---
id: CVE-2023-52503
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  tee: amdtee: fix use-after-free vulnerability in amdtee_close_session

  There is a potential race condition in amdtee_close_session that may
  cause use-after-free in amdt…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  tee: amdtee: fix use-after-free vulnerability in amdtee_close_session

  There is a potential race condition in amdtee_close_session that may
  cause use-after-free in amdt…
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'
cwe:
  - CWE-416
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 5.6, < 5.10.199'
  - 'linux_kernel >= 5.11, < 5.15.136'
  - 'linux_kernel >= 5.16, < 6.1.59'
  - 'linux_kernel >= 6.2, < 6.5.8'
  - linux_kernel = 6.6
patched:
  - linux_kernel 6.5.8
published: '2024-03-02'
updated: '2026-08-04'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2023-52503'
references:
  - url: 'https://git.kernel.org/stable/c/1680c82929bc14d706065f123dab77f2f1293116'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/1c95574350cd63bc3c5c2fa06658010768f2a0ce'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/60c3e7a00db954947c265b55099c21b216f2a05c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/da7ce52a2f6c468946195b116615297d3d113a27'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f4384b3e54ea813868bb81a861bf5b2406e15d8f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/1680c82929bc14d706065f123dab77f2f1293116'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/1c95574350cd63bc3c5c2fa06658010768f2a0ce'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/60c3e7a00db954947c265b55099c21b216f2a05c'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/da7ce52a2f6c468946195b116615297d3d113a27'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/f4384b3e54ea813868bb81a861bf5b2406e15d8f'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00258
epssPercentile: 0.17815
ingestedAt: '2026-08-04T10:39:40.009Z'
---

## Overview

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

tee: amdtee: fix use-after-free vulnerability in amdtee_close_session

There is a potential race condition in amdtee_close_session that may
cause use-after-free in amdtee_open_session. For instance, if a session
has refcount == 1, and one thread tries to free this session via:

    kref_put(&sess->refcount, destroy_session);

the reference count will get decremented, and the next step would be to
call destroy_session(). However, if in another thread,
amdtee_open_session() is called before destroy_session() has completed
execution, alloc_session() may return 'sess' that will be freed up
later in destroy_session() leading to use-after-free in
amdtee_open_session.

To fix this issue, treat decrement of sess->refcount and removal of
'sess' from session list in destroy_session() as a critical section, so
that it is executed atomically.

## Affected

- `linux_kernel >= 5.6, < 5.10.199`
- `linux_kernel >= 5.11, < 5.15.136`
- `linux_kernel >= 5.16, < 6.1.59`
- `linux_kernel >= 6.2, < 6.5.8`
- `linux_kernel = 6.6`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.5.8`