# CVE-2023-53832: md/raid10: fix null-ptr-deref in raid10_sync_request

> A null pointer dereference in the Linux kernel RAID10 driver allows local attackers to cause a system crash via specific I/O error and replacement scenarios.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Dec 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-53832, DEBIAN-CVE-2023-53832, GHSA-f28c-m9h4-3wr6, UBUNTU-CVE-2023-53832

## What is CVE-2023-53832?

CVE-2023-53832 is a vulnerability in Linux, published on 9 Dec 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:

md/raid10: fix null-ptr-deref in raid10_sync_request

init_resync() inits mempool and sets conf->have_replacemnt at the beginning
of sync, close_sync() frees the mempool when sync is completed.

After [1] recovery might be skipped and init_resync() is called but
close_sync() is not. null-ptr-deref occurs with r10bio->dev[i].repl_bio.

The following is one way to reproduce the issue.

  1) create a array, wait for resync to complete, mddev->recovery_cp is set
     to MaxSector.
  2) recovery is woken and it is skipped. conf->have_replacement is set to
     0 in init_resync(). close_sync() not called.
  3) some io errors and rdev A is set to WantReplacement.
  4) a new device is added and set to A's replacement.
  5) recovery is woken, A have replacement, but conf->have_replacemnt is
     0. r10bio->dev[i].repl_bio will not be alloced and null-ptr-deref
     occurs.

Fix it by not calling init_resync() if recovery skipped.

[1] commit 7e83ccbecd60 ("md/raid10: Allow skipping recovery when clean arrays are assembled")

## Which versions are affected by CVE-2023-53832?


## How do I fix CVE-2023-53832?

Apply the vendor's patch.

## Is CVE-2023-53832 being exploited?

There is no known exploitation of CVE-2023-53832 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-53832 and fix it if it is affected.

What it is: CVE-2023-53832 is a vulnerability in Linux, published on 9 Dec 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-2023-53832 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-2023-53832/ (Markdown: https://insights.sbomify.com/CVE-2023-53832/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53832
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53832
- OSV: https://osv.dev/vulnerability/CVE-2023-53832

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53832/
Summaries are generated and may contain mistakes; the official description above is the record.