From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932818Ab2GYDma (ORCPT ); Tue, 24 Jul 2012 23:42:30 -0400 Received: from mail-qc0-f174.google.com ([209.85.216.174]:46154 "EHLO mail-qc0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932714Ab2GYDm0 (ORCPT ); Tue, 24 Jul 2012 23:42:26 -0400 From: Len Brown To: linux-acpi@vger.kernel.org, linux-pm@lists.linux-foundation.org Cc: linux-kernel@vger.kernel.org, "Srivatsa S. Bhat" , Andrew Morton , Len Brown Subject: [PATCH 13/52] cpuidle: add checks to avoid NULL pointer dereference Date: Tue, 24 Jul 2012 23:41:09 -0400 Message-Id: <1b0a0e9a15b976d91f3b5ae619c6a8964c2818eb.1343187617.git.len.brown@intel.com> X-Mailer: git-send-email 1.7.12.rc0 In-Reply-To: <1343187708-19532-1-git-send-email-lenb@kernel.org> References: <1343187708-19532-1-git-send-email-lenb@kernel.org> In-Reply-To: <6af1c4fc5227af65092ebc848989693562bfa3e8.1343187617.git.len.brown@intel.com> References: <6af1c4fc5227af65092ebc848989693562bfa3e8.1343187617.git.len.brown@intel.com> Reply-To: Len Brown Organization: Intel Open Source Technology Center Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Srivatsa S. Bhat" The existing check for dev == NULL in __cpuidle_register_device() is rendered useless because dev is dereferenced before the check itself. Moreover, correctly speaking, it is the job of the callers of this function, i.e., cpuidle_register_device() & cpuidle_enable_device() (which also happen to be exported functions) to ensure that __cpuidle_register_device() is called with a non-NULL dev. So add the necessary dev == NULL checks in the two callers and remove the (useless) check from __cpuidle_register_device(). Signed-off-by: Srivatsa S. Bhat Acked-by: Daniel Lezcano Signed-off-by: Andrew Morton Signed-off-by: Len Brown --- drivers/cpuidle/cpuidle.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 588b44a..8ffef26 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -285,6 +285,9 @@ int cpuidle_enable_device(struct cpuidle_device *dev) int ret, i; struct cpuidle_driver *drv = cpuidle_get_driver(); + if (!dev) + return -EINVAL; + if (dev->enabled) return 0; if (!drv || !cpuidle_curr_governor) @@ -369,8 +372,6 @@ static int __cpuidle_register_device(struct cpuidle_device *dev) struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu); struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver(); - if (!dev) - return -EINVAL; if (!try_module_get(cpuidle_driver->owner)) return -EINVAL; @@ -395,6 +396,9 @@ int cpuidle_register_device(struct cpuidle_device *dev) { int ret; + if (!dev) + return -EINVAL; + mutex_lock(&cpuidle_lock); if ((ret = __cpuidle_register_device(dev))) { -- 1.7.12.rc0