syz-executor.4: attempt to access beyond end of device loop4: rw=2049, sector=124, nr_sectors = 4 limit=40 Buffer I/O error on dev loop4, logical block 31, lost async page write ====================================================== WARNING: possible circular locking dependency detected 6.2.0-next-20230224 #1 Not tainted ------------------------------------------------------ syz-executor.0/276 is trying to acquire lock: ffff88800fdf4880 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: __flush_work+0xdd/0xd80 but task is already holding lock: ffff88800fdf4920 (&hdev->cmd_sync_work_lock){+.+.}-{3:3}, at: hci_cmd_sync_clear+0x45/0x250 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&hdev->cmd_sync_work_lock){+.+.}-{3:3}: __mutex_lock+0x133/0x14a0 hci_cmd_sync_work+0x1e6/0x320 process_one_work+0xa0f/0x1790 worker_thread+0x63b/0x1260 kthread+0x2e9/0x3a0 ret_from_fork+0x2c/0x50 -> #0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}: __lock_acquire+0x2d56/0x6380 lock_acquire.part.0+0xea/0x320 __flush_work+0x109/0xd80 __cancel_work_timer+0x39c/0x4e0 hci_cmd_sync_clear+0x52/0x250 hci_unregister_dev+0xf9/0x410 vhci_release+0x80/0x100 __fput+0x263/0xa40 task_work_run+0x174/0x280 do_exit+0xad8/0x2800 do_group_exit+0xd4/0x2a0 get_signal+0x23c8/0x2450 arch_do_signal_or_restart+0x79/0x590 exit_to_user_mode_prepare+0x122/0x190 syscall_exit_to_user_mode+0x1d/0x50 do_syscall_64+0x4c/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&hdev->cmd_sync_work_lock); lock((work_completion)(&hdev->cmd_sync_work)); lock(&hdev->cmd_sync_work_lock); lock((work_completion)(&hdev->cmd_sync_work)); *** DEADLOCK *** 1 lock held by syz-executor.0/276: #0: ffff88800fdf4920 (&hdev->cmd_sync_work_lock){+.+.}-{3:3}, at: hci_cmd_sync_clear+0x45/0x250 stack backtrace: CPU: 0 PID: 276 Comm: syz-executor.0 Not tainted 6.2.0-next-20230224 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack_lvl+0x91/0xf0 check_noncircular+0x263/0x2e0 __lock_acquire+0x2d56/0x6380 lock_acquire.part.0+0xea/0x320 __flush_work+0x109/0xd80 __cancel_work_timer+0x39c/0x4e0 hci_cmd_sync_clear+0x52/0x250 hci_unregister_dev+0xf9/0x410 vhci_release+0x80/0x100 __fput+0x263/0xa40 task_work_run+0x174/0x280 do_exit+0xad8/0x2800 do_group_exit+0xd4/0x2a0 get_signal+0x23c8/0x2450 arch_do_signal_or_restart+0x79/0x590 exit_to_user_mode_prepare+0x122/0x190 syscall_exit_to_user_mode+0x1d/0x50 do_syscall_64+0x4c/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc RIP: 0033:0x7fd1501d813a Code: Unable to access opcode bytes at 0x7fd1501d8110. RSP: 002b:00007ffc58f78708 EFLAGS: 00000246 ORIG_RAX: 0000000000000037 RAX: fffffffffffffe00 RBX: 0000000000000000 RCX: 00007fd1501d813a RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000003 R08: 00007ffc58f7873c R09: ffffffffffff0000 R10: 00007fd1502ba3e8 R11: 0000000000000246 R12: 00007ffc58f7873c R13: 00007fd15023a3b2 R14: 00007fd1502ba3e8 R15: 00007fd1502ba3e0 FAT-fs (loop1): bogus number of reserved sectors FAT-fs (loop1): Can't find a valid FAT filesystem cgroup2: Unknown parameter 'io' Bluetooth: hci1: unexpected cc 0x0c03 length: 249 > 1 Bluetooth: hci1: unexpected cc 0x1003 length: 249 > 9 Bluetooth: hci1: unexpected cc 0x1001 length: 249 > 9 Bluetooth: hci1: unexpected cc 0x0c23 length: 249 > 4 Bluetooth: hci1: unexpected cc 0x0c25 length: 249 > 3 Bluetooth: hci1: unexpected cc 0x0c38 length: 249 > 2 Bluetooth: hci5: unexpected cc 0x0c03 length: 249 > 1 Bluetooth: hci5: unexpected cc 0x1003 length: 249 > 9 Bluetooth: hci5: unexpected cc 0x1001 length: 249 > 9 Bluetooth: hci5: unexpected cc 0x0c23 length: 249 > 4 Bluetooth: hci5: unexpected cc 0x0c25 length: 249 > 3 Bluetooth: hci5: unexpected cc 0x0c38 length: 249 > 2 Bluetooth: hci0: Opcode 0x c03 failed: -110 Bluetooth: hci1: command 0x0409 tx timeout Bluetooth: hci2: Opcode 0x c03 failed: -110 Bluetooth: hci5: command 0x0409 tx timeout Bluetooth: hci1: command 0x041b tx timeout Bluetooth: hci5: command 0x041b tx timeout Bluetooth: hci0: unexpected cc 0x0c03 length: 249 > 1 Bluetooth: hci0: unexpected cc 0x1003 length: 249 > 9 Bluetooth: hci0: unexpected cc 0x1001 length: 249 > 9 Bluetooth: hci0: unexpected cc 0x0c23 length: 249 > 4 Bluetooth: hci0: unexpected cc 0x0c25 length: 249 > 3 Bluetooth: hci0: unexpected cc 0x0c38 length: 249 > 2 Bluetooth: hci2: unexpected cc 0x0c03 length: 249 > 1 Bluetooth: hci2: unexpected cc 0x1003 length: 249 > 9 Bluetooth: hci2: unexpected cc 0x1001 length: 249 > 9 Bluetooth: hci2: unexpected cc 0x0c23 length: 249 > 4 Bluetooth: hci2: unexpected cc 0x0c25 length: 249 > 3 Bluetooth: hci2: unexpected cc 0x0c38 length: 249 > 2 Bluetooth: hci1: command 0x040f tx timeout Bluetooth: hci5: command 0x040f tx timeout Bluetooth: hci0: command 0x0409 tx timeout Bluetooth: hci2: command 0x0409 tx timeout