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 AF91FC433EF for ; Thu, 18 Nov 2021 02:42:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 90D4F61AEC for ; Thu, 18 Nov 2021 02:42:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242040AbhKRCpr (ORCPT ); Wed, 17 Nov 2021 21:45:47 -0500 Received: from pv50p00im-hyfv10021501.me.com ([17.58.6.48]:37330 "EHLO pv50p00im-hyfv10021501.me.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242012AbhKRCpq (ORCPT ); Wed, 17 Nov 2021 21:45:46 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=icloud.com; s=1a1hai; t=1637203006; bh=eLz6UTl5BLdUYofgE9brU1W96vGw23aT4QaPN/JuEV4=; h=From:To:Subject:Date:Message-Id:MIME-Version; b=hK2nvNHFXthOL6kRdXkiIUizo765ZaIHoV8zhcri6sokNYBks6195b3RZzv4wpwe6 AsSTBhAxBZnesPOBeetFytmF6ryAdIGvjKf4fqvNkF3rSjGSRoXAWFI4BNLJluGNvg 8uZ+4six2IRGfQM5A7pls16UUwf10CvL3N/30aiDNbTWEexA3o8uNw0ln0IHXwZfOy 2JG2oJvjKlAt6AkM8Ap4JvkRorAzxTG2Vj+pUySfsWaCsoP/ZaDrwdx2I+7aVs+aYH MpbJhdQCBovWyrtDWhOsBAruV50BFMe+ZF/rfwPwS2gHqTR/ybfHJ86HKsNfDFW4gq Ca6y6sA4Xa1uQ== Received: from localhost.localdomain (unknown [58.240.82.166]) by pv50p00im-hyfv10021501.me.com (Postfix) with ESMTPSA id 286A45406D4; Thu, 18 Nov 2021 02:36:44 +0000 (UTC) From: wangyangbo To: axboe@kernel.dk Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, wangyangbo Subject: [PATCH] loop: mask loop_control_ioctl parameter only as minor Date: Thu, 18 Nov 2021 10:36:40 +0800 Message-Id: <20211118023640.32559-1-yangbonis@icloud.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.425,18.0.790 definitions=2021-11-18_01:2021-11-17,2021-11-17 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-2009150000 definitions=main-2111180013 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org From: wangyangbo loop_control_ioctl call add_disk of block layer, but may pass number beyond MAX MINOR. So mask loop_control_ioctl parameter only as minor. Reproduce: touch file losetup /dev/loop1048576 file losetup /dev/loop0 file Problem: sysfs: cannot create duplicate filename '/dev/block/7:0' CPU: 0 PID: 529 Comm: losetup Not tainted 5.14.16-arch1-1 #1 ad87b876fa2ab6fdbd995dc1c9aab0ad8f767b2c Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack_lvl+0x46/0x5a sysfs_warn_dup.cold+0x17/0x24 sysfs_do_create_link_sd+0xbe/0xd0 device_add+0x580/0x970 ? dev_set_name+0x5b/0x80 __device_add_disk+0xb5/0x2f0 loop_add+0x236/0x290 [loop 2ed923fc8fbd84fdc093bf55ac085973636a3936] loop_control_ioctl+0x7f/0x1f0 [loop 2ed923fc8fbd84fdc093bf55ac085973636a3936] __x64_sys_ioctl+0x82/0xb0 do_syscall_64+0x5c/0x80 ? syscall_exit_to_user_mode+0x23/0x40 ? do_syscall_64+0x69/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7ff3e8ba259b Code: ff ff ff 85 c0 79 9b 49 c7 c4 ff ff ff ff 5b 5d 4c 89 e0 41 5c c3 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a5 a8 0c 00 f7 d8 64 89 01 48 RSP: 002b:00007ffe6d2eaa18 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffe6d2eb038 RCX: 00007ff3e8ba259b RDX: 0000000000000000 RSI: 0000000000004c80 RDI: 0000000000000003 RBP: 00007ffe6d2eaae0 R08: 1999999999999999 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 00007ffe6d2eaa24 R14: 0000560b131bd200 R15: 0000560b131c44a0 --- drivers/block/loop.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index a154cab6cd98..0d8240a7e66d 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -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)); case LOOP_CTL_REMOVE: - return loop_control_remove(parm); + return loop_control_remove(MINOR(parm)); case LOOP_CTL_GET_FREE: - return loop_control_get_free(parm); + return loop_control_get_free(MINOR(parm)); default: return -ENOSYS; } -- 2.20.1