Bug 2513147 (CVE-2026-68303)

Summary:	CVE-2026-68303 kernel: drm/vc4: hvs/v3d: Fix null dereference in unbind
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability-draft	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	unspecified	CC:	rhel-process-autobot, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel's drm/vc4 drivers, specifically in the hvs and v3d components. When these drivers are being removed, they attempt to access memory that has already been freed. This occurs because they try to retrieve driver data from a master device that is no longer available, leading to a null pointer dereference. A local attacker could potentially exploit this vulnerability to cause system instability or a denial of service (DoS).	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-08-10 12:21:47 UTC

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

drm/vc4: hvs/v3d: Fix null dereference in unbind

The hvs and v3d drivers use dev_get_drvdata(master) in their unbind
functions. Since the vc4-drm gets removed before its dependent drivers
(vc4_hvs/vc4_v3d) the vc4_hvs_unbind/vc4_v3d_unbind functions try to
get drvdata of its master and fails with a null dereference error.

Use the data pointer passed to the unbind functions directly instead of
dev_get_drvdata(master). This avoids using potentially freed memory.

Comment 1 gkamathe 2026-08-11 10:56:57 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081030-CVE-2026-68303-7d13@gregkh/T