Bug 2513415 (CVE-2026-68107)

Summary:	CVE-2026-68107 kernel: drm/amdgpu/vcn4: avoid rereading IB param length
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
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:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel. Specifically, within the `drm/amdgpu/vcn4` component, a time-of-check to time-of-use (TOCTOU) vulnerability exists. This occurs because the system re-reads the IB parameter length instead of reusing an already obtained value. This could allow a local attacker to potentially manipulate the IB contents between reads, leading to unexpected behavior or a denial of service.	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 12:36:06 UTC

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

drm/amdgpu/vcn4: avoid rereading IB param length

Reuse the parameter length returned by
vcn_v4_0_enc_find_ib_param() instead of rereading it from
the IB.

This avoids a potential TOCTOU issue if the IB contents
change between reads.

(cherry picked from commit dbb02b4755f8c1f3773263f2d779872c1c0c073a)

Comment 1 Mauro Matteo Cascella 2026-08-11 16:35:17 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081053-CVE-2026-68107-cb95@gregkh/T