Bug 2555153 (CVE-2026-98727)

Summary:	CVE-2026-98727 kernel: nvme-multipath: set BLK_FEAT_ZONED only after the zone info is known
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 NVMe (Non-Volatile Memory Express) multipath subsystem. The multipath driver inappropriately marks a storage device as supporting zoned storage before confirming its zone configuration. When a device reports a zone size of zero, subsequent read or write operations attempt an invalid mathematical shift calculation. A local user interacting with the affected storage device can exploit this flaw to crash the system, resulting in a Denial of Service (DoS).	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 2026-10-18 15:57:25 UTC

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

nvme-multipath: set BLK_FEAT_ZONED only after the zone info is known

The namespace head is marked zoned at allocation time based only on the
command set identifier.  If the zone info query reports a zero zone size,
the path namespace is registered without zoned limits while the head
still advertises the zoned capability with a zone size of zero, and
reporting zones or writing to the head then shifts by ilog2(0).

Drop the zoned feature from the head allocation and let the head limits
refresh stack it in from the path namespace instead.

Comment 1 Mauro Matteo Cascella 2026-10-22 23:30:55 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98727.mbox