CVSS
Вероятност да бъде експлоатирана в следващите 30 дни (EPSS)
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Описание
Оригинално описание
In the Linux kernel, the following vulnerability has been resolved: io_uring/cancel: rearm local work wake up before sleep io_uring_try_cancel_requests() sets ->cq_wait_nr to 1 so that the next io_req_local_work_add() wakes the cancelling task. The add that takes the count to zero is the only one that wakes, later ones see a count <= 0 and return. io_uring_cancel_generic() however only becomes TASK_INTERRUPTIBLE much later, so the one wake up can be spent on a running task. That is fine as long as the entry of that add is still queued, as the io_local_work_pending() check then skips the sleep. It is not if the add was delayed after queueing its entry: CPU0 (submitter in exec or exit) CPU1 (io_req_local_work_add) mpscq_push(req A) io_uring_try_cancel_requests() io_run_local_work() // runs req A io_uring_try_cancel_requests() atomic_set(&ctx->cq_wait_nr, 1) atomic_read(&ctx->cq_wait_nr) == 1 count taken, wake_up_state() // task is running, no-op prepare_to_wait(TASK_INTERRUPTIBLE) io_local_work_pending() == false schedule() mpscq_push(req B) cq_wait_nr <= 0, return Only the sleeping task can run req B, so it is stuck in execve() until a signal happens to wake it. An exiting task doesn't even get that. Arm the count again once the task state is set and before the work list is checked, for the rings whose local work this task is the one to run.
Засегнати продукти
- Linux Linux: d46ab2c98ababa19b41a5709b6921d7b1add7f74 преди aaa06bb9fc03384f7cf2dbc3e43f2939cc7791b2; d46ab2c98ababa19b41a5709b6921d7b1add7f74 преди 76a82c666abf155ad52d5f41043eac77dd3e41d8
- Linux Linux: 7.2; преди 7.2; 7.2.14 до 7.2.*; от 7.4-rc1 нататък
История
- 3 ноември 2026 Публикувано