platform/x86: dell-wmi-sysman: Make populate_foo_data functions more robust

1. Check acpi type before assignment of each property value

2. Add boundary check for properties count
Co-developed-by: Divya Bharathi <divya.bharathi@dell.com>
Signed-off-by: Divya Bharathi <divya.bharathi@dell.com>
Signed-off-by: Prasanth KSR <prasanth.ksr@dell.com>
Link: https://lore.kernel.org/r/20210512102530.9704-1-prasanth.ksr@dell.comReviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/platform/x86/dell/dell-wmi-sysman/dell-wmi-sysman.h

@@ -152,12 +152,15 @@ static ssize_t curr_val##_store(struct kobject *kobj,				\
 	return ret ? ret : count;						\
 }
 
+#define check_property_type(attr, prop, valuetype)				\
+	(attr##_obj[prop].type != valuetype)
+
 union acpi_object *get_wmiobj_pointer(int instance_id, const char *guid_string);
 int get_instance_count(const char *guid_string);
 void strlcpy_attr(char *dest, char *src);
 
 int populate_enum_data(union acpi_object *enumeration_obj, int instance_id,
-			struct kobject *attr_name_kobj);
+			struct kobject *attr_name_kobj, u32 enum_property_count);
 int alloc_enum_data(void);
 void exit_enum_attributes(void);
 

drivers/platform/x86/dell/dell-wmi-sysman/enum-attributes.c

@@ -132,39 +132,68 @@ int alloc_enum_data(void)
  * @enumeration_obj: ACPI object with enumeration data
  * @instance_id: The instance to enumerate
  * @attr_name_kobj: The parent kernel object
+ * @enum_property_count: Total properties count under enumeration type
  */
 int populate_enum_data(union acpi_object *enumeration_obj, int instance_id,
-			struct kobject *attr_name_kobj)
+			struct kobject *attr_name_kobj, u32 enum_property_count)
 {
 	int i, next_obj, value_modifier_count, possible_values_count;
 
 	wmi_priv.enumeration_data[instance_id].attr_name_kobj = attr_name_kobj;
+	if (check_property_type(enumeration, ATTR_NAME, ACPI_TYPE_STRING))
+		return -EINVAL;
 	strlcpy_attr(wmi_priv.enumeration_data[instance_id].attribute_name,
 		enumeration_obj[ATTR_NAME].string.pointer);
+	if (check_property_type(enumeration, DISPL_NAME_LANG_CODE, ACPI_TYPE_STRING))
+		return -EINVAL;
 	strlcpy_attr(wmi_priv.enumeration_data[instance_id].display_name_language_code,
 		enumeration_obj[DISPL_NAME_LANG_CODE].string.pointer);
+	if (check_property_type(enumeration, DISPLAY_NAME, ACPI_TYPE_STRING))
+		return -EINVAL;
 	strlcpy_attr(wmi_priv.enumeration_data[instance_id].display_name,
 		enumeration_obj[DISPLAY_NAME].string.pointer);
+	if (check_property_type(enumeration, DEFAULT_VAL, ACPI_TYPE_STRING))
+		return -EINVAL;
 	strlcpy_attr(wmi_priv.enumeration_data[instance_id].default_value,
 		enumeration_obj[DEFAULT_VAL].string.pointer);
+	if (check_property_type(enumeration, MODIFIER, ACPI_TYPE_STRING))
+		return -EINVAL;
 	strlcpy_attr(wmi_priv.enumeration_data[instance_id].dell_modifier,
 		enumeration_obj[MODIFIER].string.pointer);
 
 	next_obj = MODIFIER + 1;
 
-	value_modifier_count = (uintptr_t)enumeration_obj[next_obj].string.pointer;
+	if (next_obj >= enum_property_count)
+		return -EINVAL;
+
+	if (check_property_type(enumeration, next_obj, ACPI_TYPE_INTEGER))
+		return -EINVAL;
+	value_modifier_count = (uintptr_t)enumeration_obj[next_obj++].string.pointer;
 
 	for (i = 0; i < value_modifier_count; i++) {
+		if (next_obj >= enum_property_count)
+			return -EINVAL;
+		if (check_property_type(enumeration, next_obj, ACPI_TYPE_STRING))
+			return -EINVAL;
 		strcat(wmi_priv.enumeration_data[instance_id].dell_value_modifier,
-			enumeration_obj[++next_obj].string.pointer);
+			enumeration_obj[next_obj++].string.pointer);
 		strcat(wmi_priv.enumeration_data[instance_id].dell_value_modifier, ";");
 	}
 
-	possible_values_count = (uintptr_t) enumeration_obj[++next_obj].string.pointer;
+	if (next_obj >= enum_property_count)
+		return -EINVAL;
+
+	if (check_property_type(enumeration, next_obj, ACPI_TYPE_INTEGER))
+		return -EINVAL;
+	possible_values_count = (uintptr_t) enumeration_obj[next_obj++].string.pointer;
 
 	for (i = 0; i < possible_values_count; i++) {
+		if (next_obj >= enum_property_count)
+			return -EINVAL;
+		if (check_property_type(enumeration, next_obj, ACPI_TYPE_STRING))
+			return -EINVAL;
 		strcat(wmi_priv.enumeration_data[instance_id].possible_values,
-			enumeration_obj[++next_obj].string.pointer);
+			enumeration_obj[next_obj++].string.pointer);
 		strcat(wmi_priv.enumeration_data[instance_id].possible_values, ";");
 	}
 

drivers/platform/x86/dell/dell-wmi-sysman/int-attributes.c

@@ -141,20 +141,36 @@ int populate_int_data(union acpi_object *integer_obj, int instance_id,
 			struct kobject *attr_name_kobj)
 {
 	wmi_priv.integer_data[instance_id].attr_name_kobj = attr_name_kobj;
+	if (check_property_type(integer, ATTR_NAME, ACPI_TYPE_STRING))
+		return -EINVAL;
 	strlcpy_attr(wmi_priv.integer_data[instance_id].attribute_name,
 		integer_obj[ATTR_NAME].string.pointer);
+	if (check_property_type(integer, DISPL_NAME_LANG_CODE, ACPI_TYPE_STRING))
+		return -EINVAL;
 	strlcpy_attr(wmi_priv.integer_data[instance_id].display_name_language_code,
 		integer_obj[DISPL_NAME_LANG_CODE].string.pointer);
+	if (check_property_type(integer, DISPLAY_NAME, ACPI_TYPE_STRING))
+		return -EINVAL;
 	strlcpy_attr(wmi_priv.integer_data[instance_id].display_name,
 		integer_obj[DISPLAY_NAME].string.pointer);
+	if (check_property_type(integer, DEFAULT_VAL, ACPI_TYPE_INTEGER))
+		return -EINVAL;
 	wmi_priv.integer_data[instance_id].default_value =
 		(uintptr_t)integer_obj[DEFAULT_VAL].string.pointer;
+	if (check_property_type(integer, MODIFIER, ACPI_TYPE_STRING))
+		return -EINVAL;
 	strlcpy_attr(wmi_priv.integer_data[instance_id].dell_modifier,
 		integer_obj[MODIFIER].string.pointer);
+	if (check_property_type(integer, MIN_VALUE, ACPI_TYPE_INTEGER))
+		return -EINVAL;
 	wmi_priv.integer_data[instance_id].min_value =
 		(uintptr_t)integer_obj[MIN_VALUE].string.pointer;
+	if (check_property_type(integer, MAX_VALUE, ACPI_TYPE_INTEGER))
+		return -EINVAL;
 	wmi_priv.integer_data[instance_id].max_value =
 		(uintptr_t)integer_obj[MAX_VALUE].string.pointer;
+	if (check_property_type(integer, SCALAR_INCR, ACPI_TYPE_INTEGER))
+		return -EINVAL;
 	wmi_priv.integer_data[instance_id].scalar_increment =
 		(uintptr_t)integer_obj[SCALAR_INCR].string.pointer;
 

drivers/platform/x86/dell/dell-wmi-sysman/passobj-attributes.c

@@ -159,10 +159,16 @@ int alloc_po_data(void)
 int populate_po_data(union acpi_object *po_obj, int instance_id, struct kobject *attr_name_kobj)
 {
 	wmi_priv.po_data[instance_id].attr_name_kobj = attr_name_kobj;
+	if (check_property_type(po, ATTR_NAME, ACPI_TYPE_STRING))
+		return -EINVAL;
 	strlcpy_attr(wmi_priv.po_data[instance_id].attribute_name,
 		     po_obj[ATTR_NAME].string.pointer);
+	if (check_property_type(po, MIN_PASS_LEN, ACPI_TYPE_INTEGER))
+		return -EINVAL;
 	wmi_priv.po_data[instance_id].min_password_length =
 		(uintptr_t)po_obj[MIN_PASS_LEN].string.pointer;
+	if (check_property_type(po, MAX_PASS_LEN, ACPI_TYPE_INTEGER))
+		return -EINVAL;
 	wmi_priv.po_data[instance_id].max_password_length =
 		(uintptr_t) po_obj[MAX_PASS_LEN].string.pointer;
 

drivers/platform/x86/dell/dell-wmi-sysman/string-attributes.c

@@ -118,24 +118,38 @@ int alloc_str_data(void)
 
 /**
  * populate_str_data() - Populate all properties of an instance under string attribute
- * @str_obj: ACPI object with integer data
+ * @str_obj: ACPI object with string data
  * @instance_id: The instance to enumerate
  * @attr_name_kobj: The parent kernel object
  */
 int populate_str_data(union acpi_object *str_obj, int instance_id, struct kobject *attr_name_kobj)
 {
 	wmi_priv.str_data[instance_id].attr_name_kobj = attr_name_kobj;
+	if (check_property_type(str, ATTR_NAME, ACPI_TYPE_STRING))
+		return -EINVAL;
 	strlcpy_attr(wmi_priv.str_data[instance_id].attribute_name,
 		     str_obj[ATTR_NAME].string.pointer);
+	if (check_property_type(str, DISPL_NAME_LANG_CODE, ACPI_TYPE_STRING))
+		return -EINVAL;
 	strlcpy_attr(wmi_priv.str_data[instance_id].display_name_language_code,
 		     str_obj[DISPL_NAME_LANG_CODE].string.pointer);
+	if (check_property_type(str, DISPLAY_NAME, ACPI_TYPE_STRING))
+		return -EINVAL;
 	strlcpy_attr(wmi_priv.str_data[instance_id].display_name,
 		     str_obj[DISPLAY_NAME].string.pointer);
+	if (check_property_type(str, DEFAULT_VAL, ACPI_TYPE_STRING))
+		return -EINVAL;
 	strlcpy_attr(wmi_priv.str_data[instance_id].default_value,
 		     str_obj[DEFAULT_VAL].string.pointer);
+	if (check_property_type(str, MODIFIER, ACPI_TYPE_STRING))
+		return -EINVAL;
 	strlcpy_attr(wmi_priv.str_data[instance_id].dell_modifier,
 		     str_obj[MODIFIER].string.pointer);
+	if (check_property_type(str, MIN_LEN, ACPI_TYPE_INTEGER))
+		return -EINVAL;
 	wmi_priv.str_data[instance_id].min_length = (uintptr_t)str_obj[MIN_LEN].string.pointer;
+	if (check_property_type(str, MAX_LEN, ACPI_TYPE_INTEGER))
+		return -EINVAL;
 	wmi_priv.str_data[instance_id].max_length = (uintptr_t) str_obj[MAX_LEN].string.pointer;
 
 	return sysfs_create_group(attr_name_kobj, &str_attr_group);

drivers/platform/x86/dell/dell-wmi-sysman/sysman.c

@@ -481,7 +481,8 @@ static int init_bios_attributes(int attr_type, const char *guid)
 		/* enumerate all of this attribute */
 		switch (attr_type) {
 		case ENUM:
-			retval = populate_enum_data(elements, instance_id, attr_name_kobj);
+			retval = populate_enum_data(elements, instance_id, attr_name_kobj,
+					obj->package.count);
 			break;
 		case INT:
 			retval = populate_int_data(elements, instance_id, attr_name_kobj);