Bug 2521360 (CVE-2026-74730)

Summary:	CVE-2026-74730 kernel: NFS: Pin the 'struct nfs_server' during a FREE_STATEID call
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 Network File System (NFS). This vulnerability involves improper memory handling where a critical data structure is released prematurely if a `FREE_STATEID` operation is delayed. This can lead to memory corruption, potentially causing system instability or a denial of service.	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 2026-08-22 15:41:42 UTC

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

NFS: Pin the 'struct nfs_server' during a FREE_STATEID call

Dan Aloni reports that he was able to hit a use-after-free bug if a
FREE_STATEID operation gets delayed for whatever reason. Fix this by
bumping the refcount of the 'struct nfs_server' object for the duration
of the FREE_STATEID so it doesn't get cleaned up from underneath us
while operations are still in flight.

Comment 1 gkamathe 2026-08-24 06:56:12 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026082242-CVE-2026-74730-e35d@gregkh/T