io-wq: check that the predecessor is hashed in io_wq_remove_pending() (Linux Linux)

CVE-2026-46274
HIGH 7.8

En bref

Source
NVD
EPSS
EPSS 0.14 % · centile 3 ()
État
PUBLISHED
Publiée
Mise à jour
Attribuée par
Linux
Statut NVD
Analyzed

Description

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.

Faiblesses (CWE)

  • CWE-416 — Utilisation après libération

Références

Scores

VersionScoreVecteurÉvalué par
CVSS 3.1HIGH 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HLinux
CVSS 3.1HIGH 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HNVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary)

Références européennes

Avis du CERT-FR

Configurations affectées (CPE NVD)

Produits affectés

ProduitVersions
Linux · Linuxaffected 204361a77f4018627addd4a06877448f088ddfc0 < d6bda9df0c0a3080804181464d5c0f4d78a4e769 ; affected 204361a77f4018627addd4a06877448f088ddfc0 < 5a20ebf0c81b61f5ea3b1b529c100cad69b9f603 ; affected 204361a77f4018627addd4a06877448f088ddfc0 < 252c5051dba9c709b6a72f2866f93e5e618b3f06 ; affected 204361a77f4018627addd4a06877448f088ddfc0 < d376c131af7c7739a87ff037ed2fdb67c2542c8a ; affected 204361a77f4018627addd4a06877448f088ddfc0 < d6a2d7b04b5a093021a7a0e2e69e9d5237dfa8cc ; affected 13f35a2c0fd5c6a4fcd8903542b053bcc914fcf5
Linux · Linuxaffected 5.9 ; unaffected 0 < 5.9 ; unaffected 6.6.141 ≤ 6.6.* ; unaffected 6.12.91 ≤ 6.12.* ; unaffected 6.18.33 ≤ 6.18.* ; unaffected 7.0.10 ≤ 7.0.*

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD