# CVE-2022-49827: drm: Fix potential null-ptr-deref in drm_vblank_destroy_worker()

> A null pointer dereference in the Linux kernel DRM subsystem can cause a system crash during module initialization.

- **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:** 1 May 2025
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2022-49827, GHSA-mc9r-5hj8-m6xw, UBUNTU-CVE-2022-49827

## What is CVE-2022-49827?

CVE-2022-49827 is a medium-severity vulnerability in Linux kernel, published on 1 May 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: Fix potential null-ptr-deref in drm_vblank_destroy_worker()

drm_vblank_init() call drmm_add_action_or_reset() with
drm_vblank_init_release() as action. If __drmm_add_action() failed, will
directly call drm_vblank_init_release() with the vblank whose worker is
NULL. As the resule, a null-ptr-deref will happen in
kthread_destroy_worker(). Add the NULL check before calling
drm_vblank_destroy_worker().

BUG: null-ptr-deref
KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f]
CPU: 5 PID: 961 Comm: modprobe Not tainted 6.0.0-11331-gd465bff130bf-dirty
RIP: 0010:kthread_destroy_worker+0x25/0xb0
  Call Trace:
    <TASK>
    drm_vblank_init_release+0x124/0x220 [drm]
    ? drm_crtc_vblank_restore+0x8b0/0x8b0 [drm]
    __drmm_add_action_or_reset+0x41/0x50 [drm]
    drm_vblank_init+0x282/0x310 [drm]
    vkms_init+0x35f/0x1000 [vkms]
    ? 0xffffffffc4508000
    ? lock_is_held_type+0xd7/0x130
    ? __kmem_cache_alloc_node+0x1c2/0x2b0
    ? lock_is_held_type+0xd7/0x130
    ? 0xffffffffc4508000
    do_one_initcall+0xd0/0x4f0
    ...
    do_syscall_64+0x35/0x80
    entry_SYSCALL_64_after_hwframe+0x46/0xb0

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2022-49827?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-49827?

Apply the vendor's patch.

## Is CVE-2022-49827 being exploited?

There is no known exploitation of CVE-2022-49827 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-2022-49827 and fix it if it is affected.

What it is: CVE-2022-49827 is a medium-severity vulnerability in Linux kernel, published on 1 May 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-2022-49827 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-2022-49827/ (Markdown: https://insights.sbomify.com/CVE-2022-49827/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-49827
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-49827
- OSV: https://osv.dev/vulnerability/CVE-2022-49827

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-49827/
Summaries are generated and may contain mistakes; the official description above is the record.