A bug in the Linux kernel’s io_uring subsystem causes a task that is waiting for completion events to enter an endless kernel loop. The spin prevents the task from being terminated, even with SIGKILL, which can stall progress of that process and degrade overall system responsiveness. The flaw can lead to a denial of service condition by exhausting scheduling resources or blocking critical paths.

The vulnerability affects Linux kernel implementations that expose the io_uring/wait subsystem. Specific kernel versions are not enumerated in the advisory, but any build that includes the affected code path – particularly those compiled with support for the io_uring interface – is potentially impacted.

The flaw is local and requires an application that uses io_uring with the IORING_SETUP_CQE_MIXED flag and a multithreaded or full‑ring event wait scenario to trigger. No remote or network trigger is required. The exploit is observable only through controlled use of io_uring; once triggered, the kernel task cannot be preempted. The EPSS score is unavailable, and the vulnerability is not listed in the CISA KEV catalog, but the potential for system‑wide disruption makes it a high‑concern DoS vector.