KVM: s390: Fix memory corruption by not reinjecting CK machine checks
Summary
| CVE | CVE-2026-89920 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-16 11:17:01 UTC |
| Updated | 2026-10-21 13:20:31 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: KVM: s390: Fix memory corruption by not reinjecting CK machine checks Channel-subsystem damage machine checks are for the host channel subsystem. The guest channel subsystem is emulated in the userspace VMM. There is no point in forwarding such machine checks into the guest. This also simplifies the machine check reinjection and avoids kfree of a stack variable as reported by sashiko. There might be still machine checks that have the ck bit set with another bit (like instruction damage), mask out the CK bit in s390_backup_mcck_info(), like the CP and ED bits already are. |
Risk And Classification
Primary CVSS: v3.1 7.8 HIGH from 416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | Secondary | 7.8 | HIGH | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H |
| 3.1 | CNA | DECLARED | 7.8 | HIGH | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
HighPrivileges Required
LowUser Interaction
NoneScope
ChangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 4d62fcc0b692e3b4058d7d138114c27cd8b011f7 5c63e2ed840c85e27172ab78e7db3ac77fba281b git | Not specified |
| CNA | Linux | Linux | affected 4d62fcc0b692e3b4058d7d138114c27cd8b011f7 b7631982fb65dd355acd18e62b384bc8125e9c44 git | Not specified |
| CNA | Linux | Linux | affected 4d62fcc0b692e3b4058d7d138114c27cd8b011f7 6ee52d3af2a1bf70349cf3f860933c8d221e229a git | Not specified |
| CNA | Linux | Linux | affected 4d62fcc0b692e3b4058d7d138114c27cd8b011f7 7077ec953996acc04b49d1dfc43df1c1a2a74395 git | Not specified |
| CNA | Linux | Linux | affected 4d62fcc0b692e3b4058d7d138114c27cd8b011f7 546dde823a36d7283dcf46127c2f3d093443860f git | Not specified |
| CNA | Linux | Linux | affected 4.13 | Not specified |
| CNA | Linux | Linux | unaffected 4.13 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.160 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.114 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.51 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2.5 7.2.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.3 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/b7631982fb65dd355acd18e62b384bc8125e9c44 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/5c63e2ed840c85e27172ab78e7db3ac77fba281b | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/7077ec953996acc04b49d1dfc43df1c1a2a74395 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/546dde823a36d7283dcf46127c2f3d093443860f | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/6ee52d3af2a1bf70349cf3f860933c8d221e229a | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.