernel driver code with access restricted to local users with elevated privileges on affected systems.