CVE-2026-46274 (GCVE-0-2026-46274)

Vulnerability from cvelistv5 – Published: 2026-06-08 14:30 – Updated: 2026-06-14 18:05
VLAI
Title
io-wq: check that the predecessor is hashed in io_wq_remove_pending()
Summary
In the Linux kernel, the following vulnerability has been resolved: io-wq: check that the predecessor is hashed in io_wq_remove_pending() io_wq_remove_pending() needs to fix up wq->hash_tail[] if the cancelled work was the tail of its hash bucket. When doing this, it checks whether the preceding entry in acct->work_list has the same hash value, but never checks that the predecessor is hashed at all. io_get_work_hash() is simply atomic_read(&work->flags) >> IO_WQ_HASH_SHIFT, and the hash bits are never set for non-hashed work, so it returns 0. Thus, when a hashed bucket-0 work is cancelled while a non-hashed work is its list predecessor, the check spuriously passes and a pointer to the non-hashed io_kiocb is stored in wq->hash_tail[0]. Because non-hashed work is dequeued via the fast path in io_get_next_work(), which never touches hash_tail[], the stale pointer is never cleared. Therefore, after the non-hashed io_kiocb completes and is freed back to req_cachep, wq->hash_tail[0] is a dangling pointer. The io_wq is per-task (tctx->io_wq) and survives ring open/close, so the dangling pointer persists for the lifetime of the task; the next hashed bucket-0 enqueue dereferences it in io_wq_insert_work() and wq_list_add_after() writes through freed memory. Add the missing io_wq_is_hashed() check so a non-hashed predecessor never inherits a hash_tail[] slot.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 204361a77f4018627addd4a06877448f088ddfc0 , < d6bda9df0c0a3080804181464d5c0f4d78a4e769 (git)
Affected: 204361a77f4018627addd4a06877448f088ddfc0 , < 5a20ebf0c81b61f5ea3b1b529c100cad69b9f603 (git)
Affected: 204361a77f4018627addd4a06877448f088ddfc0 , < 252c5051dba9c709b6a72f2866f93e5e618b3f06 (git)
Affected: 204361a77f4018627addd4a06877448f088ddfc0 , < d376c131af7c7739a87ff037ed2fdb67c2542c8a (git)
Affected: 204361a77f4018627addd4a06877448f088ddfc0 , < d6a2d7b04b5a093021a7a0e2e69e9d5237dfa8cc (git)
Affected: 13f35a2c0fd5c6a4fcd8903542b053bcc914fcf5 (git)
Affected: 5.8.6 , < 5.9 (semver)
Create a notification for this product.
Linux Linux Affected: 5.9
Unaffected: 0 , < 5.9 (semver)
Unaffected: 6.6.141 , ≤ 6.6.* (semver)
Unaffected: 6.12.91 , ≤ 6.12.* (semver)
Unaffected: 6.18.33 , ≤ 6.18.* (semver)
Unaffected: 7.0.10 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
Create a notification for this product.
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  }
}



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