ima: Fix misuse of dereference of pointer in template_desc_init_fields()

The input parameter @fields is type of struct ima_template_field ***, so
when allocates array memory for @fields, the size of element should be
sizeof(**field) instead of sizeof(*field).

Actually the original code would not cause any runtime error, but it's
better to make it logically right.

Fixes: adf53a77 ("ima: new templates management mechanism")
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

security/integrity/ima/ima_template.c

@@ -245,11 +245,11 @@ int template_desc_init_fields(const char *template_fmt,
 	}
 
 	if (fields && num_fields) {
-		*fields = kmalloc_array(i, sizeof(*fields), GFP_KERNEL);
+		*fields = kmalloc_array(i, sizeof(**fields), GFP_KERNEL);
 		if (*fields == NULL)
 			return -ENOMEM;
 
-		memcpy(*fields, found_fields, i * sizeof(*fields));
+		memcpy(*fields, found_fields, i * sizeof(**fields));
 		*num_fields = i;
 	}