From: Muhammad Bilal <meatuni001@gmail.com>
To: hdegoede@redhat.com, ilpo.jarvinen@linux.intel.com,
jorge.lopez2@hp.com, Thomas.Weissschuh@linutronix.de,
platform-driver-x86@vger.kernel.org,
linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org, Mario Limonciello <superm1@kernel.org>,
Armin Wolf <W_Armin@gmx.de>,
Muhammad Bilal <meatuni001@gmail.com>
Subject: [PATCH v2 1/3] platform/x86: hp-bioscfg: pass validated element count to package parsers
Date: Sat, 4 Jul 2026 21:07:57 +0500 [thread overview]
Message-ID: <20260704160759.236249-2-meatuni001@gmail.com> (raw)
In-Reply-To: <20260704160759.236249-1-meatuni001@gmail.com>
hp_init_bios_package_attribute() validates obj->package.count against
min_elements and then hands off elements = obj->package.elements to
one of the five per-type hp_populate_*_package_data() wrappers
(string, integer, enumeration, ordered list, password). None of these
wrappers receive that validated count. Instead each one re-derives it
locally:
hp_populate_integer_elements_from_package(integer_obj,
integer_obj->package.count,
instance_id);
integer_obj here is elements, i.e. a pointer to elements[0] (the NAME
field, always ACPI_TYPE_STRING). Reading ->package.count off a string
object aliases ->string.length in the underlying union acpi_object, so
the "count" passed down is not the real package size at all.
For string, integer, enumeration and password attributes,
hp_populate_*_elements_from_package() bounds its iteration using the
corresponding per-type ELEM_CNT constant (STR_ELEM_CNT,
INT_ELEM_CNT, ENUM_ELEM_CNT and PSWD_ELEM_CNT). This relies on
hp_init_bios_package_attribute() rejecting packages with fewer than
ELEM_CNT elements before invoking the parsers.
Relaxing that check would allow shorter packages to reach these
functions, making the fixed loop bounds unsafe.
hp_populate_ordered_list_elements_from_package() doesn't even use the
count for its main loop bound - it iterates unconditionally up to
ORD_ELEM_CNT:
for (elem = 1, eloc = 1; eloc < ORD_ELEM_CNT; elem++, eloc++)
which relies entirely on the same coincidence.
This is only safe as long as every caller is guaranteed to hand these
functions a package with at least ELEM_CNT real elements. A following
change relaxes that guarantee to allow shorter packages through, which
would turn this into a real out-of-bounds heap read of the
elements[] array once the real count drops below the fixed ELEM_CNT
loop bound.
Fix this at the source: thread the real, already-validated
obj->package.count down through each *_package_data() wrapper instead
of letting the per-type code guess at it, and use it to also bound
hp_populate_ordered_list_elements_from_package()'s main loop. This is a
no-op for any package that already meets the existing ELEM_CNT
minimums, and is a prerequisite for safely accepting shorter packages.
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 | 5 +++++
drivers/platform/x86/hp/hp-bioscfg/bioscfg.h | 5 +++++
drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c | 3 ++-
drivers/platform/x86/hp/hp-bioscfg/int-attributes.c | 3 ++-
drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c | 7 ++++---
drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c | 5 +++--
drivers/platform/x86/hp/hp-bioscfg/string-attributes.c | 3 ++-
7 files changed, 23 insertions(+), 8 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..3aa2c440e0528 100644
--- a/drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c
+++ b/drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c
@@ -304,6 +304,7 @@ static int hp_populate_enumeration_elements_from_package(union acpi_object *enum
* @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 +313,7 @@ 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..107e4cf1efb8a 100644
--- a/drivers/platform/x86/hp/hp-bioscfg/int-attributes.c
+++ b/drivers/platform/x86/hp/hp-bioscfg/int-attributes.c
@@ -279,6 +279,7 @@ static int hp_populate_integer_elements_from_package(union acpi_object *integer_
* @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 +287,7 @@ 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..a50d074125268 100644
--- a/drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c
+++ b/drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c
@@ -145,7 +145,7 @@ static int hp_populate_ordered_list_elements_from_package(union acpi_object *ord
if (!order_obj)
return -EINVAL;
- for (elem = 1, eloc = 1; eloc < ORD_ELEM_CNT; elem++, eloc++) {
+ for (elem = 1, eloc = 1; eloc < ORD_ELEM_CNT && elem < order_obj_count; elem++, eloc++) {
switch (order_obj[elem].type) {
case ACPI_TYPE_STRING:
@@ -301,7 +301,8 @@ static int hp_populate_ordered_list_elements_from_package(union acpi_object *ord
* @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 +310,7 @@ 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..89316d90454d2 100644
--- a/drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c
+++ b/drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c
@@ -388,7 +388,8 @@ static int hp_populate_password_elements_from_package(union acpi_object *passwor
* @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 +397,7 @@ 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..da5e81f1d188f 100644
--- a/drivers/platform/x86/hp/hp-bioscfg/string-attributes.c
+++ b/drivers/platform/x86/hp/hp-bioscfg/string-attributes.c
@@ -267,6 +267,7 @@ static int hp_populate_string_elements_from_package(union acpi_object *string_ob
* @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 +276,7 @@ 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
next prev parent reply other threads:[~2026-07-04 16:08 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-04 16:07 [PATCH v2 0/3] hp-bioscfg: fix attribute enumeration on older HP BIOS Muhammad Bilal
2026-07-04 16:07 ` Muhammad Bilal [this message]
2026-07-06 17:56 ` [PATCH v2 1/3] platform/x86: hp-bioscfg: pass validated element count to package parsers Ilpo Järvinen
2026-07-07 20:26 ` Muhammad Bilal
2026-07-04 16:07 ` [PATCH v2 2/3] platform/x86: hp-bioscfg: accept reduced ACPI packages from older HP BIOS Muhammad Bilal
2026-07-04 16:07 ` [PATCH v2 3/3] platform/x86: hp-bioscfg: warn on element type mismatch instead of failing Muhammad Bilal
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