CVE-2026-89921

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.

CVSS

No CVSS.

References

Link	Resource
https://git.kernel.org/stable/c/134f235e0e8de54611a72d3cc3f63e5f31246baa
https://git.kernel.org/stable/c/4e2c7f7cbc27418f9a290399b986c1b85ff93b90
https://git.kernel.org/stable/c/9b046de62b8098af6e2ba820b125ec9dc5f162c8

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-16 11:17

Updated : 2026-09-16 11:17

NVD link : CVE-2026-89921

Mitre link : CVE-2026-89921

CVE.ORG link : CVE-2026-89921

JSON object : View

Products Affected

No product.

CWE

No CWE.

{"id": "CVE-2026-89921", "cveTags": [], "metrics": {}, "affected": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "affectedData": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "383d0b050106abecb82f43101cac94fa423af5cd", "lessThan": "9b046de62b8098af6e2ba820b125ec9dc5f162c8", "versionType": "git"}, {"status": "affected", "version": "383d0b050106abecb82f43101cac94fa423af5cd", "lessThan": "134f235e0e8de54611a72d3cc3f63e5f31246baa", "versionType": "git"}, {"status": "affected", "version": "383d0b050106abecb82f43101cac94fa423af5cd", "lessThan": "4e2c7f7cbc27418f9a290399b986c1b85ff93b90", "versionType": "git"}], "programFiles": ["arch/s390/kvm/kvm-s390.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "3.19"}, {"status": "unaffected", "version": "0", "lessThan": "3.19", "versionType": "semver"}, {"status": "unaffected", "version": "6.18.52", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.2.5", "versionType": "semver", "lessThanOrEqual": "7.2.*"}, {"status": "unaffected", "version": "7.3-rc1", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["arch/s390/kvm/kvm-s390.c"], "defaultStatus": "affected"}]}], "published": "2026-09-16T11:17:01.173", "references": [{"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", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Received", "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."}], "lastModified": "2026-09-16T11:17:01.173", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}