Bug 2532042 (CVE-2026-89693)

Summary:	CVE-2026-89693 kernel: nfsd: check nfsd4_acl_to_attr() return value in nfsd4_create()
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 Network File System (NFS) daemon, `nfsd`. This vulnerability arises from improper error handling within the `nfsd4_create()` function, which is responsible for creating files and directories. When Access Control Lists (ACLs) are translated, any errors are silently discarded, allowing the creation process to proceed without applying the requested access restrictions. This could lead to an access control bypass, potentially granting unauthorized users unintended access to sensitive resources.	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 2026-09-11 20:14:01 UTC

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

nfsd: check nfsd4_acl_to_attr() return value in nfsd4_create()

nfsd4_create() stores the return value of nfsd4_acl_to_attr() in
status, but the switch(create->cr_type) block unconditionally
overwrites it in every branch. ACL translation errors are silently
discarded, and the CREATE proceeds without the requested ACL.

Add an early exit check after nfsd4_acl_to_attr(), matching the
pattern already used in nfsd4_setattr().

[ cel: prefer NFS4ERR_BADTYPE over NFS4ERR_ATTRNOTSUPP ]

Comment 1 Mauro Matteo Cascella 2026-09-14 15:14:52 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89693.mbox