CVE-2026-63863: drm/gpusvm: Fix unbalanced unlock in drm_gpusvm_scan_mm()

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-19 · updated 2026-10-26
Weakness: CWE-667

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.

Affected products

Linux kernel: from 7.0 before 7.0.10 — fixed in 7.0.10
Linux kernel: 7.0 — fixed in 7.1

How to fix

Upgrade to a fixed version: Linux kernel 7.0.10; Linux kernel 7.1. Check the vendor advisory for mitigations.

References

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