Bug 2461534 (CVE-2026-31671)

Summary:	CVE-2026-31671 kernel: xfrm_user: fix info leak in build_report()
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's xfrm_user component. This vulnerability allows a local attacker to disclose sensitive information. The xfrm_user_report structure contains uninitialized padding bytes that are copied to userspace, leading to an information leak.	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 2026-04-24 15:07:05 UTC

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

xfrm_user: fix info leak in build_report()

struct xfrm_user_report is a __u8 proto field followed by a struct
xfrm_selector which means there is three "empty" bytes of padding, but
the padding is never zeroed before copying to userspace.  Fix that up by
zeroing the structure before setting individual member variables.

Comment 1 Keith Grant 2026-04-24 22:41:15 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026042407-CVE-2026-31671-c4b9@gregkh/T