# CVE-2023-53731: netlink: fix potential deadlock in netlink_set_err()

> A local attacker can trigger a deadlock in the Linux kernel netlink subsystem, causing a denial of service.

- **Severity:** Not scored
- **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:** 22 Oct 2025
- **Updated:** 23 May 2026
- **Also known as:** BELL-CVE-2023-53731, DEBIAN-CVE-2023-53731, GHSA-cj8f-58h8-h475, UBUNTU-CVE-2023-53731

## What is CVE-2023-53731?

CVE-2023-53731 is a vulnerability in Linux, published on 22 Oct 2025. 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:

netlink: fix potential deadlock in netlink_set_err()

syzbot reported a possible deadlock in netlink_set_err() [1]

A similar issue was fixed in commit 1d482e666b8e ("netlink: disable IRQs
for netlink_lock_table()") in netlink_lock_table()

This patch adds IRQ safety to netlink_set_err() and __netlink_diag_dump()
which were not covered by cited commit.

[1]

WARNING: possible irq lock inversion dependency detected
6.4.0-rc6-syzkaller-00240-g4e9f0ec38852 #0 Not tainted

syz-executor.2/23011 just changed the state of lock:
ffffffff8e1a7a58 (nl_table_lock){.+.?}-{2:2}, at: netlink_set_err+0x2e/0x3a0 net/netlink/af_netlink.c:1612
but this lock was taken by another, SOFTIRQ-safe lock in the past:
 (&local->queue_stop_reason_lock){..-.}-{2:2}

and interrupts could create inverse lock ordering between them.

other info that might help us debug this:
 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(nl_table_lock);
                               local_irq_disable();
                               lock(&local->queue_stop_reason_lock);
                               lock(nl_table_lock);
  <Interrupt>
    lock(&local->queue_stop_reason_lock);

 *** DEADLOCK ***

## Which versions are affected by CVE-2023-53731?


## How do I fix CVE-2023-53731?

Apply the vendor's patch.

## Is CVE-2023-53731 being exploited?

There is no known exploitation of CVE-2023-53731 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-53731 and fix it if it is affected.

What it is: CVE-2023-53731 is a vulnerability in Linux, published on 22 Oct 2025. 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-2023-53731 in the wild and no public exploit code.

Affected product: 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-2023-53731/ (Markdown: https://insights.sbomify.com/CVE-2023-53731/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53731
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53731
- OSV: https://osv.dev/vulnerability/CVE-2023-53731

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53731/
Summaries are generated and may contain mistakes; the official description above is the record.