Bug 2535140 (CVE-2026-89972)

Summary:	CVE-2026-89972 kernel: nvme: add missing SRCU grace period in error path
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
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 NVMe (Non-Volatile Memory Express) driver of the Linux kernel. The nvme_alloc_ns() function's error handling path fails to wait for all SRCU (Sleepable Read-Copy Update) readers to complete before freeing a namespace structure. This oversight allows a concurrent reader to access a freed memory region, leading to a use-after-free vulnerability. A local attacker could potentially exploit this to cause a system crash or achieve arbitrary code execution.	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 2026-09-16 10:58:13 UTC

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

nvme: add missing SRCU grace period in error path

nvme_alloc_ns() error path at out_unlink_ns removes ns from the
namespace head siblings list with list_del_rcu(&ns->siblings) but
does not wait for SRCU readers before freeing the namespace struct.
Multipath code iterates the head->list under srcu_read_lock() in
nvme_find_path() and nvme_mpath_revalidate_paths(), so a concurrent
reader can still hold a reference to ns when kfree(ns) runs.

The normal removal path in nvme_ns_remove() correctly calls
synchronize_srcu(&ns->head->srcu) after list_del_rcu() to wait for
in-progress readers. Add the same grace period in the error path.

Comment 1 Keith Grant 2026-09-16 19:30:16 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89972.mbox

Comment 3 Jon Orris 2026-10-05 10:48:57 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:75746 https://access.redhat.com/errata/RHSA-2026:75746

Comment 4 Jon Orris 2026-10-05 11:24:06 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:75747 https://access.redhat.com/errata/RHSA-2026:75747

Comment 5 Jon Orris 2026-10-07 20:28:50 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:76738 https://access.redhat.com/errata/RHSA-2026:76738

Comment 6 Jon Orris 2026-10-08 09:50:32 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:76739 https://access.redhat.com/errata/RHSA-2026:76739