---
id: CVE-2026-80928
title: 'smack: fix cred UAF in smack_file_send_sigiotask()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  smack: fix cred UAF in smack_file_send_sigiotask()

  When inspecting the credentials of another task, objective credentials
  (->real_cred, accessed with __task_cred()) mu…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-825
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 3b11a1decef07c19443d24ae926982bc8ec9f4c0 <
    a512366d84e134a9eefc2cc40eeb6e80e2ec162c
  - >-
    Linux >= 3b11a1decef07c19443d24ae926982bc8ec9f4c0 <
    7c7fe043f3099d0d35002b248967f75e55345b93
  - >-
    Linux >= 3b11a1decef07c19443d24ae926982bc8ec9f4c0 <
    f9c7b1f2b9d8f4176d2632743f51400855978ace
  - >-
    Linux >= 3b11a1decef07c19443d24ae926982bc8ec9f4c0 <
    b5bcf3adfa27279da4401ab8f1e1a706601a92be
  - >-
    Linux >= 3b11a1decef07c19443d24ae926982bc8ec9f4c0 <
    ed64aa505875a3b4defd504ee8e59e1949246a62
  - >-
    Linux >= 3b11a1decef07c19443d24ae926982bc8ec9f4c0 <
    b791401bf389a1546a830d2b381ca60fe94c7870
  - >-
    Linux >= 3b11a1decef07c19443d24ae926982bc8ec9f4c0 <
    fedc88e38ce979a720cd2de042578cb5df3dc8de
  - Linux 2.6.29
published: '2026-09-11'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T08:45:12.134Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-80928'
references:
  - url: 'https://git.kernel.org/stable/c/a512366d84e134a9eefc2cc40eeb6e80e2ec162c'
  - url: 'https://git.kernel.org/stable/c/7c7fe043f3099d0d35002b248967f75e55345b93'
  - url: 'https://git.kernel.org/stable/c/f9c7b1f2b9d8f4176d2632743f51400855978ace'
  - url: 'https://git.kernel.org/stable/c/b5bcf3adfa27279da4401ab8f1e1a706601a92be'
  - url: 'https://git.kernel.org/stable/c/ed64aa505875a3b4defd504ee8e59e1949246a62'
  - url: 'https://git.kernel.org/stable/c/b791401bf389a1546a830d2b381ca60fe94c7870'
  - url: 'https://git.kernel.org/stable/c/fedc88e38ce979a720cd2de042578cb5df3dc8de'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80928.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-80928'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532381'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-80928'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-80928'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-80928.mbox
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
  - score-dispute
epss: 0.00129
epssPercentile: 0.02535
scores:
  cna: 7.8
  vendor: 5.5
ingestedAt: '2026-09-14T15:23:07.455Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

smack: fix cred UAF in smack_file_send_sigiotask()

When inspecting the credentials of another task, objective credentials
(->real_cred, accessed with __task_cred()) must always be used.

Accessing ->cred on a non-current task is forbidden unless that task is
being created or destroyed; a task is allowed to change its own ->cred
pointer with no synchronization, and changing ->cred should only affect the
current syscall.

smack_file_send_sigiotask() was accessing both sets of credentials: First
tsk->cred, then __task_cred(tsk).

Fix it, always access the objective credentials here.

I have tested that this bug can lead to a KASAN-reported UAF of struct cred
in smack_file_send_sigiotask(), and that this fix prevents the race.

## Affected

- `Linux >= 3b11a1decef07c19443d24ae926982bc8ec9f4c0 < a512366d84e134a9eefc2cc40eeb6e80e2ec162c`
- `Linux >= 3b11a1decef07c19443d24ae926982bc8ec9f4c0 < 7c7fe043f3099d0d35002b248967f75e55345b93`
- `Linux >= 3b11a1decef07c19443d24ae926982bc8ec9f4c0 < f9c7b1f2b9d8f4176d2632743f51400855978ace`
- `Linux >= 3b11a1decef07c19443d24ae926982bc8ec9f4c0 < b5bcf3adfa27279da4401ab8f1e1a706601a92be`
- `Linux >= 3b11a1decef07c19443d24ae926982bc8ec9f4c0 < ed64aa505875a3b4defd504ee8e59e1949246a62`
- `Linux >= 3b11a1decef07c19443d24ae926982bc8ec9f4c0 < b791401bf389a1546a830d2b381ca60fe94c7870`
- `Linux >= 3b11a1decef07c19443d24ae926982bc8ec9f4c0 < fedc88e38ce979a720cd2de042578cb5df3dc8de`
- `Linux 2.6.29`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Moderate · updated 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80928.json)