Linux · Linux Kernel · CVE-2024-45005
**Name of the Vulnerable Software and Affected Versions**
Linux kernel versions prior to 6.6.50
**Description**
The issue is related to a validity interception problem in the KVM (Kernel-based Virtual Machine) component of the Linux kernel when the gisa (Guest Interrupt Specification Architecture) is switched off. This can occur either by using the kernel parameter "kvm.use gisa=0" or by setting the related sysfs attribute to N. The problem arises because an uninitialized gisa origin is passed to the `virt to phys()` function before being written to the gisa designation in the SIE (System Interrupt Executor) control block. To fix this, the `kvm s390 get gisa desc()` function now returns 0 if the origin is 0, which determines the gisa designation to set in the SIE control block and disables gisa usage when the designation is 0.
**Recommendations**
To resolve the issue, update the Linux kernel to version 6.6.50 or later. As a temporary workaround, consider disabling the gisa usage by setting the kernel parameter "kvm.use gisa=0" or the related sysfs attribute to N until a patch is available.