From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422942AbaDKQJd (ORCPT ); Fri, 11 Apr 2014 12:09:33 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:56306 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758967AbaDKQH2 (ORCPT ); Fri, 11 Apr 2014 12:07:28 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Fu , "Rafael J. Wysocki" , Mark Brown Subject: [PATCH 3.10 06/41] cpuidle: Check the result of cpuidle_get_driver() against NULL Date: Fri, 11 Apr 2014 09:09:37 -0700 Message-Id: <20140411160933.313940597@linuxfoundation.org> X-Mailer: git-send-email 1.9.0 In-Reply-To: <20140411160932.865173041@linuxfoundation.org> References: <20140411160932.865173041@linuxfoundation.org> User-Agent: quilt/0.60-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Daniel Fu commit 3b9c10e98021e1f92e6f8c7ce1778b86ba68db10 upstream. If the current CPU has no cpuidle driver, drv will be NULL in cpuidle_driver_ref(). Check if that is the case before trying to bump up the driver's refcount to prevent the kernel from crashing. [rjw: Subject and changelog] Signed-off-by: Daniel Fu Signed-off-by: Rafael J. Wysocki Cc: Mark Brown Signed-off-by: Greg Kroah-Hartman --- drivers/cpuidle/driver.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/cpuidle/driver.c +++ b/drivers/cpuidle/driver.c @@ -251,7 +251,8 @@ struct cpuidle_driver *cpuidle_driver_re spin_lock(&cpuidle_driver_lock); drv = cpuidle_get_driver(); - drv->refcnt++; + if (drv) + drv->refcnt++; spin_unlock(&cpuidle_driver_lock); return drv;