FKIE_CVE-2026-89921

Vulnerability from fkie_nvd - Published: 2026-09-16 11:17 - Updated: 2026-09-16 11:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: KVM: s390: Zero initialize data structures for inject_pfault_token __kvm_inject_pfault_token() only sets .type and .u.ext.ext_params2 of the on-stack struct kvm_s390_irq but the full ext substructure is copied into the cpu local variable on inject. ext_params and pad contain stale stack values. Interrupt delivery only uses ext_params2, so nothing leaks to the guest, but a host user can use the migration ioctls to get to the data. Fix by zero-initializing the irq struct. Do the same for the inti data structure.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/134f235e0e8de54611a72d3cc3f63e5f31246baa
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4e2c7f7cbc27418f9a290399b986c1b85ff93b90
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/9b046de62b8098af6e2ba820b125ec9dc5f162c8
Impacted products
Vendor Product Version
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{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/s390/kvm/kvm-s390.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "9b046de62b8098af6e2ba820b125ec9dc5f162c8",
              "status": "affected",
              "version": "383d0b050106abecb82f43101cac94fa423af5cd",
              "versionType": "git"
            },
            {
              "lessThan": "134f235e0e8de54611a72d3cc3f63e5f31246baa",
              "status": "affected",
              "version": "383d0b050106abecb82f43101cac94fa423af5cd",
              "versionType": "git"
            },
            {
              "lessThan": "4e2c7f7cbc27418f9a290399b986c1b85ff93b90",
              "status": "affected",
              "version": "383d0b050106abecb82f43101cac94fa423af5cd",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/s390/kvm/kvm-s390.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.19"
            },
            {
              "lessThan": "3.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.52",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: s390: Zero initialize data structures for inject_pfault_token\n\n__kvm_inject_pfault_token() only sets .type and .u.ext.ext_params2 of\nthe on-stack struct kvm_s390_irq but the full ext substructure is copied\ninto the cpu local variable on inject. ext_params and pad contain stale\nstack values.\n\nInterrupt delivery only uses ext_params2, so nothing leaks to the guest,\nbut a host user can use the migration ioctls to get to the data.\n\nFix by zero-initializing the irq struct.\nDo the same for the inti data structure."
    }
  ],
  "id": "CVE-2026-89921",
  "lastModified": "2026-09-16T11:17:01.173",
  "metrics": {},
  "published": "2026-09-16T11:17:01.173",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/134f235e0e8de54611a72d3cc3f63e5f31246baa"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4e2c7f7cbc27418f9a290399b986c1b85ff93b90"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9b046de62b8098af6e2ba820b125ec9dc5f162c8"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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