Bug 2535168 (CVE-2026-89820)

Summary:	CVE-2026-89820 kernel: drm/amd/display: fix dc_lock leak on GPU reset error paths
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
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Doc Text:	A flaw was found in the Linux kernel's `drm/amd/display` component. During a GPU reset, if certain functions fail after acquiring a `dc_lock`, the lock is not properly released. This can lead to a `dc_lock` leak, causing subsequent attempts to acquire the lock to hang, resulting in a Denial of Service (DoS) for the system.	Story Points:	---
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Last Closed:		Type:	---
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Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-09-16 11:05:39 UTC

In the Linux kernel, the following vulnerability has been resolved:

drm/amd/display: fix dc_lock leak on GPU reset error paths

On GPU reset, dm_suspend() takes dc_lock and leaves it for dm_resume()
to drop. If amdgpu_dm_commit_zero_streams() or dm_dmub_hw_init() fails,
the function returns with the lock still held. The matching resume path
is then skipped, so every later dc_lock take hangs.

Release the cached DC state and unlock before returning the error.

Comment 1 Mauro Matteo Cascella 2026-09-21 16:51:45 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89820.mbox