Bug 2481998 (CVE-2026-45955)

Summary:	CVE-2026-45955 kernel: md/md-llbitmap: fix percpu_ref not resurrected on suspend timeout
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
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's `md/md-llbitmap` component. This vulnerability occurs when a suspend operation times out, failing to properly reset a critical internal reference. This oversight leaves the system's page control structure in an unusable state. This issue can lead to system instability or a Denial of Service (DoS), where the system becomes unresponsive.	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 2026-05-27 15:06:18 UTC

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

md/md-llbitmap: fix percpu_ref not resurrected on suspend timeout

When llbitmap_suspend_timeout() times out waiting for percpu_ref to
become zero, it returns -ETIMEDOUT without resurrecting the percpu_ref.
The caller (md_llbitmap_daemon_fn) then continues to the next page
without calling llbitmap_resume(), leaving the percpu_ref in a killed
state permanently.

Fix this by resurrecting the percpu_ref before returning the error,
ensuring the page control structure remains usable for subsequent
operations.

Comment 1 Keith Grant 2026-05-27 23:33:33 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026052732-CVE-2026-45955-00bf@gregkh/T