Bug 2482578 (CVE-2026-46182)

Summary:	CVE-2026-46182 kernel: pseries/papr-hvpipe: Prevent kernel stack memory leak to userspace
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
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
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Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel, specifically within the pseries/papr-hvpipe module. This vulnerability could allow a local user to gain access to uninitialized kernel stack memory. The issue arises because certain padding bytes in a data structure are not cleared before being sent to userspace, potentially leading to the disclosure of sensitive information.	Story Points:	---
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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 2026-05-28 11:04:09 UTC

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

pseries/papr-hvpipe: Prevent kernel stack memory leak to userspace

The hdr variable is allocated on the stack and only hdr.version and
hdr.flags are initialized explicitly. Because the struct papr_hvpipe_hdr
contains reserved padding bytes (reserved[3] and reserved2[40]), these
could leak the uninitialized bytes to userspace after copy_to_user().

This patch fixes that by initializing the whole struct to 0.

Comment 1 Keith Grant 2026-05-28 14:32:10 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026052829-CVE-2026-46182-71eb@gregkh/T