From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753578AbZFOCzU (ORCPT ); Sun, 14 Jun 2009 22:55:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752082AbZFOCzJ (ORCPT ); Sun, 14 Jun 2009 22:55:09 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:56929 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751294AbZFOCzI (ORCPT ); Sun, 14 Jun 2009 22:55:08 -0400 Message-ID: <4A35B86A.7070608@cn.fujitsu.com> Date: Mon, 15 Jun 2009 10:56:42 +0800 From: Li Zefan User-Agent: Thunderbird 2.0.0.9 (X11/20071115) MIME-Version: 1.0 To: Ingo Molnar CC: Steven Rostedt , Frederic Weisbecker , LKML Subject: [PATCH 1/4] tracing: fix a typo in tracing_cpumask_write() References: <4A35B84B.40904@cn.fujitsu.com> In-Reply-To: <4A35B84B.40904@cn.fujitsu.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It's tracing_cpumask_new that should be kfree()ed. This causes tracing_cpumask to be freed due to the typo: # echo z > tracing_cpumask bash: echo: write error: Invalid argument And subsequent reads/writes to tracing_cpuamsk will access this already-freed tracing_cpumask, thus may lead to crash. [ Impact: fix leak and crash when writing invalid val to tracing_cpumask ] Signed-off-by: Li Zefan --- kernel/trace/trace.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8acd9b8..7355a38 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2191,11 +2191,12 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf, if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL)) return -ENOMEM; - mutex_lock(&tracing_cpumask_update_lock); err = cpumask_parse_user(ubuf, count, tracing_cpumask_new); if (err) goto err_unlock; + mutex_lock(&tracing_cpumask_update_lock); + local_irq_disable(); __raw_spin_lock(&ftrace_max_lock); for_each_tracing_cpu(cpu) { @@ -2223,8 +2224,7 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf, return count; err_unlock: - mutex_unlock(&tracing_cpumask_update_lock); - free_cpumask_var(tracing_cpumask); + free_cpumask_var(tracing_cpumask_new); return err; } -- 1.5.4.rc3