From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f198.google.com (mail-il1-f198.google.com [209.85.166.198]) (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 C59B064A for ; Tue, 26 Nov 2024 00:01:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.198 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732579289; cv=none; b=pIZfnGr+BORjiRvUdLxoVG6QC5MphqWolFZ2LBjuo3Pw4YHjpBbhJki5KgH8ixuFMCjY+pCpOf9A90LoPWn4Ci25JqI4qZ2IVAG8w/ydJeb3Upw6DFtXR8XXttFdWI68pErVjIKhGh7RvVUhfW6JKOhjkWM+vp8twwigC77ymm8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732579289; c=relaxed/simple; bh=zxM6zYZhc4zVuFVg7hX5SOalPZ8wa3jgGbf9xz0kQEA=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=T56iu+KCtkmQrEIsqrrSkGvo+TicT2HMYiGjrEhQib2JWNEl0l5fim+/kZxVbuij+qy7fB5UEdeWieAkD6hOylagOcKmypXsH7eGbHJhlBReIZV9OhId4MstAaBIgX92myq4ZCGU4Azky/fp44n1QrCaZHjd6slJvAvkdzXZF8E= 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=209.85.166.198 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-il1-f198.google.com with SMTP id e9e14a558f8ab-3a7634d8538so43455575ab.0 for ; Mon, 25 Nov 2024 16:01:25 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1732579285; x=1733184085; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=92USXR7bbQYiLfixUHSYEdokYc7CucAYCL5IOWlbYNA=; b=ucSnvCmiDak+Lp1KLeNwYUhLgDPK91tBN8yKoMpoTfhjTpgDCq2TSN4VKC2vAN+QlW fxcxq6AKWoqnXcg2WSVDph/ghKDhrNCxXpNvC/aBphwFUNUellMjBLtwCE3n1iZg9frX pbpxL1XVP37aYUtDp9bKMMFK1u12YZsTTN8j66amUKznFnGQ8grPZoG3dFtF7FoIcpd7 Zbx7I/MsLe126XnMFRxHEG07b06tehS3dpDvxvrQk//bLc5ieDJqg4DJZ/yPMUnLNYgk zOaN5kZ/8B7jw39sWgp7XDcwBnuuK4TTAlwh/zBrtG1imkxnpHPK/VaKPA/LNKcwRVDd /PRQ== X-Forwarded-Encrypted: i=1; AJvYcCW8AqgWiAfiERDR5eT3CvQ+nRc+E0RBdo9B+lS0dn3rCBHbAwqybK3DYDv4YrIVL4dihsoAGmFu7MuX3Bo=@vger.kernel.org X-Gm-Message-State: AOJu0Yx7DTNQD95ciwZeYResChPcGfWYIxEDUt56K0kU6b6GaIoGGo/h FAW1gOlOCgrdSgI/jsUK+bQxQan7norqgd2KjZpwgH/+X1/AJ18wXjupCuZRLaO5NhiTNQdQv1b I2KFOpO9XOIVPotq6J1vI5Ebm8/oOSr5tAk3KMD0vNOsxo+OdiZi5864= X-Google-Smtp-Source: AGHT+IFqcsdHv6IjMuU/R1rl0DNH9CgIV9rsgV7+axQwgKp5az8bgT2RDKtTz2YvTiaFlbCjgXNAy7KN5hYv4tyjiuPxlz5Rc8Qq Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:12cc:b0:3a7:2204:c83e with SMTP id e9e14a558f8ab-3a79ae044b4mr160710885ab.10.1732579285007; Mon, 25 Nov 2024 16:01:25 -0800 (PST) Date: Mon, 25 Nov 2024 16:01:24 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <67450fd4.050a0220.1286eb.0007.GAE@google.com> Subject: [syzbot] [block?] possible deadlock in blk_unregister_queue From: syzbot To: axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 9f16d5e6f220 Merge tag 'for-linus' of git://git.kernel.org.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=15542778580000 kernel config: https://syzkaller.appspot.com/x/.config?x=7393f07275e8e571 dashboard link: https://syzkaller.appspot.com/bug?extid=91585b36b538053343e4 compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-9f16d5e6.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/8a4ab7536099/vmlinux-9f16d5e6.xz kernel image: https://storage.googleapis.com/syzbot-assets/a94d1bc43eff/bzImage-9f16d5e6.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+91585b36b538053343e4@syzkaller.appspotmail.com ====================================================== WARNING: possible circular locking dependency detected 6.12.0-syzkaller-09073-g9f16d5e6f220 #0 Not tainted ------------------------------------------------------ kworker/0:0/8 is trying to acquire lock: ffff88802671fb38 (&q->sysfs_lock){+.+.}-{4:4}, at: blk_unregister_queue+0x125/0x2e0 block/blk-sysfs.c:869 but task is already holding lock: ffff88802671fbc8 (&q->sysfs_dir_lock){+.+.}-{4:4}, at: blk_unregister_queue+0xdb/0x2e0 block/blk-sysfs.c:860 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&q->sysfs_dir_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xa60 kernel/locking/mutex.c:735 blk_mq_sysfs_unregister_hctxs+0x92/0x2d0 block/blk-mq-sysfs.c:278 __blk_mq_update_nr_hw_queues+0x93f/0x14e0 block/blk-mq.c:4930 blk_mq_update_nr_hw_queues+0x2a/0x40 block/blk-mq.c:4985 nbd_start_device+0x15b/0xd70 drivers/block/nbd.c:1413 nbd_start_device_ioctl drivers/block/nbd.c:1464 [inline] __nbd_ioctl drivers/block/nbd.c:1539 [inline] nbd_ioctl+0x21a/0xfd0 drivers/block/nbd.c:1579 blkdev_ioctl+0x276/0x6d0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #4 (&q->q_usage_counter(io)#49){++++}-{0:0}: bio_queue_enter block/blk.h:75 [inline] blk_mq_submit_bio+0x1fb6/0x24c0 block/blk-mq.c:3092 __submit_bio+0x384/0x540 block/blk-core.c:629 __submit_bio_noacct_mq block/blk-core.c:710 [inline] submit_bio_noacct_nocheck+0x698/0xd70 block/blk-core.c:739 submit_bio_noacct+0x93a/0x1e20 block/blk-core.c:868 submit_bh fs/buffer.c:2819 [inline] block_read_full_folio+0x812/0xa50 fs/buffer.c:2446 filemap_read_folio+0xc6/0x2a0 mm/filemap.c:2366 filemap_update_page mm/filemap.c:2450 [inline] filemap_get_pages+0x155f/0x1be0 mm/filemap.c:2571 filemap_read+0x3ca/0xd70 mm/filemap.c:2646 blkdev_read_iter+0x187/0x480 block/fops.c:767 new_sync_read fs/read_write.c:484 [inline] vfs_read+0x87f/0xbe0 fs/read_write.c:565 ksys_read+0x12b/0x250 fs/read_write.c:708 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (mapping.invalidate_lock#2){++++}-{4:4} : down_read+0x9a/0x330 kernel/locking/rwsem.c:1524 filemap_invalidate_lock_shared include/linux/fs.h:873 [inline] filemap_fault+0x2e0/0x2820 mm/filemap.c:3332 __do_fault+0x10a/0x490 mm/memory.c:4907 do_shared_fault mm/memory.c:5386 [inline] do_fault mm/memory.c:5460 [inline] do_pte_missing+0x1a8/0x3e70 mm/memory.c:3979 handle_pte_fault mm/memory.c:5801 [inline] __handle_mm_fault+0x103c/0x2a40 mm/memory.c:5944 handle_mm_fault+0x3fa/0xaa0 mm/memory.c:6112 faultin_page mm/gup.c:1187 [inline] __get_user_pages+0x8d9/0x3b50 mm/gup.c:1485 __get_user_pages_locked mm/gup.c:1751 [inline] faultin_page_range+0x24a/0x980 mm/gup.c:1975 madvise_populate mm/madvise.c:951 [inline] do_madvise+0x504/0x770 mm/madvise.c:1681 __do_sys_madvise mm/madvise.c:1700 [inline] __se_sys_madvise mm/madvise.c:1698 [inline] __x64_sys_madvise+0xa9/0x110 mm/madvise.c:1698 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&mm->mmap_lock){++++}-{4:4}: __might_fault mm/memory.c:6751 [inline] __might_fault+0x11b/0x190 mm/memory.c:6744 _inline_copy_from_user include/linux/uaccess.h:162 [inline] _copy_from_user+0x29/0xd0 lib/usercopy.c:18 copy_from_user include/linux/uaccess.h:212 [inline] __blk_trace_setup+0xa8/0x180 kernel/trace/blktrace.c:626 blk_trace_setup+0x47/0x70 kernel/trace/blktrace.c:648 sg_ioctl_common drivers/scsi/sg.c:1121 [inline] sg_ioctl+0x65e/0x2750 drivers/scsi/sg.c:1163 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&q->debugfs_mutex){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xa60 kernel/locking/mutex.c:735 blk_register_queue+0x13c/0x550 block/blk-sysfs.c:774 add_disk_fwnode+0x785/0x1300 block/genhd.c:493 add_disk include/linux/blkdev.h:751 [inline] brd_alloc.isra.0+0x5a2/0x840 drivers/block/brd.c:399 brd_init+0x12b/0x1d0 drivers/block/brd.c:479 do_one_initcall+0x128/0x700 init/main.c:1266 do_initcall_level init/main.c:1328 [inline] do_initcalls init/main.c:1344 [inline] do_basic_setup init/main.c:1363 [inline] kernel_init_freeable+0x5c7/0x900 init/main.c:1577 kernel_init+0x1c/0x2b0 init/main.c:1466 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #0 (&q->sysfs_lock){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain kernel/locking/lockdep.c:3904 [inline] __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5226 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xa60 kernel/locking/mutex.c:735 blk_unregister_queue+0x125/0x2e0 block/blk-sysfs.c:869 del_gendisk+0x2de/0xb20 block/genhd.c:710 md_kobj_release+0xb2/0x100 drivers/md/md.c:5742 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1e4/0x5a0 lib/kobject.c:737 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 other info that might help us debug this: Chain exists of: &q->sysfs_lock --> &q->q_usage_counter(io)#49 --> &q->sysfs_dir_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&q->sysfs_dir_lock); lock(&q->q_usage_counter(io)#49); lock(&q->sysfs_dir_lock); lock(&q->sysfs_lock); *** DEADLOCK *** 3 locks held by kworker/0:0/8: #0: ffff88801c79fd48 ((wq_completion)md_misc){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3204 #1: ffffc900000b7d80 ((work_completion)(&mddev->del_work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff88802671fbc8 (&q->sysfs_dir_lock){+.+.}-{4:4}, at: blk_unregister_queue+0xdb/0x2e0 block/blk-sysfs.c:860 stack backtrace: CPU: 0 UID: 0 PID: 8 Comm: kworker/0:0 Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: md_misc mddev_delayed_delete Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x419/0x5d0 kernel/locking/lockdep.c:2074 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2206 check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain kernel/locking/lockdep.c:3904 [inline] __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5226 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xa60 kernel/locking/mutex.c:735 blk_unregister_queue+0x125/0x2e0 block/blk-sysfs.c:869 del_gendisk+0x2de/0xb20 block/genhd.c:710 md_kobj_release+0xb2/0x100 drivers/md/md.c:5742 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1e4/0x5a0 lib/kobject.c:737 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 --- This report 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 issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup