# CVE-2023-52699: sysv: don't call sb_bread() with pointers_lock held

> A race condition in the Linux kernel SysV filesystem causes a deadlock when sb_bread() is called with a lock held, leading to denial of service.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 19 May 2024
- **Updated:** 15 Oct 2026
- **Also known as:** BELL-CVE-2023-52699, DEBIAN-CVE-2023-52699, GHSA-29pq-gr25-8674, UBUNTU-CVE-2023-52699

## What is CVE-2023-52699?

CVE-2023-52699 is a medium-severity vulnerability in Debian Debian Linux, published on 19 May 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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

sysv: don't call sb_bread() with pointers_lock held

syzbot is reporting sleep in atomic context in SysV filesystem [1], for
sb_bread() is called with rw_spinlock held.

A "write_lock(&pointers_lock) => read_lock(&pointers_lock) deadlock" bug
and a "sb_bread() with write_lock(&pointers_lock)" bug were introduced by
"Replace BKL for chain locking with sysvfs-private rwlock" in Linux 2.5.12.

Then, "[PATCH] err1-40: sysvfs locking fix" in Linux 2.6.8 fixed the
former bug by moving pointers_lock lock to the callers, but instead
introduced a "sb_bread() with read_lock(&pointers_lock)" bug (which made
this problem easier to hit).

Al Viro suggested that why not to do like get_branch()/get_block()/
find_shared() in Minix filesystem does. And doing like that is almost a
revert of "[PATCH] err1-40: sysvfs locking fix" except that get_branch()
 from with find_shared() is called without write_lock(&pointers_lock).

Weakness: CWE-667 (Improper Locking)

## Which versions are affected by CVE-2023-52699?

It affects 2 products.


Products: Debian Debian Linux, Linux kernel.

## How do I fix CVE-2023-52699?

Apply the vendor's patch.

## Is CVE-2023-52699 being exploited?

There is no known exploitation of CVE-2023-52699 in the wild and no public exploit code.

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- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-52699 and fix it if it is affected.

What it is: CVE-2023-52699 is a medium-severity vulnerability in Debian Debian Linux, published on 19 May 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-52699 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2023-52699/ (Markdown: https://insights.sbomify.com/CVE-2023-52699/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-52699
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-52699
- OSV: https://osv.dev/vulnerability/CVE-2023-52699

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-52699/
Summaries are generated and may contain mistakes; the official description above is the record.