Bug 2541050 (CVE-2026-98024)

Summary:	CVE-2026-98024 kernel: s390/ism: folio_put() after error
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 s390 Internal Shared Memory (ISM) driver. This flaw allows a local user to cause a Denial of Service (DoS) due to memory corruption. During an error condition while allocating direct memory buffers, the driver incorrectly frees memory pages using an improper deallocation function. This mishandling corrupts kernel slab memory and can lead to a system crash.	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 2026-09-25 10:44:58 UTC

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

s390/ism: folio_put() after error

dmb->cpu_addr was allocated via folio_alloc(). Use folio_put() instead of
kfree() in the error exit of ism_alloc_dmb() to avoid slab allocator
corruption.

While at it, reset dmb->cpu_addr after folio_put to avoid unintentional UAF
by future callers.

Comment 1 Keith Grant 2026-09-28 21:14:27 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98024.mbox