Mahesh Salgaonkar

**Name of the Vulnerable Software and Affected Versions** Linux kernel (affected versions not specified) **Description** The issue is related to the powerpc component of the Linux kernel, where the `nmi enter()` and `nmi exit()` functions touch per CPU variables, potentially leading to a kernel crash when invoked during real mode interrupt handling. This can occur if percpu allocation comes from the vmalloc area, particularly when the `CONFIG NEED PER CPU PAGE FIRST CHUNK` is enabled. The vulnerability can be triggered through early HMI/MCE interrupt handlers called via the `DEFINE INTERRUPT HANDLER NMI()` wrapper. Technical details include the involvement of `rcu nmi enter()` and `machine check early()` functions, with specific register values and interrupt handling mechanisms mentioned. **Recommendations** At the moment, there is no information about a newer version that contains a fix for this vulnerability.