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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3B41FC433FE for ; Thu, 18 Nov 2021 14:15:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 20AF061181 for ; Thu, 18 Nov 2021 14:15:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232822AbhKROSp (ORCPT ); Thu, 18 Nov 2021 09:18:45 -0500 Received: from www262.sakura.ne.jp ([202.181.97.72]:65067 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232958AbhKROSU (ORCPT ); Thu, 18 Nov 2021 09:18:20 -0500 Received: from fsav314.sakura.ne.jp (fsav314.sakura.ne.jp [153.120.85.145]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id 1AIEFAIN035187; Thu, 18 Nov 2021 23:15:10 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav314.sakura.ne.jp (F-Secure/fsigk_smtp/550/fsav314.sakura.ne.jp); Thu, 18 Nov 2021 23:15:10 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/fsav314.sakura.ne.jp) Received: from [192.168.1.9] (M106072142033.v4.enabler.ne.jp [106.72.142.33]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id 1AIEF9YL035183 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NO); Thu, 18 Nov 2021 23:15:10 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Message-ID: Date: Thu, 18 Nov 2021 23:15:07 +0900 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.3.1 Subject: Re: [PATCH] loop: mask loop_control_ioctl parameter only as minor Content-Language: en-US To: wangyangbo , axboe@kernel.dk Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org References: <20211118023640.32559-1-yangbonis@icloud.com> From: Tetsuo Handa In-Reply-To: <20211118023640.32559-1-yangbonis@icloud.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 2021/11/18 11:36, wangyangbo wrote: > @@ -2170,11 +2170,11 @@ static long loop_control_ioctl(struct file *file, unsigned int cmd, > { > switch (cmd) { > case LOOP_CTL_ADD: > - return loop_add(parm); > + return loop_add(MINOR(parm)); Better to return -EINVAL or something if out of minor range? > case LOOP_CTL_REMOVE: > - return loop_control_remove(parm); > + return loop_control_remove(MINOR(parm)); This is bad, for this change makes if (idx < 0) { pr_warn("deleting an unspecified loop device is not supported.\n"); return -EINVAL; } dead code by masking the argument to 0-1048575 range. > case LOOP_CTL_GET_FREE: > - return loop_control_get_free(parm); > + return loop_control_get_free(MINOR(parm)); This is pointless, for the passed argument is not used. By the way, didn't someone already propose removal of this argument? > default: > return -ENOSYS; > } >