From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753880Ab2JOQmL (ORCPT ); Mon, 15 Oct 2012 12:42:11 -0400 Received: from g1t0027.austin.hp.com ([15.216.28.34]:15674 "EHLO g1t0027.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752024Ab2JOQmJ (ORCPT ); Mon, 15 Oct 2012 12:42:09 -0400 From: Toshi Kani To: linux-acpi@vger.kernel.org, lenb@kernel.org Cc: linux-kernel@vger.kernel.org, rjw@sisk.pl, isimatu.yasuaki@jp.fujitsu.com, liuj97@gmail.com, Toshi Kani Subject: [PATCH 1/2] ACPI: Fix stale pointer access to flags.lockable Date: Mon, 15 Oct 2012 10:34:29 -0600 Message-Id: <1350318870-5700-1-git-send-email-toshi.kani@hp.com> X-Mailer: git-send-email 1.7.11.7 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org During hot-remove, acpi_bus_hot_remove_device() calls ACPI _LCK method when device->flags.lockable is set. However, this device pointer is stale since the target acpi_device object has been already kfree'd by acpi_bus_trim(). The flags.lockable indicates whether or not this ACPI object implements _LCK method. Fix the stable pointer access by replacing it with acpi_get_handle() to check if _LCK is implemented. Signed-off-by: Toshi Kani --- drivers/acpi/scan.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 1fcb867..ed87f43 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -97,6 +97,7 @@ void acpi_bus_hot_remove_device(void *context) struct acpi_eject_event *ej_event = (struct acpi_eject_event *) context; struct acpi_device *device; acpi_handle handle = ej_event->handle; + acpi_handle temp; struct acpi_object_list arg_list; union acpi_object arg; acpi_status status = AE_OK; @@ -117,13 +118,16 @@ void acpi_bus_hot_remove_device(void *context) goto err_out; } + /* device has been freed */ + device = NULL; + /* power off device */ status = acpi_evaluate_object(handle, "_PS3", NULL, NULL); if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) printk(KERN_WARNING PREFIX "Power-off device failed\n"); - if (device->flags.lockable) { + if (ACPI_SUCCESS(acpi_get_handle(handle, "_LCK", &temp))) { arg_list.count = 1; arg_list.pointer = &arg; arg.type = ACPI_TYPE_INTEGER; -- 1.7.11.7