Bug 2535292 (CVE-2026-89823) - CVE-2026-89823 kernel: drm: fix race between partial drm_dev_register() failure and ioctl
Summary: CVE-2026-89823 kernel: drm: fix race between partial drm_dev_register() failu...
Keywords:
Status: NEW
Alias: CVE-2026-89823
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-16 11:54 UTC by OSIDB Bzimport
Modified: 2026-10-23 23:53 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
Environment:
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Description OSIDB Bzimport 2026-09-16 11:54:52 UTC
In the Linux kernel, the following vulnerability has been resolved:

drm: fix race between partial drm_dev_register() failure and ioctl

If drm_dev_register() fails after registering a minor (e.g. render minor
registered, primary minor fails), userspace could have opened the first
minor and entered a drm_dev_enter() critical section. Since the
unplugged flag was never set, the ioctl proceeds while the error path
tears down device resources.

Fix this by introducing drm_dev_synchronize_unplug(), which sets the
unplugged flag and waits for the SRCU barrier, ensuring all in-flight
drm_dev_enter() critical sections complete before cleanup proceeds; call
it on the error path of drm_dev_register().


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