CVE-2026-89921 (GCVE-0-2026-89921)

Vulnerability from cvelistv5 – Published: 2026-09-16 10:32 – Updated: 2026-09-16 10:32
VLAI
Title
KVM: s390: Zero initialize data structures for inject_pfault_token
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.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 383d0b050106abecb82f43101cac94fa423af5cd , < 9b046de62b8098af6e2ba820b125ec9dc5f162c8 (git)
Affected: 383d0b050106abecb82f43101cac94fa423af5cd , < 134f235e0e8de54611a72d3cc3f63e5f31246baa (git)
Affected: 383d0b050106abecb82f43101cac94fa423af5cd , < 4e2c7f7cbc27418f9a290399b986c1b85ff93b90 (git)
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Linux Linux Affected: 3.19
Unaffected: 0 , < 3.19 (semver)
Unaffected: 6.18.52 , ≤ 6.18.* (semver)
Unaffected: 7.2.5 , ≤ 7.2.* (semver)
Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)
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{
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          "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."
        }
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      "providerMetadata": {
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    "dateReserved": "2026-09-11T19:38:34.775Z",
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            "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",
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        "vulnStatus": "Received"
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}



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