CVE-2026-99130CVE-2026-99130

In the Linux kernel, the following vulnerability has been resolved: io_uring/cancel: don't spin on local work the task can't run io_uring_cancel_generic() refuses to sleep while any ring on the exiting task's tctx has local work pending. It assumes the task is that ring's submitter and that the next io_uring_try_cancel_requests() pass will run the work. This does not hold for a ring that was still IORING_SETUP_R_DISABLED when the task got its tctx node from io_uring_create() or io_ringfd_register(). The submitter is set later by IORING_REGISTER_ENABLE_RINGS, possibly from another task, and only the submitter may run local work on an IORING_SETUP_DEFER_TASKRUN ring. To the exiting task the work stays pending forever, the loop never reaches schedule(), and the task trips the WARN_ON_ONCE() once and then spins in do_exit(). An unprivileged user can set this up at will by creating a disabled ring, having a child enable it and stop, posting to the ring with IORING_OP_MSG_RING and exiting