static struct mobj *map_cmd_buffer(paddr_t parg, uint32_t *num_params)
{
	struct mobj *mobj;
	struct optee_msg_arg *arg;
	size_t args_size;

	assert(!(parg & SMALL_PAGE_MASK));
	/* mobj_mapped_shm_alloc checks if parg resides in nonsec ddr */
	mobj = mobj_mapped_shm_alloc(&parg, 1, 0, 0);
	if (!mobj)
		return NULL;

	arg = mobj_get_va(mobj, 0);
	if (!arg) {
		mobj_free(mobj);
		return NULL;
	}

	*num_params = READ_ONCE(arg->num_params);
	args_size = OPTEE_MSG_GET_ARG_SIZE(*num_params);
	if (args_size > SMALL_PAGE_SIZE) {
		EMSG("Command buffer spans across page boundary");
		mobj_free(mobj);
		return NULL;
	}

	return mobj;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.