Unverified Commit 25150715 authored by Mario Limonciello's avatar Mario Limonciello Committed by Ilpo Järvinen
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platform/x86: hp-bioscfg: Fix kernel panic in GET_INSTANCE_ID macro 



The GET_INSTANCE_ID macro that caused a kernel panic when accessing sysfs
attributes:

1. Off-by-one error: The loop condition used '<=' instead of '<',
   causing access beyond array bounds. Since array indices are 0-based
   and go from 0 to instances_count-1, the loop should use '<'.

2. Missing NULL check: The code dereferenced attr_name_kobj->name
   without checking if attr_name_kobj was NULL, causing a null pointer
   dereference in min_length_show() and other attribute show functions.

The panic occurred when fwupd tried to read BIOS configuration attributes:

  Oops: general protection fault [#1] SMP KASAN NOPTI
  KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
  RIP: 0010:min_length_show+0xcf/0x1d0 [hp_bioscfg]

Add a NULL check for attr_name_kobj before dereferencing and corrects
the loop boundary to match the pattern used elsewhere in the driver.

Cc: stable@vger.kernel.org
Fixes: 5f94f181 ("platform/x86: hp-bioscfg: bioscfg-h")
Signed-off-by: default avatarMario Limonciello <mario.limonciello@amd.com>
Link: https://patch.msgid.link/20260115203725.828434-3-mario.limonciello@amd.com


Reviewed-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
parent fdee1b09

drivers/platform/x86/hp/hp-bioscfg/bioscfg.h

+4 −2
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 


#include <linux/wmi.h>

#include <linux/types.h>

#include <linux/string.h>

#include <linux/device.h>

#include <linux/module.h>

#include <linux/kernel.h>
@@ -285,8 +286,9 @@ enum hp_wmi_data_elements { 
	{								\

		int i;							\

									\

		for (i = 0; i <= bioscfg_drv.type##_instances_count; i++) { \

			if (!strcmp(kobj->name, bioscfg_drv.type##_data[i].attr_name_kobj->name)) \

		for (i = 0; i < bioscfg_drv.type##_instances_count; i++) { \

			if (bioscfg_drv.type##_data[i].attr_name_kobj &&	\

			    !strcmp(kobj->name, bioscfg_drv.type##_data[i].attr_name_kobj->name)) \

				return i;				\

		}							\

		return -EIO;						\