# CVE-2026-31568: s390/mm: Add missing secure storage access fixups for donated memory

CVE-2026-31568 is fixed in 14 products on 1 platform, first by DEBIAN-CVE-2026-31568, released May 15, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-31568
- Priority: High
- CVSS: 7.1 (Moderate)
- EPSS: 0.0016
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Apr 24, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-31568

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | kernel-64kb sles 15.7 | 6.4.0-150700.53.73.2 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 |
| Linux | kernel-64kb sles 16.0 | 6.12.0-160000.34.1 | [SUSE-SU-2026:22087-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22087-1.md) | Jun 5, 2026 |
| Linux | kernel-azure sles 15.7 | 6.4.0-150700.53.73.2 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 |
| Linux | kernel-azure sles 16.0 | 6.12.0-160000.34.1 | [SUSE-SU-2026:22087-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22087-1.md) | Jun 5, 2026 |
| Linux | kernel-default sles 15.7 | 6.4.0-150700.53.73.2 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 |
| Linux | kernel-default sles 16.0 | 6.12.0-160000.34.1 | [SUSE-SU-2026:22087-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22087-1.md) | Jun 5, 2026 |
| Linux | kernel-default-base sles 15.7 | 6.4.0-150700.53.73.2.150700.17.41.4 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 |
| Linux | kernel-default-base sles 16.0 | 6.12.0-160000.34.1.160000.2.15 | [SUSE-SU-2026:22087-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22087-1.md) | Jun 5, 2026 |
| Linux | kernel-docs sles 15.7 | 6.4.0-150700.53.73.1 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 |
| Linux | kernel-docs sles 16.0 | 6.12.0-160000.34.1 | [SUSE-SU-2026:22087-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22087-1.md) | Jun 5, 2026 |
| Linux | kernel-kvmsmall sles 16.0 | 6.12.0-160000.34.1 | [SUSE-SU-2026:22087-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22087-1.md) | Jun 5, 2026 |
| Linux | kernel-livepatch-SLE15-SP7-RT_Update_18 sles 15.7 | 1-150700.1.5.1 | [SUSE-SU-2026:3130-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3130-1.md) | Jul 20, 2026 |
| Linux | kernel-livepatch-SLE15-SP7_Update_19 sles 15.7 | 1-150700.15.3.4 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 |
| Linux | kernel-obs-build sles 15.7 | 6.4.0-150700.53.73.2 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 |
| Linux | kernel-obs-qa sles 16.0 | 6.12.0-160000.34.1 | [SUSE-SU-2026:22087-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22087-1.md) | Jun 5, 2026 |
| Linux | kernel-source sles 15.7 | 6.4.0-150700.53.73.1 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 |
| Linux | kernel-source sles 16.0 | 6.12.0-160000.34.1 | [SUSE-SU-2026:22087-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22087-1.md) | Jun 5, 2026 |
| Linux | kernel-syms sles 15.7 | 6.4.0-150700.53.73.1 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 |
| Linux | kernel-syms sles 16.0 | 6.12.0-160000.34.1 | [SUSE-SU-2026:22087-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22087-1.md) | Jun 5, 2026 |
| Linux | kernel-zfcpdump sles 15.7 | 6.4.0-150700.53.73.2 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 |
| Linux | kernel-zfcpdump sles 16.0 | 6.12.0-160000.34.1 | [SUSE-SU-2026:22087-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22087-1.md) | Jun 5, 2026 |
| Linux | linux Debian 14 | 6.19.11-1 | [DEBIAN-CVE-2026-31568](https://patchblox.com/security/data/fix/linux/debian-cve-2026-31568.md) | May 15, 2026 |

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Data as of 2026-11-09T07:25:28Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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