* [PATCH v5 1/4] platform/x86: hp-bioscfg: pass validated element count to package parsers
2026-07-09 16:58 [PATCH v5 0/4] platform/x86: hp-bioscfg: fix ACPI package handling on HP EliteBook 840 G2 Muhammad Bilal
@ 2026-07-09 16:58 ` Muhammad Bilal
2026-07-09 16:58 ` [PATCH v5 2/4] platform/x86: hp-bioscfg: bound ordered-list parsing by the package count Muhammad Bilal
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Muhammad Bilal @ 2026-07-09 16:58 UTC (permalink / raw)
To: Hans de Goede, Ilpo Järvinen, Jorge Lopez,
Thomas Weißschuh, platform-driver-x86, linux-kernel
Cc: stable, Mario Limonciello, Armin Wolf, Muhammad Bilal
The per-type package parsers are handed the wrong element count.
hp_init_bios_package_attribute() validates obj->package.count and then
calls one of the five hp_populate_*_package_data() wrappers (string,
integer, enumeration, ordered list, password). Each wrapper forwards a
count to its hp_populate_*_elements_from_package() parser, but instead
of forwarding the validated obj->package.count it derives the count
from elements[0]. elements[0] is the NAME field and is always an
ACPI_TYPE_STRING, so reading ->package.count from it in fact reads
->string.length through the union acpi_object. The parsers thus bound
themselves against the length of the name string rather than against
the real number of elements in the package.
This is safe today because hp_init_bios_package_attribute() refuses any
package that has fewer than the type's element count, so a parser only
ever runs on a full package and never reads past it regardless of the
bogus bound.
An upcoming change relaxes that check to accept shorter packages. Once
a parser can receive fewer elements than its per-type count, a bound
taken from the name length no longer reflects the array size, and the
"elem < count" loop conditions and "elem + n >= count" sub-loop guards
read past the end of elements[] - an out-of-bounds heap read.
Forward the validated obj->package.count to every *_package_data()
wrapper so the parsers bound themselves against the real package size.
This does not change behaviour for the packages that enumerate
correctly today and is a prerequisite for accepting shorter packages
safely.
Cc: stable@vger.kernel.org
Signed-off-by: Muhammad Bilal <meatuni001@gmail.com>
---
drivers/platform/x86/hp/hp-bioscfg/bioscfg.c | 5 +++++
drivers/platform/x86/hp/hp-bioscfg/bioscfg.h | 5 +++++
drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c | 4 +++-
drivers/platform/x86/hp/hp-bioscfg/int-attributes.c | 4 +++-
drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c | 6 ++++--
drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c | 6 ++++--
drivers/platform/x86/hp/hp-bioscfg/string-attributes.c | 4 +++-
7 files changed, 27 insertions(+), 7 deletions(-)
diff --git a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
index 27fd6cd215290..768330d291da8 100644
--- a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
+++ b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
@@ -731,26 +731,31 @@ static int hp_init_bios_package_attribute(enum hp_wmi_data_type attr_type,
switch (attr_type) {
case HPWMI_STRING_TYPE:
ret = hp_populate_string_package_data(elements,
+ obj->package.count,
instance_id,
attr_name_kobj);
break;
case HPWMI_INTEGER_TYPE:
ret = hp_populate_integer_package_data(elements,
+ obj->package.count,
instance_id,
attr_name_kobj);
break;
case HPWMI_ENUMERATION_TYPE:
ret = hp_populate_enumeration_package_data(elements,
+ obj->package.count,
instance_id,
attr_name_kobj);
break;
case HPWMI_ORDERED_LIST_TYPE:
ret = hp_populate_ordered_list_package_data(elements,
+ obj->package.count,
instance_id,
attr_name_kobj);
break;
case HPWMI_PASSWORD_TYPE:
ret = hp_populate_password_package_data(elements,
+ obj->package.count,
instance_id,
attr_name_kobj);
break;
diff --git a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.h b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.h
index f1eec0e4ba075..416d7e7aaaae3 100644
--- a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.h
+++ b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.h
@@ -401,6 +401,7 @@ int hp_populate_string_buffer_data(u8 *buffer_ptr, u32 *buffer_size,
int hp_alloc_string_data(void);
void hp_exit_string_attributes(void);
int hp_populate_string_package_data(union acpi_object *str_obj,
+ int str_obj_count,
int instance_id,
struct kobject *attr_name_kobj);
@@ -411,6 +412,7 @@ int hp_populate_integer_buffer_data(u8 *buffer_ptr, u32 *buffer_size,
int hp_alloc_integer_data(void);
void hp_exit_integer_attributes(void);
int hp_populate_integer_package_data(union acpi_object *integer_obj,
+ int integer_obj_count,
int instance_id,
struct kobject *attr_name_kobj);
@@ -421,6 +423,7 @@ int hp_populate_enumeration_buffer_data(u8 *buffer_ptr, u32 *buffer_size,
int hp_alloc_enumeration_data(void);
void hp_exit_enumeration_attributes(void);
int hp_populate_enumeration_package_data(union acpi_object *enum_obj,
+ int enum_obj_count,
int instance_id,
struct kobject *attr_name_kobj);
@@ -432,6 +435,7 @@ int hp_populate_ordered_list_buffer_data(u8 *buffer_ptr,
int hp_alloc_ordered_list_data(void);
void hp_exit_ordered_list_attributes(void);
int hp_populate_ordered_list_package_data(union acpi_object *order_obj,
+ int order_obj_count,
int instance_id,
struct kobject *attr_name_kobj);
@@ -440,6 +444,7 @@ int hp_populate_password_buffer_data(u8 *buffer_ptr, u32 *buffer_size,
int instance_id,
struct kobject *attr_name_kobj);
int hp_populate_password_package_data(union acpi_object *password_obj,
+ int password_obj_count,
int instance_id,
struct kobject *attr_name_kobj);
int hp_alloc_password_data(void);
diff --git a/drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c b/drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c
index af4d1920d4880..de156a9f88a18 100644
--- a/drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c
+++ b/drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c
@@ -300,10 +300,12 @@ static int hp_populate_enumeration_elements_from_package(union acpi_object *enum
* Populate all properties of an instance under enumeration attribute
*
* @enum_obj: ACPI object with enumeration data
+ * @enum_obj_count: Number of elements in @enum_obj
* @instance_id: The instance to enumerate
* @attr_name_kobj: The parent kernel object
*/
int hp_populate_enumeration_package_data(union acpi_object *enum_obj,
+ int enum_obj_count,
int instance_id,
struct kobject *attr_name_kobj)
{
@@ -312,7 +314,7 @@ int hp_populate_enumeration_package_data(union acpi_object *enum_obj,
enum_data->attr_name_kobj = attr_name_kobj;
hp_populate_enumeration_elements_from_package(enum_obj,
- enum_obj->package.count,
+ enum_obj_count,
instance_id);
hp_update_attribute_permissions(enum_data->common.is_readonly,
&enumeration_current_val);
diff --git a/drivers/platform/x86/hp/hp-bioscfg/int-attributes.c b/drivers/platform/x86/hp/hp-bioscfg/int-attributes.c
index d96e160953e39..f2fd966c9ca4c 100644
--- a/drivers/platform/x86/hp/hp-bioscfg/int-attributes.c
+++ b/drivers/platform/x86/hp/hp-bioscfg/int-attributes.c
@@ -275,10 +275,12 @@ static int hp_populate_integer_elements_from_package(union acpi_object *integer_
* Populate all properties of an instance under integer attribute
*
* @integer_obj: ACPI object with integer data
+ * @integer_obj_count: Number of elements in @integer_obj
* @instance_id: The instance to enumerate
* @attr_name_kobj: The parent kernel object
*/
int hp_populate_integer_package_data(union acpi_object *integer_obj,
+ int integer_obj_count,
int instance_id,
struct kobject *attr_name_kobj)
{
@@ -286,7 +288,7 @@ int hp_populate_integer_package_data(union acpi_object *integer_obj,
integer_data->attr_name_kobj = attr_name_kobj;
hp_populate_integer_elements_from_package(integer_obj,
- integer_obj->package.count,
+ integer_obj_count,
instance_id);
hp_update_attribute_permissions(integer_data->common.is_readonly,
&integer_current_val);
diff --git a/drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c b/drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c
index f09489a085c86..cc5bebe73a93b 100644
--- a/drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c
+++ b/drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c
@@ -298,10 +298,12 @@ static int hp_populate_ordered_list_elements_from_package(union acpi_object *ord
* Populate all properties of an instance under ordered_list attribute
*
* @order_obj: ACPI object with ordered_list data
+ * @order_obj_count: Number of elements in @order_obj
* @instance_id: The instance to enumerate
* @attr_name_kobj: The parent kernel object
*/
-int hp_populate_ordered_list_package_data(union acpi_object *order_obj, int instance_id,
+int hp_populate_ordered_list_package_data(union acpi_object *order_obj, int order_obj_count,
+ int instance_id,
struct kobject *attr_name_kobj)
{
struct ordered_list_data *ordered_list_data = &bioscfg_drv.ordered_list_data[instance_id];
@@ -309,7 +311,7 @@ int hp_populate_ordered_list_package_data(union acpi_object *order_obj, int inst
ordered_list_data->attr_name_kobj = attr_name_kobj;
hp_populate_ordered_list_elements_from_package(order_obj,
- order_obj->package.count,
+ order_obj_count,
instance_id);
hp_update_attribute_permissions(ordered_list_data->common.is_readonly,
&ordered_list_current_val);
diff --git a/drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c b/drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c
index 4d79eb8056a5d..ed5e2080f22bd 100644
--- a/drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c
+++ b/drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c
@@ -385,10 +385,12 @@ static int hp_populate_password_elements_from_package(union acpi_object *passwor
* Populate all properties for an instance under password attribute
*
* @password_obj: ACPI object with password data
+ * @password_obj_count: Number of elements in @password_obj
* @instance_id: The instance to enumerate
* @attr_name_kobj: The parent kernel object
*/
-int hp_populate_password_package_data(union acpi_object *password_obj, int instance_id,
+int hp_populate_password_package_data(union acpi_object *password_obj, int password_obj_count,
+ int instance_id,
struct kobject *attr_name_kobj)
{
struct password_data *password_data = &bioscfg_drv.password_data[instance_id];
@@ -396,7 +398,7 @@ int hp_populate_password_package_data(union acpi_object *password_obj, int insta
password_data->attr_name_kobj = attr_name_kobj;
hp_populate_password_elements_from_package(password_obj,
- password_obj->package.count,
+ password_obj_count,
instance_id);
hp_friendly_user_name_update(password_data->common.path,
diff --git a/drivers/platform/x86/hp/hp-bioscfg/string-attributes.c b/drivers/platform/x86/hp/hp-bioscfg/string-attributes.c
index fe5a9a3a4ef17..f98c32dacbc74 100644
--- a/drivers/platform/x86/hp/hp-bioscfg/string-attributes.c
+++ b/drivers/platform/x86/hp/hp-bioscfg/string-attributes.c
@@ -263,10 +263,12 @@ static int hp_populate_string_elements_from_package(union acpi_object *string_ob
* Populate all properties of an instance under string attribute
*
* @string_obj: ACPI object with string data
+ * @string_obj_count: Number of elements in @string_obj
* @instance_id: The instance to enumerate
* @attr_name_kobj: The parent kernel object
*/
int hp_populate_string_package_data(union acpi_object *string_obj,
+ int string_obj_count,
int instance_id,
struct kobject *attr_name_kobj)
{
@@ -275,7 +277,7 @@ int hp_populate_string_package_data(union acpi_object *string_obj,
string_data->attr_name_kobj = attr_name_kobj;
hp_populate_string_elements_from_package(string_obj,
- string_obj->package.count,
+ string_obj_count,
instance_id);
hp_update_attribute_permissions(string_data->common.is_readonly,
--
2.55.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v5 3/4] platform/x86: hp-bioscfg: accept reduced ACPI packages from older HP BIOS
2026-07-09 16:58 [PATCH v5 0/4] platform/x86: hp-bioscfg: fix ACPI package handling on HP EliteBook 840 G2 Muhammad Bilal
2026-07-09 16:58 ` [PATCH v5 1/4] platform/x86: hp-bioscfg: pass validated element count to package parsers Muhammad Bilal
2026-07-09 16:58 ` [PATCH v5 2/4] platform/x86: hp-bioscfg: bound ordered-list parsing by the package count Muhammad Bilal
@ 2026-07-09 16:58 ` Muhammad Bilal
2026-07-09 16:58 ` [PATCH v5 4/4] platform/x86: hp-bioscfg: warn on element type mismatch instead of failing Muhammad Bilal
2026-07-10 10:21 ` [PATCH v5 0/4] platform/x86: hp-bioscfg: fix ACPI package handling on HP EliteBook 840 G2 Ilpo Järvinen
4 siblings, 0 replies; 6+ messages in thread
From: Muhammad Bilal @ 2026-07-09 16:58 UTC (permalink / raw)
To: Hans de Goede, Ilpo Järvinen, Jorge Lopez,
Thomas Weißschuh, platform-driver-x86, linux-kernel
Cc: stable, Mario Limonciello, Armin Wolf, Muhammad Bilal
hp_init_bios_package_attribute() hard-fails when a WMI ACPI package
contains fewer elements than the type-specific expected count (e.g. 11
elements instead of 13 for INTEGER or ENUMERATION attributes). This
causes the entire hp_bioscfg driver to skip attribute enumeration on
older HP hardware whose BIOS returns shortened packages when optional
fields like prerequisites or possible values are absent.
Observed on HP EliteBook 840 G2 (BIOS M71 Ver. 01.31):
hp_bioscfg: ACPI-package does not have enough elements: 11 < 13
The element layout has two tiers:
- Elements 0-9 (SECURITY_LEVEL+1 = 10): common to all attribute types
- Elements 10-N: type-specific (bounds, values, encodings, ...)
The per-type populate functions (hp_populate_*_elements_from_package)
already handle sparse packages correctly via their own elem < count
loop guards and inner-loop bounds checks. The only unsafe case is when
we lack even the common elements needed to register the attribute.
Fix by introducing COMMON_ELEM_CNT to mark the hard minimum (10), and
splitting the check into two tiers:
- Fewer than COMMON_ELEM_CNT elements: hard fail, can't proceed.
- Fewer than expected type-specific elements: warn, but let the
populate function parse what is available.
Fixes: a34fc329b189 ("platform/x86: hp-bioscfg: bioscfg")
Cc: stable@vger.kernel.org
Signed-off-by: Muhammad Bilal <meatuni001@gmail.com>
---
drivers/platform/x86/hp/hp-bioscfg/bioscfg.c | 11 ++++++++---
drivers/platform/x86/hp/hp-bioscfg/bioscfg.h | 3 +++
2 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
index 768330d291da8..78019644ec358 100644
--- a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
+++ b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
@@ -661,12 +661,17 @@ static int hp_init_bios_package_attribute(enum hp_wmi_data_type attr_type,
int ret = 0;
/* Take action appropriate to each ACPI TYPE */
- if (obj->package.count < min_elements) {
- pr_err("ACPI-package does not have enough elements: %d < %d\n",
- obj->package.count, min_elements);
+ if (obj->package.count < COMMON_ELEM_CNT) {
+ pr_err("ACPI-package is missing common elements: %d < %d\n",
+ obj->package.count, COMMON_ELEM_CNT);
goto pack_attr_exit;
}
+ if (obj->package.count < min_elements) {
+ pr_warn("ACPI-package has fewer elements than expected: %d < %d, parsing available elements\n",
+ obj->package.count, min_elements);
+ }
+
elements = obj->package.elements;
/* sanity checking */
diff --git a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.h b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.h
index 416d7e7aaaae3..ac57d6eab4c35 100644
--- a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.h
+++ b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.h
@@ -279,6 +279,9 @@ enum hp_wmi_data_elements {
PSWD_ENCODINGS = 13,
PSWD_IS_SET = 14,
PSWD_ELEM_CNT = 15,
+
+ /* Minimum elements shared by all attribute types (NAME..SECURITY_LEVEL) */
+ COMMON_ELEM_CNT = SECURITY_LEVEL + 1,
};
#define GET_INSTANCE_ID(type) \
--
2.55.0
^ permalink raw reply related [flat|nested] 6+ messages in thread