CVE-2024-56762

[REJECTED CVE] A use-after-free (UAF) vulnerability was identified in the Linux kernel’s io_uring subsystem, specifically in SQPOLL error handling. If io_uring_alloc_task_context() fails while io_sq_thread() runs and completes before the error handling executes, io_sq_thread_finish() may attempt to access an already freed task, leading to potential system instability. While the issue is mostly theoretical and requires fault injection to trigger, could lead to crashes or unpredictable behavior.

This CVE has been rejected upstream: https://lore.kernel.org/linux-cve-announce/2025010720-REJECTED-2931@gregkh/

IO uring support enabled only in latest versions of Red Hat Enterprise Linux. The bug could happen only if some complex conditions, so the security impact is Moderate: "if io_uring_alloc_task_context() fails and then io_sq_thread() manages to run and complete before the rest of error handling code, which means io_sq_thread_finish() is looking at already killed task."