# CVE-2025-40148: drm/amd/display: Add NULL pointer checks in dc_stream cursor attribute functions

> A missing NULL pointer check in the Linux kernel's AMD display driver can cause a system crash when processing cursor attributes.

- **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:** 12 Nov 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2025-40148, DEBIAN-CVE-2025-40148, GHSA-7hf4-2fh2-36rm, UBUNTU-CVE-2025-40148

## What is CVE-2025-40148?

CVE-2025-40148 is a vulnerability in Linux, published on 12 Nov 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/amd/display: Add NULL pointer checks in dc_stream cursor attribute functions

The function dc_stream_set_cursor_attributes() currently dereferences
the `stream` pointer and nested members `stream->ctx->dc->current_state`
without checking for NULL.

All callers of these functions, such as in
`dcn30_apply_idle_power_optimizations()` and
`amdgpu_dm_plane_handle_cursor_update()`, already perform NULL checks
before calling these functions.

Fixes below:
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c:336 dc_stream_program_cursor_attributes()
error: we previously assumed 'stream' could be null (see line 334)

drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c
    327 bool dc_stream_program_cursor_attributes(
    328         struct dc_stream_state *stream,
    329         const struct dc_cursor_attributes *attributes)
    330 {
    331         struct dc  *dc;
    332         bool reset_idle_optimizations = false;
    333
    334         dc = stream ? stream->ctx->dc : NULL;
                     ^^^^^^
The old code assumed stream could be NULL.

    335
--> 336         if (dc_stream_set_cursor_attributes(stream, attributes)) {
                                                    ^^^^^^
The refactor added an unchecked dereference.

drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c
   313  bool dc_stream_set_cursor_attributes(
   314          struct dc_stream_state *stream,
   315          const struct dc_cursor_attributes *attributes)
   316  {
   317          bool result = false;
   318
   319          if (dc_stream_check_cursor_attributes(stream, stream->ctx->dc->current_state, attributes)) {
                                                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Here.
This function used to check for if stream as NULL and return false at
the start. Probably we should add that back.

## Which versions are affected by CVE-2025-40148?


## How do I fix CVE-2025-40148?

Apply the vendor's patch.

## Is CVE-2025-40148 being exploited?

There is no known exploitation of CVE-2025-40148 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-40148 and fix it if it is affected.

What it is: CVE-2025-40148 is a vulnerability in Linux, published on 12 Nov 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-2025-40148 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-2025-40148/ (Markdown: https://insights.sbomify.com/CVE-2025-40148/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-40148
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-40148
- OSV: https://osv.dev/vulnerability/CVE-2025-40148

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-40148/
Summaries are generated and may contain mistakes; the official description above is the record.