drivers: virt: acrn: hsm: Use kzalloc to avoid info leak in pmcmd_ioctl

In the Linux kernel, the following vulnerability has been resolved:

drivers: virt: acrn: hsm: Use kzalloc to avoid info leak in pmcmd_ioctl

In the "pmcmd_ioctl" function, three memory objects allocated by

kmalloc are initialized by "hcall_get_cpu_state", which are then

copied to user space. The initializer is indeed implemented in

"acrn_hypercall2" (arch/x86/include/asm/acrn.h). There is a risk of

information leakage due to uninitialized bytes.