# CVE-2024-44992: smb/client: avoid possible NULL dereference in cifs_free_subrequest()

> A null pointer dereference in the Linux kernel SMB client can cause a system crash, requiring a kernel patch to prevent denial of service.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 4 Sep 2024
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2024-44992, DEBIAN-CVE-2024-44992, GHSA-53cv-6gxv-7335, UBUNTU-CVE-2024-44992

## What is CVE-2024-44992?

CVE-2024-44992 is a high-severity vulnerability in Linux kernel, published on 4 Sep 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:

smb/client: avoid possible NULL dereference in cifs_free_subrequest()

Clang static checker (scan-build) warning:
	cifsglob.h:line 890, column 3
	Access to field 'ops' results in a dereference of a null pointer.

Commit 519be989717c ("cifs: Add a tracepoint to track credits involved in
R/W requests") adds a check for 'rdata->server', and let clang throw this
warning about NULL dereference.

When 'rdata->credits.value != 0 && rdata->server == NULL' happens,
add_credits_and_wake_if() will call rdata->server->ops->add_credits().
This will cause NULL dereference problem. Add a check for 'rdata->server'
to avoid NULL dereference.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2024-44992?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-44992?

Apply the vendor's patch.

## Is CVE-2024-44992 being exploited?

There is no known exploitation of CVE-2024-44992 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-2024-44992 and fix it if it is affected.

What it is: CVE-2024-44992 is a high-severity vulnerability in Linux kernel, published on 4 Sep 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-2024-44992 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-2024-44992/ (Markdown: https://insights.sbomify.com/CVE-2024-44992/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-44992
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-44992
- OSV: https://osv.dev/vulnerability/CVE-2024-44992

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-44992/
Summaries are generated and may contain mistakes; the official description above is the record.