Bug 2516488 (CVE-2026-72200)

Summary:	CVE-2026-72200 kernel: ntfs: detect mapping-pairs LCN accumulator overflow
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
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel's NTFS mapping-pairs parser. A corrupted attribute can cause a signed integer overflow when processing Logical Cluster Number (LCN) deltas. This overflow leads to undefined behavior, which may result in the system incorrectly interpreting file system structures. This could potentially lead to data corruption or unauthorized data access.	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 2026-08-15 06:15:09 UTC

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

ntfs: detect mapping-pairs LCN accumulator overflow

The NTFS mapping-pairs parser accumulates relative LCN deltas in a
signed integer.  A corrupted attribute can drive that addition past
the representable range.

One corrupt runlist shape sets the accumulated LCN to S64_MAX and
then adds a delta of 1 in the next mapping-pairs entry.

Signed overflow is undefined and can turn an invalid runlist into a
different set of physical clusters.

Check the LCN addition for overflow before storing the next run.

Comment 1 gkamathe 2026-08-18 13:41:49 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081543-CVE-2026-72200-f14c@gregkh/T