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

Status: published. Published: 2025-05-01. Updated: 2026-11-05.

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

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Linux / Linux: ≥ 5e6c2b4f916157e8f10d093d43e88b2a250d1774; < 1d160dfb3fdf11ba9447e862c548447f91f4e74a (affected, git); ≥ 5e6c2b4f916157e8f10d093d43e88b2a250d1774; < e884a6c2d49a6c12761e5bed851e9fe93bd923a1 (affected, git); ≥ 5e6c2b4f916157e8f10d093d43e88b2a250d1774; < 3acd2016421b2e628acad65495d15493bf7a3bc3 (affected, git); ≥ 5e6c2b4f916157e8f10d093d43e88b2a250d1774; < 4979524f5a2a8210e87fde2f642b0dc060860821 (affected, git). Source: CNA: Linux
- Linux / Linux: 5.9 (affected); ≥ 0; < 5.9 (unaffected, semver); ≥ 5.10.156; ≤ 5.10.* (unaffected, semver); ≥ 5.15.80; ≤ 5.15.* (unaffected, semver); ≥ 6.0.10; ≤ 6.0.* (unaffected, semver); ≥ 6.1; ≤ * (unaffected, original_commit_for_fix). Source: CNA: Linux

## Severity and prioritization

- CISA KEV: No listing in collected sources

- EPSS: 0.22% as of 2026-11-05; percentile 12.20%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: Not reported

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://git.kernel.org/stable/c/1d160dfb3fdf11ba9447e862c548447f91f4e74a (CNA: Linux)

- https://git.kernel.org/stable/c/e884a6c2d49a6c12761e5bed851e9fe93bd923a1 (CNA: Linux)

- https://git.kernel.org/stable/c/3acd2016421b2e628acad65495d15493bf7a3bc3 (CNA: Linux)

- https://git.kernel.org/stable/c/4979524f5a2a8210e87fde2f642b0dc060860821 (CNA: Linux)

## Provenance

- CNA: Linux: https://www.cve.org/CVERecord?id=CVE-2022-49827; retrieved 2026-11-05; source updated 2026-11-05

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2022-49827; retrieved 2026-11-05; source updated Not reported

Revision: 79a9e01ebb8e29bf36cf143653498697204fd4bfbd6a64fea218deccdeaefe43

Canonical: https://y2.dev/cve/CVE-2022-49827

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