# CVE-2023-52503: tee: amdtee: fix use-after-free vulnerability in amdtee_close_session

> A race condition in the Linux kernel's AMD TEE driver allows a use-after-free, potentially enabling local attackers to execute arbitrary code or escalate privileges.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 2 Mar 2024
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2023-52503, DEBIAN-CVE-2023-52503, GHSA-c5gm-r7c3-j9cp, UBUNTU-CVE-2023-52503

## What is CVE-2023-52503?

CVE-2023-52503 is a high-severity use after free vulnerability in Linux kernel, published on 2 Mar 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2023-52503?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-52503?

Apply the vendor's patch.

## Is CVE-2023-52503 being exploited?

There is no known exploitation of CVE-2023-52503 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-52503 and fix it if it is affected.

What it is: CVE-2023-52503 is a high-severity use after free vulnerability in Linux kernel, published on 2 Mar 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-52503 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2023-52503/ (Markdown: https://insights.sbomify.com/CVE-2023-52503/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-52503
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-52503
- OSV: https://osv.dev/vulnerability/CVE-2023-52503

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-52503/
Summaries are generated and may contain mistakes; the official description above is the record.