From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BE59CC001DD for ; Thu, 13 Jul 2023 14:23:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229523AbjGMOXZ (ORCPT ); Thu, 13 Jul 2023 10:23:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39358 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229472AbjGMOXY (ORCPT ); Thu, 13 Jul 2023 10:23:24 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9E18526AF; Thu, 13 Jul 2023 07:23:23 -0700 (PDT) Received: from dggpeml500012.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4R1xd94V56zVjbZ; Thu, 13 Jul 2023 22:22:05 +0800 (CST) Received: from [10.67.110.218] (10.67.110.218) by dggpeml500012.china.huawei.com (7.185.36.15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Thu, 13 Jul 2023 22:23:20 +0800 Message-ID: Date: Thu, 13 Jul 2023 22:23:20 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.6.0 Subject: Re: [PATCH] traing: Fix memory leak of iter->temp when reading trace_pipe Content-Language: en-US To: , CC: , References: <20230713141435.1133021-1-zhengyejian1@huawei.com> From: Zheng Yejian In-Reply-To: <20230713141435.1133021-1-zhengyejian1@huawei.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.67.110.218] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpeml500012.china.huawei.com (7.185.36.15) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org On 2023/7/13 22:14, Zheng Yejian wrote: > kmemleak reports: > unreferenced object 0xffff88814d14e200 (size 256): > comm "cat", pid 336, jiffies 4294871818 (age 779.490s) > hex dump (first 32 bytes): > 04 00 01 03 00 00 00 00 08 00 00 00 00 00 00 00 ................ > 0c d8 c8 9b ff ff ff ff 04 5a ca 9b ff ff ff ff .........Z...... > backtrace: > [] __kmalloc+0x4f/0x140 > [] trace_find_next_entry+0xbb/0x1d0 > [] trace_print_lat_context+0xaf/0x4e0 > [] print_trace_line+0x3e0/0x950 > [] tracing_read_pipe+0x2d9/0x5a0 > [] vfs_read+0x143/0x520 > [] ksys_read+0xbd/0x160 > [] do_syscall_64+0x3f/0x90 > [] entry_SYSCALL_64_after_hwframe+0x6e/0xd8 > > when reading file 'trace_pipe', 'iter->temp' is allocated or relocated > in trace_find_next_entry() but not freed before 'trace_pipe' is closed. > > To fix it, free 'iter->temp' in tracing_release_pipe(). > Sorry, forget the Fixes tag:( Is following Fixes right? Fixes: ff895103a84a ("tracing: Save off entry when peeking at next entry") > Signed-off-by: Zheng Yejian > --- > kernel/trace/trace.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index 4529e264cb86..94cfaa884578 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -6764,6 +6764,7 @@ static int tracing_release_pipe(struct inode *inode, struct file *file) > > free_cpumask_var(iter->started); > kfree(iter->fmt); > + kfree(iter->temp); > mutex_destroy(&iter->mutex); > kfree(iter); >