Bug 2356600 (CVE-2025-21956)

Summary:	CVE-2025-21956 kernel: drm/amd/display: Assign normalized_pix_clk when color depth = 14
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:	dfreiber, drow, jburrell, vkumar
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:		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 2025-04-01 16:01:51 UTC

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

drm/amd/display: Assign normalized_pix_clk when color depth = 14

[WHY & HOW]
A warning message "WARNING: CPU: 4 PID: 459 at ... /dc_resource.c:3397
calculate_phy_pix_clks+0xef/0x100 [amdgpu]" occurs because the
display_color_depth == COLOR_DEPTH_141414 is not handled. This is
observed in Radeon RX 6600 XT.

It is fixed by assigning pix_clk * (14 * 3) / 24 - same as the rests.

Also fixes the indentation in get_norm_pix_clk.

(cherry picked from commit 274a87eb389f58eddcbc5659ab0b180b37e92775)

Comment 1 Robb Gatica 2025-04-02 04:38:35 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025040144-CVE-2025-21956-483d@gregkh/T