[PATCH] acpi: fix null pointer deference of hardware_id string

[Lin Ming <ming.m.lin@intel.com>]

From: Lin Ming <ming.m.lin@intel.com>
Date: Thu, 13 Aug 2009 11:04:47 +0800
Subject: [PATCH] acpi: fix null pointer deference of hardware_id string

This regression was caused by commit ed44482
"ACPICA: Major update for acpi_get_object_info external interface"

Don't need to set hardware_id string \0 terminated here,
acpi_get_object_info already handles it.

Tested-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
---
 drivers/char/agp/hp-agp.c         |    6 ++++--
 drivers/pci/hotplug/acpiphp_ibm.c |    1 -
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/char/agp/hp-agp.c b/drivers/char/agp/hp-agp.c
index 7bead4c..d83c4a8 100644
--- a/drivers/char/agp/hp-agp.c
+++ b/drivers/char/agp/hp-agp.c
@@ -492,8 +492,10 @@ zx1_gart_probe (acpi_handle obj, u32 depth, void *context, void **ret)
 		status = acpi_get_object_info(handle, &info);
 		if (ACPI_SUCCESS(status)) {
 			/* TBD check _CID also */
-			info->hardware_id.string[sizeof(info->hardware_id.length)-1] = '\0';
-			match = (strcmp(info->hardware_id.string, "HWP0001") == 0);
+			if (info->valid & ACPI_VALID_HID)
+				match = !strcmp(info->hardware_id.string, "HWP0001");
+			else
+				match = 0;
 			kfree(info);
 			if (match) {
 				status = hp_acpi_csr_space(handle, &sba_hpa, &length);
diff --git a/drivers/pci/hotplug/acpiphp_ibm.c b/drivers/pci/hotplug/acpiphp_ibm.c
index a9d926b..e7be66d 100644
--- a/drivers/pci/hotplug/acpiphp_ibm.c
+++ b/drivers/pci/hotplug/acpiphp_ibm.c
@@ -406,7 +406,6 @@ static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
 			__func__, status);
 		return retval;
 	}
-	info->hardware_id.string[sizeof(info->hardware_id.length) - 1] = '\0';
 
 	if (info->current_status && (info->valid & ACPI_VALID_HID) &&
 			(!strcmp(info->hardware_id.string, IBM_HARDWARE_ID1) ||