---
id: CVE-2026-53273
title: 'tee: optee: prevent use-after-free when the client exits before the supplicant'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  tee: optee: prevent use-after-free when the client exits before the supplicant

  Commit 70b0d6b0a199 ("tee: optee: Fix supplicant wait loop") made the
  client wait as kil…
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
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 0180cf0373f84fff61b16f8c062553a13dd7cfca <
    416259cb5bffecaaae5f76539deb535a8c1b2c34
  - >-
    Linux >= c0a9a948159153be145f9471435695373904ee6d <
    724d0caffd4204b46f78efe22f18f8338031c6e1
  - >-
    Linux >= ec18520f5edc20a00c34a8c9fdd6507c355e880f <
    ae847ab29ded2d7cece4d5970f0edefa4137bf2f
  - >-
    Linux >= d61cc1a435e6894bfb0dd3370c6f765d2d12825d <
    9a0dc9279d0907b198f205a693aedf696b08145d
  - >-
    Linux >= fd9d2d6124c293e40797a080adf8a9c237efd8b8 <
    d366a01475f927402c96a3fe78bfc06b924fc87d
  - >-
    Linux >= 70b0d6b0a199c5a3ee6c72f5e61681ed6f759612 <
    d5b57bb314d79e99bebb58a53588fa11dd4dbf69
  - >-
    Linux >= 70b0d6b0a199c5a3ee6c72f5e61681ed6f759612 <
    373152c94e57e9592b68c100e224fbd943cfd608
  - >-
    Linux >= 70b0d6b0a199c5a3ee6c72f5e61681ed6f759612 <
    387a926ee166814611acecb960207fe2f3c4fd3e
  - Linux 3eb4911364c764572e9db4ab900a57689a54e8ce
  - Linux 21234efe2a8474a6d2d01ea9573319de7858ce44
  - Linux >= 5.10.235 < 5.10.259
  - Linux >= 5.15.179 < 5.15.210
  - Linux >= 6.1.130 < 6.1.176
  - Linux >= 6.6.80 < 6.6.143
  - Linux >= 6.12.17 < 6.12.94
  - Linux >= 5.4.291 < 5.5
  - Linux >= 6.13.5 < 6.14
  - Linux 6.14
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T15:28:16.410790Z'
published: '2026-06-25'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:31:45.010Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-53273'
references:
  - url: 'https://git.kernel.org/stable/c/416259cb5bffecaaae5f76539deb535a8c1b2c34'
  - url: 'https://git.kernel.org/stable/c/724d0caffd4204b46f78efe22f18f8338031c6e1'
  - url: 'https://git.kernel.org/stable/c/ae847ab29ded2d7cece4d5970f0edefa4137bf2f'
  - url: 'https://git.kernel.org/stable/c/9a0dc9279d0907b198f205a693aedf696b08145d'
  - url: 'https://git.kernel.org/stable/c/d366a01475f927402c96a3fe78bfc06b924fc87d'
  - url: 'https://git.kernel.org/stable/c/d5b57bb314d79e99bebb58a53588fa11dd4dbf69'
  - url: 'https://git.kernel.org/stable/c/373152c94e57e9592b68c100e224fbd943cfd608'
  - url: 'https://git.kernel.org/stable/c/387a926ee166814611acecb960207fe2f3c4fd3e'
tags:
  - cve.org
epss: 0.00117
epssPercentile: 0.0157
ingestedAt: '2026-10-16T17:24:46.741Z'
---

## Overview

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

tee: optee: prevent use-after-free when the client exits before the supplicant

Commit 70b0d6b0a199 ("tee: optee: Fix supplicant wait loop") made the
client wait as killable so it can be interrupted during shutdown or
after a supplicant crash. This changes the original lifetime expectations:
the client task can now terminate while the supplicant is still processing
its request.

If the client exits first it removes the request from its queue and
kfree()s it, while the request ID remains in supp->idr. A subsequent
lookup on the supplicant path then dereferences freed memory, leading to
a use-after-free.

Serialise access to the request with supp->mutex:

  * Hold supp->mutex in optee_supp_recv() and optee_supp_send() while
    looking up and touching the request.
  * Let optee_supp_thrd_req() notice that the client has terminated and
    signal optee_supp_send() accordingly.

With these changes the request cannot be freed while the supplicant still
has a reference, eliminating the race.

## Affected

- `Linux >= 0180cf0373f84fff61b16f8c062553a13dd7cfca < 416259cb5bffecaaae5f76539deb535a8c1b2c34`
- `Linux >= c0a9a948159153be145f9471435695373904ee6d < 724d0caffd4204b46f78efe22f18f8338031c6e1`
- `Linux >= ec18520f5edc20a00c34a8c9fdd6507c355e880f < ae847ab29ded2d7cece4d5970f0edefa4137bf2f`
- `Linux >= d61cc1a435e6894bfb0dd3370c6f765d2d12825d < 9a0dc9279d0907b198f205a693aedf696b08145d`
- `Linux >= fd9d2d6124c293e40797a080adf8a9c237efd8b8 < d366a01475f927402c96a3fe78bfc06b924fc87d`
- `Linux >= 70b0d6b0a199c5a3ee6c72f5e61681ed6f759612 < d5b57bb314d79e99bebb58a53588fa11dd4dbf69`
- `Linux >= 70b0d6b0a199c5a3ee6c72f5e61681ed6f759612 < 373152c94e57e9592b68c100e224fbd943cfd608`
- `Linux >= 70b0d6b0a199c5a3ee6c72f5e61681ed6f759612 < 387a926ee166814611acecb960207fe2f3c4fd3e`
- `Linux 3eb4911364c764572e9db4ab900a57689a54e8ce`
- `Linux 21234efe2a8474a6d2d01ea9573319de7858ce44`
- `Linux >= 5.10.235 < 5.10.259`
- `Linux >= 5.15.179 < 5.15.210`
- `Linux >= 6.1.130 < 6.1.176`
- `Linux >= 6.6.80 < 6.6.143`
- `Linux >= 6.12.17 < 6.12.94`
- `Linux >= 5.4.291 < 5.5`
- `Linux >= 6.13.5 < 6.14`
- `Linux 6.14`

## Remediation

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