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

s390/mm: Add missing secure storage access fixups for donated memory

There are special cases where secure storage access exceptions happen
in a kernel context for pages that don't have the PG_arch_1 bit
set. That bit is set for non-exported guest secure storage (memory)
but is absent on storage donated to the Ultravisor since the kernel
isn't allowed to export donated pages.

Prior to this patch we would try to export the page by calling
arch_make_folio_accessible() which would instantly return since the
arch bit is absent signifying that the page was already exported and
no further action is necessary. This leads to secure storage access
exception loops which can never be resolved.

With this patch we unconditionally try to export and if that fails we
fixup.

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History

Sat, 25 Apr 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-248
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate


Fri, 24 Apr 2026 15:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: s390/mm: Add missing secure storage access fixups for donated memory There are special cases where secure storage access exceptions happen in a kernel context for pages that don't have the PG_arch_1 bit set. That bit is set for non-exported guest secure storage (memory) but is absent on storage donated to the Ultravisor since the kernel isn't allowed to export donated pages. Prior to this patch we would try to export the page by calling arch_make_folio_accessible() which would instantly return since the arch bit is absent signifying that the page was already exported and no further action is necessary. This leads to secure storage access exception loops which can never be resolved. With this patch we unconditionally try to export and if that fails we fixup.
Title s390/mm: Add missing secure storage access fixups for donated memory
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-04-24T14:35:48.125Z

Reserved: 2026-03-09T15:48:24.117Z

Link: CVE-2026-31568

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-04-24T15:16:31.313

Modified: 2026-04-24T17:51:40.810

Link: CVE-2026-31568

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-04-24T00:00:00Z

Links: CVE-2026-31568 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses