From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757016Ab2LNW06 (ORCPT ); Fri, 14 Dec 2012 17:26:58 -0500 Received: from mail.kernel.org ([198.145.19.201]:38111 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756960Ab2LNW04 (ORCPT ); Fri, 14 Dec 2012 17:26:56 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, "Rafael J. Wysocki" Subject: [ 16/22] ACPI / PNP: Do not crash due to stale pointer use during system resume Date: Fri, 14 Dec 2012 14:26:01 -0800 Message-Id: <20121214222253.555232738@linuxfoundation.org> X-Mailer: git-send-email 1.8.1.rc1.5.g7e0651a In-Reply-To: <20121214222249.889051473@linuxfoundation.org> References: <20121214222249.889051473@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Rafael J. Wysocki" commit a6b5e88c0e42093b9057856f35770966c8c591e3 upstream. During resume from system suspend the 'data' field of struct pnp_dev in pnpacpi_set_resources() may be a stale pointer, due to removal of the associated ACPI device node object in the previous suspend-resume cycle. This happens, for example, if a dockable machine is booted in the docking station and then suspended and resumed and suspended again. If that happens, pnpacpi_build_resource_template() called from pnpacpi_set_resources() attempts to use that pointer and crashes. However, pnpacpi_set_resources() actually checks the device's ACPI handle, attempts to find the ACPI device node object attached to it and returns an error code if that fails, so in fact it knows what the correct value of dev->data should be. Use this observation to update dev->data with the correct value if necessary and dump a call trace if that's the case (once). We still need to fix the root cause of this issue, but preventing systems from crashing because of it is an improvement too. Reported-and-tested-by: Zdenek Kabelac References: https://bugzilla.kernel.org/show_bug.cgi?id=51071 Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman --- drivers/pnp/pnpacpi/core.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/pnp/pnpacpi/core.c +++ b/drivers/pnp/pnpacpi/core.c @@ -94,6 +94,9 @@ static int pnpacpi_set_resources(struct return -ENODEV; } + if (WARN_ON_ONCE(acpi_dev != dev->data)) + dev->data = acpi_dev; + ret = pnpacpi_build_resource_template(dev, &buffer); if (ret) return ret;