platform/x86: hp-bioscfg: Fix out-of-bounds array access in ACPI package parsing

The hp_populate_*_elements_from_package() functions in the hp-bioscfg
driver contain out-of-bounds array access vulnerabilities.

These functions parse ACPI packages into internal data structures using
a for loop with index variable 'elem' that iterates through
enum_obj/integer_obj/order_obj/password_obj/string_obj arrays.

When processing multi-element fields like PREREQUISITES and
ENUM_POSSIBLE_VALUES, these functions read multiple consecutive array
elements using expressions like 'enum_obj[elem + reqs]' and
'enum_obj[elem + pos_values]' within nested loops.

The bug is that the bounds check only validated elem, but did not consider
the additional offset when accessing elem + reqs or elem + pos_values.

The fix changes the bounds check to validate the actual accessed index.

Reported-by: Yuhao Jiang <danisjiang@gmail.com>
Reported-by: Junrui Luo <moonafterrain@outlook.com>
Fixes: e6c7b3e ("platform/x86: hp-bioscfg: string-attributes")
Signed-off-by: Junrui Luo <moonafterrain@outlook.com>
Link: https://patch.msgid.link/SYBPR01MB788173D7DD4EA2CB6383683DAFB0A@SYBPR01MB7881.ausprd01.prod.outlook.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

Author: avasummer

drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c

@@ -207,7 +207,7 @@ static int hp_populate_enumeration_elements_from_package(union acpi_object *enum
 		case PREREQUISITES:
 			size = min_t(u32, enum_data->common.prerequisites_size, MAX_PREREQUISITES_SIZE);
 			for (reqs = 0; reqs < size; reqs++) {
-				if (elem >= enum_obj_count) {
+				if (elem + reqs >= enum_obj_count) {
 					pr_err("Error enum-objects package is too small\n");
 					return -EINVAL;
 				}
@@ -255,7 +255,7 @@ static int hp_populate_enumeration_elements_from_package(union acpi_object *enum
 
 			for (pos_values = 0; pos_values < size && pos_values < MAX_VALUES_SIZE;
 			     pos_values++) {
-				if (elem >= enum_obj_count) {
+				if (elem + pos_values >= enum_obj_count) {
 					pr_err("Error enum-objects package is too small\n");
 					return -EINVAL;
 				}

drivers/platform/x86/hp/hp-bioscfg/int-attributes.c

@@ -227,7 +227,7 @@ static int hp_populate_integer_elements_from_package(union acpi_object *integer_
 			size = min_t(u32, integer_data->common.prerequisites_size, MAX_PREREQUISITES_SIZE);
 
 			for (reqs = 0; reqs < size; reqs++) {
-				if (elem >= integer_obj_count) {
+				if (elem + reqs >= integer_obj_count) {
 					pr_err("Error elem-objects package is too small\n");
 					return -EINVAL;
 				}

drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c

@@ -216,6 +216,11 @@ static int hp_populate_ordered_list_elements_from_package(union acpi_object *ord
 			size = min_t(u32, ordered_list_data->common.prerequisites_size,
 				     MAX_PREREQUISITES_SIZE);
 			for (reqs = 0; reqs < size; reqs++) {
+				if (elem + reqs >= order_obj_count) {
+					pr_err("Error elem-objects package is too small\n");
+					return -EINVAL;
+				}
+
 				ret = hp_convert_hexstr_to_str(order_obj[elem + reqs].string.pointer,
 							       order_obj[elem + reqs].string.length,
 							       &str_value, &value_len);

drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c

@@ -303,6 +303,11 @@ static int hp_populate_password_elements_from_package(union acpi_object *passwor
 				     MAX_PREREQUISITES_SIZE);
 
 			for (reqs = 0; reqs < size; reqs++) {
+				if (elem + reqs >= password_obj_count) {
+					pr_err("Error elem-objects package is too small\n");
+					return -EINVAL;
+				}
+
 				ret = hp_convert_hexstr_to_str(password_obj[elem + reqs].string.pointer,
 							       password_obj[elem + reqs].string.length,
 							       &str_value, &value_len);

drivers/platform/x86/hp/hp-bioscfg/string-attributes.c

@@ -217,7 +217,7 @@ static int hp_populate_string_elements_from_package(union acpi_object *string_ob
 				     MAX_PREREQUISITES_SIZE);
 
 			for (reqs = 0; reqs < size; reqs++) {
-				if (elem >= string_obj_count) {
+				if (elem + reqs >= string_obj_count) {
 					pr_err("Error elem-objects package is too small\n");
 					return -EINVAL;
 				}