Bug 2461569 (CVE-2026-31628)

Summary:	CVE-2026-31628 kernel: x86/CPU: Fix FPDSS on Zen1
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:	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. On systems utilizing Zen1 processors, the hardware divider can, under specific conditions, retain partial results from prior operations. A local attacker can exploit this vulnerability to access these residual results, leading to information disclosure.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
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Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-04-24 15:08:59 UTC

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

x86/CPU: Fix FPDSS on Zen1

Zen1's hardware divider can leave, under certain circumstances, partial
results from previous operations.  Those results can be leaked by
another, attacker thread.

Fix that with a chicken bit.

Comment 1 Keith Grant 2026-04-24 20:39:04 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026042428-CVE-2026-31628-8187@gregkh/T