CVE-2026-89920

Full vulnerability record from the local CVENow database.

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.

Severity

HIGH

CVSS score

7.8 (v3.1)

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-09-16 11:17:01.073000

Last modified

2026-10-30 13:20:35.690000

View original CVE JSON

{
  "id": "CVE-2026-89920",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-16T11:17:01.073",
  "lastModified": "2026-10-30T13:20:35.690",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: s390: Fix memory corruption by not reinjecting CK machine checks\n\nChannel-subsystem damage machine checks are for the host channel\nsubsystem. The guest channel subsystem is emulated in the userspace VMM.\nThere is no point in forwarding such machine checks into the guest.\n\nThis also simplifies the machine check reinjection and avoids kfree of a\nstack variable as reported by sashiko.  There might be still machine\nchecks that have the ck bit set with another bit (like instruction\ndamage), mask out the CK bit in s390_backup_mcck_info(), like the CP and\nED bits already are."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "arch/s390/include/asm/nmi.h",
            "arch/s390/kernel/nmi.c",
            "arch/s390/kvm/interrupt.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "4d62fcc0b692e3b4058d7d138114c27cd8b011f7",
              "lessThan": "045f3e95a0deccb277c29bd003e1d43c0ad40c90",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4d62fcc0b692e3b4058d7d138114c27cd8b011f7",
              "lessThan": "5c63e2ed840c85e27172ab78e7db3ac77fba281b",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4d62fcc0b692e3b4058d7d138114c27cd8b011f7",
              "lessThan": "b7631982fb65dd355acd18e62b384bc8125e9c44",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4d62fcc0b692e3b4058d7d138114c27cd8b011f7",
              "lessThan": "6ee52d3af2a1bf70349cf3f860933c8d221e229a",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4d62fcc0b692e3b4058d7d138114c27cd8b011f7",
              "lessThan": "7077ec953996acc04b49d1dfc43df1c1a2a74395",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4d62fcc0b692e3b4058d7d138114c27cd8b011f7",
              "lessThan": "546dde823a36d7283dcf46127c2f3d093443860f",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "arch/s390/include/asm/nmi.h",
            "arch/s390/kernel/nmi.c",
            "arch/s390/kvm/interrupt.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "4.13",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "4.13",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.191",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.160",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.114",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.51",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.5",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "HIGH",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "CHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.1,
        "impactScore": 6.0
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/045f3e95a0deccb277c29bd003e1d43c0ad40c90",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/546dde823a36d7283dcf46127c2f3d093443860f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/5c63e2ed840c85e27172ab78e7db3ac77fba281b",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/6ee52d3af2a1bf70349cf3f860933c8d221e229a",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/7077ec953996acc04b49d1dfc43df1c1a2a74395",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b7631982fb65dd355acd18e62b384bc8125e9c44",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}