# CVE-2023-53991: drm/msm/dpu: Disallow unallocated resources to be returned

> A null pointer dereference in the Linux kernel DPU driver allows local attackers to cause a system lockup or 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:** 24 Dec 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-53991, DEBIAN-CVE-2023-53991, GHSA-8m95-4p4w-6hv6, UBUNTU-CVE-2023-53991

## What is CVE-2023-53991?

CVE-2023-53991 is a vulnerability in Linux, published on 24 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:

drm/msm/dpu: Disallow unallocated resources to be returned

In the event that the topology requests resources that have not been
created by the system (because they are typically not represented in
dpu_mdss_cfg ^1), the resource(s) in global_state (in this case DSC
blocks, until their allocation/assignment is being sanity-checked in
"drm/msm/dpu: Reject topologies for which no DSC blocks are available")
remain NULL but will still be returned out of
dpu_rm_get_assigned_resources, where the caller expects to get an array
containing num_blks valid pointers (but instead gets these NULLs).

To prevent this from happening, where null-pointer dereferences
typically result in a hard-to-debug platform lockup, num_blks shouldn't
increase past NULL blocks and will print an error and break instead.
After all, max_blks represents the static size of the maximum number of
blocks whereas the actual amount varies per platform.

^1: which can happen after a git rebase ended up moving additions to
_dpu_cfg to a different struct which has the same patch context.

Patchwork: https://patchwork.freedesktop.org/patch/517636/

## Which versions are affected by CVE-2023-53991?


## How do I fix CVE-2023-53991?

Apply the vendor's patch.

## Is CVE-2023-53991 being exploited?

There is no known exploitation of CVE-2023-53991 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-53991 and fix it if it is affected.

What it is: CVE-2023-53991 is a vulnerability in Linux, published on 24 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-2023-53991 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-2023-53991/ (Markdown: https://insights.sbomify.com/CVE-2023-53991/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53991
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53991
- OSV: https://osv.dev/vulnerability/CVE-2023-53991

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53991/
Summaries are generated and may contain mistakes; the official description above is the record.