CVE-2026-31568
s390/mm: Add missing secure storage access fixups for donated memory
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.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| Linux Linux |
≥ 084ea4d611a3d00ee3930400b262240e10895900; < 48eda93e50f8361dee8e261fe55d0b31714e1e56 (affected, git) ≥ 084ea4d611a3d00ee3930400b262240e10895900; < 1eb35c54cd81cf874ce7d69e3dbfb162f211b8bd (affected, git) ≥ 084ea4d611a3d00ee3930400b262240e10895900; < b36b0e804aee5f20c6798dbeaeaa7cfdb7c6cf88 (affected, git) ≥ 084ea4d611a3d00ee3930400b262240e10895900; < 43ac2d18db1131df0a89993f709131ebfc29f3bd (affected, git) ≥ 084ea4d611a3d00ee3930400b262240e10895900; < b00be77302d7ec4ad0367bb236494fce7172b730 (affected, git) Other versions: unaffected |
CNA: Linux |
| Linux Linux |
5.7 (affected) ≥ 0; < 5.7 (unaffected, semver) ≥ 6.1.191; ≤ 6.1.* (unaffected, semver) ≥ 6.6.160; ≤ 6.6.* (unaffected, semver) ≥ 6.18.21; ≤ 6.18.* (unaffected, semver) ≥ 6.19.11; ≤ 6.19.* (unaffected, semver) ≥ 7.0; ≤ * (unaffected, original_commit_for_fix) Other versions: affected |
CNA: Linux |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
No CVSS assessment reported. An unscored record is not a low-severity determination.
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://git.kernel.org/stable/c/48eda93e50f8361dee8e261fe55d0b31714e1e56CNA: Linux
- https://git.kernel.org/stable/c/1eb35c54cd81cf874ce7d69e3dbfb162f211b8bdCNA: Linux
- https://git.kernel.org/stable/c/b36b0e804aee5f20c6798dbeaeaa7cfdb7c6cf88CNA: Linux
- https://git.kernel.org/stable/c/43ac2d18db1131df0a89993f709131ebfc29f3bdCNA: Linux
- https://git.kernel.org/stable/c/b00be77302d7ec4ad0367bb236494fce7172b730CNA: Linux
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