crypto: ccp - Use kzalloc for sev ioctl interfaces to prevent kernel memory leak

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

crypto: ccp - Use kzalloc for sev ioctl interfaces to prevent kernel memory leak

For some sev ioctl interfaces, input may be passed that is less than or

equal to SEV_FW_BLOB_MAX_SIZE, but larger than the data that PSP

firmware returns. In this case, kmalloc will allocate memory that is the

size of the input rather than the size of the data. Since PSP firmware

doesn't fully overwrite the buffer, the sev ioctl interfaces with the

issue may return uninitialized slab memory.

Currently, all of the ioctl interfaces in the ccp driver are safe, but

to prevent future problems, change all ioctl interfaces that allocate

memory with kmalloc to use kzalloc and memset the data buffer to zero

in sev_ioctl_do_platform_status.