CVE-2021-47465

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description The issue is related to the KVM: PPC: Book3S HV: Fix stack handling in idle kvm start guest() function. The problem arises because there is no caller frame on the emergency stack, and the function stores CR/LR into its caller's frame, which can lead to corruption of memory outside the allocation for the emergency stack. The function creates a stack frame and saves non-volatile registers, but the frame is not large enough to fit the non-volatiles, resulting in writing outside the emergency stack allocation. This can corrupt memory at 0-24 bytes and 112-248 bytes above the emergency stack allocation. However, this has gone unnoticed in practice because the memory immediately above the emergency stack is used for other stack allocations.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.