CVE-2026-63951

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A use-after-free issue exists in the zram writeback endio function. A race condition occurs between the bio completion handler (zram writeback endio) and the writeback task. Specifically, wake up() is called on &wb ctl->done wait after the wb ctl->done lock is released. This allows the writeback task to detect that num inflight has reached 0, return, and free the wb ctl structure before the wake up() call is executed, leading to a NULL pointer dereference and a system crash.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.