Bug 2541142 (CVE-2026-97548)

Summary:	CVE-2026-97548 kernel: xfs: fix the rtrmap and rtrefcount _maxlevels_ondisk functions
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:	akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, 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 XFS file system. A local user can cause a Denial of Service (DoS) or system crash through an out-of-bounds memory access when processing large real-time reverse-mapping or reference count data structures. The issue occurs because the size calculation for in-memory cursor buffers fails to account for the root node level, causing the kernel to allocate insufficient memory and access beyond the end of the buffer.	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 2026-09-25 10:51:47 UTC

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

xfs: fix the rtrmap and rtrefcount _maxlevels_ondisk functions

The _maxlevels_ondisk functions are used to compute the size of
in-memory btree cursors for each btree type.  Unfortunately, LOLLM
noticed that the rtrmap and rtrefcount versions of these functions
forget to account for the inode root, which means that we could access
beyond the end of the cursor given a sufficiently large btree.  Fix
this.

Comment 1 gkamathe 2026-09-28 22:56:35 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97548.mbox