CVE-2026-89921

high

Description

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

https://git.kernel.org/stable/c/9b046de62b8098af6e2ba820b125ec9dc5f162c8

https://git.kernel.org/stable/c/4e2c7f7cbc27418f9a290399b986c1b85ff93b90

https://git.kernel.org/stable/c/134f235e0e8de54611a72d3cc3f63e5f31246baa

Details

Source: Mitre, NVD

Published: 2026-09-16

Updated: 2026-09-16

Risk Information

CVSS v2

Base Score: 6.6

Vector: CVSS2#AV:L/AC:L/Au:N/C:C/I:N/A:C

Severity: Medium

CVSS v3

Base Score: 7.1

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Severity: High

EPSS

EPSS: 0.00198