CVE-2026-99253
io_uring/cancel: rearm local work wake up before sleep
- Published
- Updated
- Reserved
- Assigned by
- Linux
Description
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.
Scores
No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Received.
- EPSS (exploitation in 30 days)
- 0.18% · top 93% of all CVEs (6 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.
Affected products
- affected d46ab2c98ababa19b41a5709b6921d7b1add7f74 – < aaa06bb9fc03384f7cf2dbc3e43f2939cc7791b2
- affected d46ab2c98ababa19b41a5709b6921d7b1add7f74 – < 58ddf0ec707093206a5fe814581ec5aefac8b08a
- affected d46ab2c98ababa19b41a5709b6921d7b1add7f74 – < 76a82c666abf155ad52d5f41043eac77dd3e41d8
- affected 7.2
- unaffected < 7.2
- unaffected 7.2.14 – ≤ 7.2.*
- unaffected 7.3.2 – ≤ 7.3.*
- unaffected 7.4-rc1 – ≤ *
References (3)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://trackcve.app/cve/CVE-2026-99253)Record last updated .