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 X-Spam-Level: X-Spam-Status: No, score=-5.4 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 50D78C4CECE for ; Mon, 16 Sep 2019 13:29:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 285C9214DE for ; Mon, 16 Sep 2019 13:29:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733305AbfIPN3b (ORCPT ); Mon, 16 Sep 2019 09:29:31 -0400 Received: from mail-io1-f70.google.com ([209.85.166.70]:47638 "EHLO mail-io1-f70.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733237AbfIPN3N (ORCPT ); Mon, 16 Sep 2019 09:29:13 -0400 Received: by mail-io1-f70.google.com with SMTP id q1so32956598ios.14 for ; Mon, 16 Sep 2019 06:29:12 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:date:message-id:subject:from:to; bh=5ZUJhsqgpoCCn4jU5YhYsYU3T40C0q5cqL5dhqkQeqI=; b=hy9lrEliA6vOWrMtQWXH5r984sMqcUbiPpRVhCpHv2RS4eYsd2UmIVJoqOxvBCBmnu ApYOp6w8MD3HIdGKDYw6IbVdm4t3nExafLOonFHaC32a0XzwgMZ1OpJ7VxcpLzy6E5Dy pNrYsvY8JuqF98X5wmKQc1zXslW+wPGWgehdYcYh0D7gq47qpyMRwLdGc76A3dHL/YGJ mcUdfDmgtcaa2tRB0ugVfRUX2NaT6yztIQiC9QWXvOrCj/tL5Qw7Cgu1HIJrDr8vG7HI RTJzq8lHIfhM2IuUif8Qa9MgZY0qlsl6ekxU1sk1FhlFQmxJb6BZHEbOeiNbUuh4bLCY KdQA== X-Gm-Message-State: APjAAAWYGRZIR2A3g6vx8IBMyQeH1qHBs8GI56nX7a2h8GBUSOVYLusU j0oOszLrXwWPu6BGm75+ExrrIsY7RzUpuE8A7LiJ4LDegBct X-Google-Smtp-Source: APXvYqxQ8gS9JKu5CWGDi2n0HkCBaJx8dcwVaidIgtmT3OjfgEyCIjrTsgva7oqzsn38gzf+eOiHqX+HLatv4EQFuNGKozMclNNk MIME-Version: 1.0 X-Received: by 2002:a02:7797:: with SMTP id g145mr67307912jac.60.1568640552296; Mon, 16 Sep 2019 06:29:12 -0700 (PDT) Date: Mon, 16 Sep 2019 06:29:12 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000e669b80592ab96fc@google.com> Subject: possible deadlock in tower_open From: syzbot To: andreyknvl@google.com, gregkh@linuxfoundation.org, legousb-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, starblue@users.sourceforge.net, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: f0df5c1b usb-fuzzer: main usb gadget fuzzer driver git tree: https://github.com/google/kasan.git usb-fuzzer console output: https://syzkaller.appspot.com/x/log.txt?x=13c8d14e600000 kernel config: https://syzkaller.appspot.com/x/.config?x=5c6633fa4ed00be5 dashboard link: https://syzkaller.appspot.com/bug?extid=66935bec147fbf68d9f8 compiler: gcc (GCC) 9.0.0 20181231 (experimental) Unfortunately, I don't have any reproducer for this crash yet. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+66935bec147fbf68d9f8@syzkaller.appspotmail.com ====================================================== WARNING: possible circular locking dependency detected 5.3.0-rc7+ #0 Not tainted ------------------------------------------------------ syz-executor.1/8155 is trying to acquire lock: 0000000086c1bdfc (open_disc_mutex){+.+.}, at: tower_open+0xce/0x9b0 drivers/usb/misc/legousbtower.c:335 but task is already holding lock: 000000000f520f73 (minor_rwsem){++++}, at: usb_open+0x23/0x270 drivers/usb/core/file.c:39 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (minor_rwsem){++++}: down_write+0x92/0x150 kernel/locking/rwsem.c:1500 usb_deregister_dev+0x95/0x230 drivers/usb/core/file.c:239 tower_disconnect+0xa8/0x300 drivers/usb/misc/legousbtower.c:951 usb_unbind_interface+0x1bd/0x8a0 drivers/usb/core/driver.c:423 __device_release_driver drivers/base/dd.c:1134 [inline] device_release_driver_internal+0x42f/0x500 drivers/base/dd.c:1165 bus_remove_device+0x2dc/0x4a0 drivers/base/bus.c:556 device_del+0x420/0xb10 drivers/base/core.c:2339 usb_disable_device+0x211/0x690 drivers/usb/core/message.c:1237 usb_disconnect+0x284/0x8d0 drivers/usb/core/hub.c:2199 hub_port_connect drivers/usb/core/hub.c:4949 [inline] hub_port_connect_change drivers/usb/core/hub.c:5213 [inline] port_event drivers/usb/core/hub.c:5359 [inline] hub_event+0x1454/0x3640 drivers/usb/core/hub.c:5441 process_one_work+0x92b/0x1530 kernel/workqueue.c:2269 worker_thread+0x96/0xe20 kernel/workqueue.c:2415 kthread+0x318/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 -> #0 (open_disc_mutex){+.+.}: check_prev_add kernel/locking/lockdep.c:2405 [inline] check_prevs_add kernel/locking/lockdep.c:2507 [inline] validate_chain kernel/locking/lockdep.c:2897 [inline] __lock_acquire+0x1f7c/0x3b50 kernel/locking/lockdep.c:3880 lock_acquire+0x127/0x320 kernel/locking/lockdep.c:4412 __mutex_lock_common kernel/locking/mutex.c:930 [inline] __mutex_lock+0x158/0x1360 kernel/locking/mutex.c:1077 tower_open+0xce/0x9b0 drivers/usb/misc/legousbtower.c:335 usb_open+0x1df/0x270 drivers/usb/core/file.c:48 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x494/0x1120 fs/open.c:797 do_last fs/namei.c:3416 [inline] path_openat+0x1430/0x3f50 fs/namei.c:3533 do_filp_open+0x1a1/0x280 fs/namei.c:3563 do_sys_open+0x3c0/0x580 fs/open.c:1089 do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(minor_rwsem); lock(open_disc_mutex); lock(minor_rwsem); lock(open_disc_mutex); *** DEADLOCK *** 1 lock held by syz-executor.1/8155: #0: 000000000f520f73 (minor_rwsem){++++}, at: usb_open+0x23/0x270 drivers/usb/core/file.c:39 stack backtrace: CPU: 0 PID: 8155 Comm: syz-executor.1 Not tainted 5.3.0-rc7+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xca/0x13e lib/dump_stack.c:113 check_noncircular+0x345/0x3e0 kernel/locking/lockdep.c:1741 check_prev_add kernel/locking/lockdep.c:2405 [inline] check_prevs_add kernel/locking/lockdep.c:2507 [inline] validate_chain kernel/locking/lockdep.c:2897 [inline] __lock_acquire+0x1f7c/0x3b50 kernel/locking/lockdep.c:3880 lock_acquire+0x127/0x320 kernel/locking/lockdep.c:4412 __mutex_lock_common kernel/locking/mutex.c:930 [inline] __mutex_lock+0x158/0x1360 kernel/locking/mutex.c:1077 tower_open+0xce/0x9b0 drivers/usb/misc/legousbtower.c:335 usb_open+0x1df/0x270 drivers/usb/core/file.c:48 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x494/0x1120 fs/open.c:797 do_last fs/namei.c:3416 [inline] path_openat+0x1430/0x3f50 fs/namei.c:3533 do_filp_open+0x1a1/0x280 fs/namei.c:3563 do_sys_open+0x3c0/0x580 fs/open.c:1089 do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4137d1 Code: 75 14 b8 02 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 19 00 00 c3 48 83 ec 08 e8 0a fa ff ff 48 89 04 24 b8 02 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fa ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007f56184c17a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 6666666666666667 RCX: 00000000004137d1 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007f56184c1850 RBP: 000000000075c070 R08: 000000000000000f R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00007f56184c26d4 R13: 00000000004c8cab R14: 00000000004dfc78 R15: 00000000ffffffff --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.