Bug 2513280 (CVE-2026-68154)

Summary:	CVE-2026-68154 kernel: libceph: reject zero bucket types in crush_decode
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
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 `libceph` component. A remote attacker could provide a specially crafted CRUSH map with a zero bucket type. This malformed map could cause the system to treat a negative bucket ID as a device, leading to an out-of-bounds access when indexing the OSD weight array. This could result in 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 2026-08-10 12:28:41 UTC

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

libceph: reject zero bucket types in crush_decode

CRUSH bucket type 0 is reserved for devices.  The mapper relies on
that invariant and uses type 0 to identify leaf devices.

If crush_decode() accepts a bucket with type 0, a malformed CRUSH map
can make the mapper treat a negative bucket ID as a device and pass it
to is_out(), which then indexes the OSD weight array with a negative
value.

Reject zero bucket types while decoding the CRUSH map so the invalid
state never reaches the mapper.