From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-io1-f72.google.com (mail-io1-f72.google.com [209.85.166.72]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 81EA73BBFB for ; Thu, 29 Feb 2024 07:51:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.72 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709193065; cv=none; b=OpcYKoXiXP4z39H2gNjBFFcmwow4uajBYsjhGsLxGvx1gdF1iPsVuZKfzuszWlX/WHHxOd7J9MsXkwAmJeJX4kQ3ZAo9xhzOG2OLzLByyxkm7VeoJsWd/RP+t7Mpilp7ruFvVDkLs7OPVVDSDbF5EKAAM3Kpnas2suNKj37dsLA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709193065; c=relaxed/simple; bh=UTzIZHh312FQNv3tRh7qf5GzLXbBMBW+MciNmJj0JrQ=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=Joy6meHNllibB0FlYp8gC8VgnH7+1oY8NkVhevJTioDU93+S4OKQvzhjDMxFYNX4qwC7FKocvFJYrTFWJrbEYTWvDZv2jI4YiFQxIvMsJRmiz3LrKX5wZBdBahyGHSQulCPoExgPvpdwwoopiIhzm76tRMvFqucZ2L35Bsc9IFU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.166.72 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-io1-f72.google.com with SMTP id ca18e2360f4ac-7c78505a39eso77903039f.1 for ; Wed, 28 Feb 2024 23:51:03 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1709193062; x=1709797862; h=to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=s8U5P0GXuc+YHZ9MbzKcsIkuCHeeUzRRswz+LIBm/r4=; b=kUEEpUa2yCT/bUQMK5CyufoC5OE9sCr8XA8vIIuss6UTaUgVI+4YiHtgdcI5XL6L8w kVYw+qNMpd79o4NEsXt5gK4xFXdPZLBpz78zLAMxeqRQajyvr3+CAvqkA7nObODUuX3W OifGtRgie0zFcoyjSkvPKrnlvNYPjh8V+Bii0FKc3Z0qpCRGN/lYUM8IK3A1BoeDO0iV 2xWQSRNTK8bVFzCasocgcS1a+f69XmW6iP+iKtLKtwvosyuCWgW0XDqdc/7pLabLI34X as3Vrjyy8PP4cNJOwWcHjmJlM19NvQ/1yoO1nMZb1HguiqJnxQln+H0VcWxNd3EjaHcg j1tQ== X-Gm-Message-State: AOJu0YyHON2cha06CpEsm+uXa6SHZqi0yd7tdbVMaSHTzewjcocYOyCB rxwvcCgbT5o/9kh/yuaKfCe8nfYP6ytGoTWC+e7FKLjfOnu+1rmcO/91RuZl1gYkYIP2RvOy4ac fQaj57lCOn6Wa3rloVaEkcByKkt/LtDeTvCt9RMG3A8etjQap4VlGUcBj7g== X-Google-Smtp-Source: AGHT+IGZxVsOU/D5iC1fida8wWele+lavnBb7G4muhKPLrv4qzTwuiGzIzwM7/qRigSMZj2TrEc7YLcZqTfzdDqmwYlOHC7kJFpL Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a92:c564:0:b0:365:bcee:5dc0 with SMTP id b4-20020a92c564000000b00365bcee5dc0mr109849ilj.3.1709193062649; Wed, 28 Feb 2024 23:51:02 -0800 (PST) Date: Wed, 28 Feb 2024 23:51:02 -0800 In-Reply-To: <20240229072016.186240-1-lizhi.xu@windriver.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000005a1ac1061280857e@google.com> Subject: Re: [syzbot] [media?] [usb?] INFO: task hung in vb2_video_unregister_device From: syzbot To: linux-kernel@vger.kernel.org, lizhi.xu@windriver.com, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: possible deadlock in vb2_video_unregister_device usb 1-1: config 0 descriptor?? usbtv 1-1:0.0: Fushicai USBTV007 Audio-Video Grabber usb 1-1: USB disconnect, device number 2 ============================================ WARNING: possible recursive locking detected 6.8.0-rc6-syzkaller-g805d849d7c3c-dirty #0 Not tainted -------------------------------------------- kworker/0:4/6186 is trying to acquire lock: ffff0000cd544b90 (&usbtv->vb2q_lock){+.+.}-{3:3}, at: vb2_video_unregister_device+0xe8/0x1ac drivers/media/common/videobuf2/videobuf2-v4l2.c:1268 but task is already holding lock: ffff0000cd544b90 (&usbtv->vb2q_lock){+.+.}-{3:3}, at: usbtv_video_free+0x2c/0x84 drivers/media/usb/usbtv/usbtv-video.c:966 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&usbtv->vb2q_lock); lock(&usbtv->vb2q_lock); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by kworker/0:4/6186: #0: ffff0000c252f138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x560/0x1204 kernel/workqueue.c:2606 #1: ffff800097b77c20 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x5a0/0x1204 kernel/workqueue.c:2608 #2: ffff0000ccf38190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:990 [inline] #2: ffff0000ccf38190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1b4/0x435c drivers/usb/core/hub.c:5811 #3: ffff0000c73fb190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:990 [inline] #3: ffff0000c73fb190 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0xec/0x808 drivers/usb/core/hub.c:2258 #4: ffff0000d811b160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:990 [inline] #4: ffff0000d811b160 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff0000d811b160 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xbc/0x6a0 drivers/base/dd.c:1292 #5: ffff0000cd544b90 (&usbtv->vb2q_lock){+.+.}-{3:3}, at: usbtv_video_free+0x2c/0x84 drivers/media/usb/usbtv/usbtv-video.c:966 #6: ffff0000cd544b00 (&usbtv->v4l2_lock){+.+.}-{3:3}, at: usbtv_video_free+0x3c/0x84 drivers/media/usb/usbtv/usbtv-video.c:967 stack backtrace: CPU: 0 PID: 6186 Comm: kworker/0:4 Not tainted 6.8.0-rc6-syzkaller-g805d849d7c3c-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Workqueue: usb_hub_wq hub_event Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:291 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:298 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106 dump_stack+0x1c/0x28 lib/dump_stack.c:113 print_deadlock_bug+0x4e4/0x660 kernel/locking/lockdep.c:3012 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain kernel/locking/lockdep.c:3856 [inline] __lock_acquire+0x5fe4/0x763c kernel/locking/lockdep.c:5137 lock_acquire+0x23c/0x71c kernel/locking/lockdep.c:5754 __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:608 __mutex_lock kernel/locking/mutex.c:752 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:804 vb2_video_unregister_device+0xe8/0x1ac drivers/media/common/videobuf2/videobuf2-v4l2.c:1268 usbtv_video_free+0x4c/0x84 drivers/media/usb/usbtv/usbtv-video.c:970 usbtv_disconnect+0x6c/0xc4 drivers/media/usb/usbtv/usbtv-core.c:138 usb_unbind_interface+0x1a4/0x758 drivers/usb/core/driver.c:461 device_remove drivers/base/dd.c:569 [inline] __device_release_driver drivers/base/dd.c:1272 [inline] device_release_driver_internal+0x440/0x6a0 drivers/base/dd.c:1295 device_release_driver+0x28/0x38 drivers/base/dd.c:1318 bus_remove_device+0x314/0x3b4 drivers/base/bus.c:574 device_del+0x480/0x87c drivers/base/core.c:3828 usb_disable_device+0x354/0x760 drivers/usb/core/message.c:1416 usb_disconnect+0x290/0x808 drivers/usb/core/hub.c:2267 hub_port_connect drivers/usb/core/hub.c:5323 [inline] hub_port_connect_change drivers/usb/core/hub.c:5623 [inline] port_event drivers/usb/core/hub.c:5783 [inline] hub_event+0x18ec/0x435c drivers/usb/core/hub.c:5865 process_one_work+0x694/0x1204 kernel/workqueue.c:2633 process_scheduled_works kernel/workqueue.c:2706 [inline] worker_thread+0x970/0xef4 kernel/workqueue.c:2787 kthread+0x288/0x310 kernel/kthread.c:388 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 Tested on: commit: 805d849d Merge tag 'acpi-6.8-rc7' of git://git.kernel... git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master console output: https://syzkaller.appspot.com/x/log.txt?x=12b53522180000 kernel config: https://syzkaller.appspot.com/x/.config?x=e412105d06db24c2 dashboard link: https://syzkaller.appspot.com/bug?extid=2622b51b35f91a00ea18 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 userspace arch: arm64 patch: https://syzkaller.appspot.com/x/patch.diff?x=17181132180000