From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jan Beulich , Konrad Rzeszutek Wilk , "Rafael J. Wysocki" , Daniel Kiper Subject: [PATCH 3.4 014/134] intel_idle: Check cpu_idle_get_driver() for NULL before dereferencing it. Date: Wed, 9 Apr 2014 20:22:10 -0700 Message-Id: <20140410032301.630515702@linuxfoundation.org> In-Reply-To: <20140410032259.587501440@linuxfoundation.org> References: <20140410032259.587501440@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Konrad Rzeszutek Wilk commit 3735d524da64b70b41c764359da36f88aded3610 upstream. If the machine is booted without any cpu_idle driver set (b/c disable_cpuidle() has been called) we should follow other users of cpu_idle API and check the return value for NULL before using it. Reported-and-tested-by: Mark van Dijk Suggested-by: Jan Beulich Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Rafael J. Wysocki Cc: Daniel Kiper Signed-off-by: Greg Kroah-Hartman --- drivers/idle/intel_idle.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -594,8 +594,9 @@ static int __init intel_idle_init(void) intel_idle_cpuidle_driver_init(); retval = cpuidle_register_driver(&intel_idle_driver); if (retval) { + struct cpuidle_driver *drv = cpuidle_get_driver(); printk(KERN_DEBUG PREFIX "intel_idle yielding to %s", - cpuidle_get_driver()->name); + drv ? drv->name : "none"); return retval; }