exit: prevent preemption of oopsing TASK_DEAD task (Linux Linux)

CVE-2026-46173
HIGH 7.8

En bref

Source
NVD
EPSS
EPSS 0.13 % · centile 3 ()
État
PUBLISHED
Publiée
Mise à jour
Attribuée par
Linux
Statut NVD
Modified

Description

In the Linux kernel, the following vulnerability has been resolved: exit: prevent preemption of oopsing TASK_DEAD task When an already-exiting task oopses, make_task_dead() currently calls do_task_dead() with preemption enabled. That is forbidden: do_task_dead() calls __schedule(), which has a comment saying "WARNING: must be called with preemption disabled!". If an oopsing task is preempted in do_task_dead(), between becoming TASK_DEAD and entering the scheduler explicitly, bad things happen: finish_task_switch() assumes that once the scheduler has switched away from a TASK_DEAD task, the task can never run again and its stack is no longer needed; but that assumption apparently doesn't hold if the dead task was preempted (the SM_PREEMPT case). This means that the scheduler ends up repeatedly dropping references on the dead task's stack, which can lead to use-after-free or double-free of the entire task stack; in other words, two tasks can end up running on the same stack, resulting in various kinds of memory corruption. (This does not just affect "recursively oopsing" tasks; it is enough to oops once during task exit, for example in a file_operations::release handler)

Faiblesses (CWE)

  • CWE-416 — Utilisation après libération
  • CWE-787 — Écriture hors limites

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 7f80a2fd7db9a55894fd841915236aca611291b5 < 3d6fb8a7690c23e3213c4b008f64d89a44b98737 ; affected 7f80a2fd7db9a55894fd841915236aca611291b5 < 640b4c00fb0e2920327435f6176cbefc3c546165 ; affected 7f80a2fd7db9a55894fd841915236aca611291b5 < 7b2800ba5f5f77a8ee7f4cbadb19cf1264597a34 ; affected 7f80a2fd7db9a55894fd841915236aca611291b5 < 6f49f94f3b11fe8bff1bf2a054143789e76aaf17 ; affected 7f80a2fd7db9a55894fd841915236aca611291b5 < 9756b3db5db6c2f5eccb32dddbd88eb4c54f575e ; affected 7f80a2fd7db9a55894fd841915236aca611291b5 < c1fa0bb633e4a6b11e83ffc57fa5abe8ebb87891
Linux · Linuxaffected 5.17 ; unaffected 0 < 5.17 ; unaffected 6.1.175 ≤ 6.1.* ; unaffected 6.6.140 ≤ 6.6.* ; unaffected 6.12.88 ≤ 6.12.* ; unaffected 6.18.30 ≤ 6.18.*

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