Hello, syzbot found the following issue on: HEAD commit: c3e0e1e23c70 Merge tag 'irq_urgent_for_v6.0' of git://git... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=14471d38880000 kernel config: https://syzkaller.appspot.com/x/.config?x=755695d26ad09807 dashboard link: https://syzkaller.appspot.com/bug?extid=f047480b1e906b46a3f4 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/67576e43d5c7/disk-c3e0e1e2.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/e568fb42b955/vmlinux-c3e0e1e2.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+f047480b1e906b46a3f4@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 6.0.0-rc7-syzkaller-00081-gc3e0e1e23c70 #0 Not tainted ------------------------------------------------------ kworker/u5:5/3650 is trying to acquire lock: ffff88807606c078 (&hdev->lock){+.+.}-{3:3}, at: discov_off+0x88/0x1a0 net/bluetooth/mgmt.c:1033 but task is already holding lock: ffffc90003f5fda8 ((work_completion)(&(&hdev->discov_off)->work)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 ((work_completion)(&(&hdev->discov_off)->work)){+.+.}-{0:0}: __flush_work+0x105/0xae0 kernel/workqueue.c:3069 __cancel_work_timer+0x3f9/0x570 kernel/workqueue.c:3160 mgmt_index_removed+0x218/0x340 net/bluetooth/mgmt.c:8952 hci_unregister_dev+0x34f/0x4e0 net/bluetooth/hci_core.c:2688 vhci_release+0x7c/0xf0 drivers/bluetooth/hci_vhci.c:568 __fput+0x277/0x9d0 fs/file_table.c:320 task_work_run+0xdd/0x1a0 kernel/task_work.c:177 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xad5/0x29b0 kernel/exit.c:795 do_group_exit+0xd2/0x2f0 kernel/exit.c:925 get_signal+0x238c/0x2610 kernel/signal.c:2857 arch_do_signal_or_restart+0x82/0x2300 arch/x86/kernel/signal.c:869 exit_to_user_mode_loop kernel/entry/common.c:166 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (&hdev->lock){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3829 [inline] __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5666 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12f/0x1350 kernel/locking/mutex.c:747 discov_off+0x88/0x1a0 net/bluetooth/mgmt.c:1033 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((work_completion)(&(&hdev->discov_off)->work)); lock(&hdev->lock); lock((work_completion)(&(&hdev->discov_off)->work)); lock(&hdev->lock); *** DEADLOCK *** 2 locks held by kworker/u5:5/3650: #0: ffff88807a95e938 ((wq_completion)hci0){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88807a95e938 ((wq_completion)hci0){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff88807a95e938 ((wq_completion)hci0){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff88807a95e938 ((wq_completion)hci0){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline] #0: ffff88807a95e938 ((wq_completion)hci0){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline] #0: ffff88807a95e938 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260 #1: ffffc90003f5fda8 ((work_completion)(&(&hdev->discov_off)->work)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264 stack backtrace: CPU: 0 PID: 3650 Comm: kworker/u5:5 Not tainted 6.0.0-rc7-syzkaller-00081-gc3e0e1e23c70 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 Workqueue: hci0 discov_off Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3829 [inline] __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5666 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12f/0x1350 kernel/locking/mutex.c:747 discov_off+0x88/0x1a0 net/bluetooth/mgmt.c:1033 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 </TASK> --- This report is generated by a bot. 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