# CVE-2024-53131: nilfs2: fix null-ptr-deref in block_touch_buffer tracepoint

> A null pointer dereference in the nilfs2 filesystem can cause a kernel crash when specific block tracepoints are enabled.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 4 Dec 2024
- **Updated:** 11 May 2026
- **Also known as:** AZL-54131, AZL-54150, BELL-CVE-2024-53131, DEBIAN-CVE-2024-53131, GHSA-p85v-4hp9-vq4r, UBUNTU-CVE-2024-53131

## What is CVE-2024-53131?

CVE-2024-53131 is a medium-severity vulnerability in Linux kernel, published on 4 Dec 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:

nilfs2: fix null-ptr-deref in block_touch_buffer tracepoint

Patch series "nilfs2: fix null-ptr-deref bugs on block tracepoints".

This series fixes null pointer dereference bugs that occur when using
nilfs2 and two block-related tracepoints.

This patch (of 2):

It has been reported that when using "block:block_touch_buffer"
tracepoint, touch_buffer() called from __nilfs_get_folio_block() causes a
NULL pointer dereference, or a general protection fault when KASAN is
enabled.

This happens because since the tracepoint was added in touch_buffer(), it
references the dev_t member bh->b_bdev->bd_dev regardless of whether the
buffer head has a pointer to a block_device structure.  In the current
implementation, the block_device structure is set after the function
returns to the caller.

Here, touch_buffer() is used to mark the folio/page that owns the buffer
head as accessed, but the common search helper for folio/page used by the
caller function was optimized to mark the folio/page as accessed when it
was reimplemented a long time ago, eliminating the need to call
touch_buffer() here in the first place.

So this solves the issue by eliminating the touch_buffer() call itself.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2024-53131?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-53131?

Apply the vendor's patch.

## Is CVE-2024-53131 being exploited?

There is no known exploitation of CVE-2024-53131 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-2024-53131 and fix it if it is affected.

What it is: CVE-2024-53131 is a medium-severity vulnerability in Linux kernel, published on 4 Dec 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-2024-53131 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-2024-53131/ (Markdown: https://insights.sbomify.com/CVE-2024-53131/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-53131
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-53131
- OSV: https://osv.dev/vulnerability/CVE-2024-53131

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-53131/
Summaries are generated and may contain mistakes; the official description above is the record.