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 40B70C4332F for ; Fri, 21 Oct 2022 03:13:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229542AbiJUDNG (ORCPT ); Thu, 20 Oct 2022 23:13:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46620 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230041AbiJUDMr (ORCPT ); Thu, 20 Oct 2022 23:12:47 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F1B9813C1FA for ; Thu, 20 Oct 2022 20:12:44 -0700 (PDT) Received: from dggpeml500022.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4MtqCc2vKTzmVDJ; Fri, 21 Oct 2022 11:07:56 +0800 (CST) Received: from dggpeml500016.china.huawei.com (7.185.36.70) by dggpeml500022.china.huawei.com (7.185.36.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Fri, 21 Oct 2022 11:12:40 +0800 Received: from [10.174.176.102] (10.174.176.102) by dggpeml500016.china.huawei.com (7.185.36.70) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Fri, 21 Oct 2022 11:12:40 +0800 Message-ID: <1fcc1cf2-6990-af2a-958d-c2d25c4bc8cc@huawei.com> Date: Fri, 21 Oct 2022 11:12:40 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.3.2 Subject: Re: [PATCH v2] misc/fsck.c: Processes may kill other processes. From: zhanchengbin To: Theodore Ts'o CC: , Lukas Czerner , , linfeilong References: <2c8f3b3a-b6d1-9b8b-27c7-2df51236fe8c@huawei.com> In-Reply-To: <2c8f3b3a-b6d1-9b8b-27c7-2df51236fe8c@huawei.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.176.102] X-ClientProxiedBy: dggpeml500024.china.huawei.com (7.185.36.10) To dggpeml500016.china.huawei.com (7.185.36.70) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org ping... On 2022/10/10 16:56, zhanchengbin wrote: > I find a error in misc/fsck.c, if run the fsck -N command, processes > don't execute, just show what would be done. However, the pid whose > value is -1 is added to the instance_list list in the execute > function,if the kill_all function is called later, kill(-1, signum) > is executed, Signals are sent to all processes except the number one > process and itself. Other processes will be killed if they use the > default signal processing function. > > Signed-off-by: zhanchengbin > Signed-off-by: Lukas Czerner > --- > V1->V2: >   Anything <= 0 is a bug and can have unexpected consequences if > we actually call the kill(). So change inst->pid==-1 to inst->pid<=0. > >  misc/fsck.c | 2 ++ >  1 file changed, 2 insertions(+) > > diff --git a/misc/fsck.c b/misc/fsck.c > index 4efe10ec..c56d1b00 100644 > --- a/misc/fsck.c > +++ b/misc/fsck.c > @@ -546,6 +546,8 @@ static int kill_all(int signum) >      for (inst = instance_list; inst; inst = inst->next) { >          if (inst->flags & FLAG_DONE) >              continue; > +        if (inst->pid <= 0) > +            continue; >          kill(inst->pid, signum); >          n++; >      }