{"id":"CVE-2026-99243","published":"2026-11-03T12:17:30.553","lastModified":"2026-11-03T20:18:30.607","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nio-wq: order the exit bit against worker creation task work\n\nio_wq_exit_workers() cancels task work for queued worker creation with\ntask_work_cancel_match(). That has a plain load of task->task_works.\n\nio_queue_worker_create() adds the new entry and tests IO_WQ_BIT_EXIT to\ncancel it if the workqueue is already on its way out.\n\nThat must be ordered. task_work_add() has a full barrier via cmpxchg().\nBut io_wq_exit_start() sets the bit with set_bit() which doesn't have\nany memory ordering.\n\nSo afaict, on weakly ordered architectures the exiting task may load\ntask_works before the store of the bit is visible. The other side tests\nthe bit before the store is visible as well. So the entry remains queued\nwith worker_refs and the exiting task waits on worker_done indefinitely.\n\nIf the task still has rings then io_uring_del_tctx_node() provides the\nbarrier via test_and_set_bit() in io_wq_set_exit_on_idle(). When it\nhas closed all rings though that barrier is gone.\n\nAdd the barrier after the set_bit().","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/0d81cdd433b0a96c5275c01b8172e0b1f71dd595","tags":[]},{"url":"https://git.kernel.org/stable/c/0e5663856b69219ef2f02e04bac9f5c5be19718a","tags":[]},{"url":"https://git.kernel.org/stable/c/1432d881d99584105122760133caeff1dce7a9f7","tags":[]},{"url":"https://git.kernel.org/stable/c/31fc780b75b278d37700373d54a99fdb4117fdd6","tags":[]},{"url":"https://git.kernel.org/stable/c/67da3eec264aeb67835886720243ae2dc1463315","tags":[]},{"url":"https://git.kernel.org/stable/c/6cf012a4d5e461c788ecc9dbed67adc31a142644","tags":[]},{"url":"https://git.kernel.org/stable/c/75395db7a9b40a2e826c838e648fef8ed1a2d174","tags":[]},{"url":"https://git.kernel.org/stable/c/a63c752157eacf49f628359822666b32503d194a","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}