Bug 2546452 (CVE-2026-98267)

Summary:	CVE-2026-98267 kernel: 9p: Fix v9fs_issue_write() to update i_size and remote_i_size
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 9P file system implementation. When write operations extend a file, the kernel fails to update the recorded file size to reflect the new length. A local user performing write operations on a 9P mount can trigger this issue, leading to inconsistent file state tracking. This flaw can result in unexpected application errors or potential data corruption.	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 2026-10-06 09:22:47 UTC

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

9p: Fix v9fs_issue_write() to update i_size and remote_i_size

Fix v9fs_issue_write() to update i_size and remote_i_size to the new size
of the server file if we made it larger, using the start fpos and the count
returned by p9_client_write() to calculate the new minimum file size.

This assumes that if the 9P server makes a short write (say it hits
ENOSPC), a reduced count is returned.

Comment 1 gkamathe 2026-10-10 20:05:14 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98267.mbox