EXT4-fs (loop5): VFS: Can't find ext4 filesystem
------------[ cut here ]------------
ODEBUG: free active (active state 0) object type: timer_list hint: rfcomm_dlc_timeout+0x0/0x70 include/linux/list.h:64
WARNING: CPU: 1 PID: 15711 at lib/debugobjects.c:329 debug_print_object+0x16a/0x210 lib/debugobjects.c:326
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 15711 Comm: syz-executor5 Not tainted 4.18.0-rc8+ #180
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+0x1c9/0x2b4 lib/dump_stack.c:113
 panic+0x238/0x4e7 kernel/panic.c:184
 __warn.cold.8+0x163/0x1ba kernel/panic.c:536
 report_bug+0x252/0x2d0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x1fc/0x4d0 arch/x86/kernel/traps.c:296
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992
RIP: 0010:debug_print_object+0x16a/0x210 lib/debugobjects.c:326
Code: 3a 87 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 92 00 00 00 48 8b 14 dd a0 74 3a 87 4c 89 f6 48 c7 c7 40 6a 3a 87 e8 16 af e6 fd <0f> 0b 83 05 79 e5 29 05 01 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f 
RSP: 0018:ffff88017e917648 EFLAGS: 00010086
RAX: 0000000000000000 RBX: 0000000000000003 RCX: ffffc9000541f000
RDX: 000000000002884c RSI: ffffffff81632481 RDI: 0000000000000001
RBP: ffff88017e917688 R08: ffff88019ba6e5c0 R09: ffffed003b623ec2
R10: ffffed003b623ec2 R11: ffff8801db11f617 R12: 0000000000000001
R13: ffffffff87f9c9e0 R14: ffffffff873a6ee0 R15: ffffffff816918c0
 __debug_check_no_obj_freed lib/debugobjects.c:783 [inline]
 debug_check_no_obj_freed+0x3b2/0x595 lib/debugobjects.c:815
 kfree+0xc7/0x260 mm/slab.c:3812
 rfcomm_dlc_free+0x1e/0x30 net/bluetooth/rfcomm/core.c:328
 rfcomm_dlc_put include/net/bluetooth/rfcomm.h:258 [inline]
 __rfcomm_create_dev net/bluetooth/rfcomm/tty.c:417 [inline]
 rfcomm_create_dev net/bluetooth/rfcomm/tty.c:486 [inline]
 rfcomm_dev_ioctl+0x1dfe/0x2240 net/bluetooth/rfcomm/tty.c:588
 rfcomm_sock_ioctl+0x89/0xb0 net/bluetooth/rfcomm/sock.c:902
 sock_do_ioctl+0xe4/0x3e0 net/socket.c:970
 sock_ioctl+0x30d/0x680 net/socket.c:1094
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:684
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701
 __do_sys_ioctl fs/ioctl.c:708 [inline]
 __se_sys_ioctl fs/ioctl.c:706 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456cb9
Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007fd409404c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fd4094056d4 RCX: 0000000000456cb9
RDX: 0000000020000140 RSI: 00000000400452c8 RDI: 0000000000000015
RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004ce500 R14: 00000000004c4e78 R15: 0000000000000001

======================================================
WARNING: possible circular locking dependency detected
4.18.0-rc8+ #180 Not tainted
------------------------------------------------------
syz-executor5/15711 is trying to acquire lock:
000000003f0447b6 ((console_sem).lock){-.-.}, at: down_trylock+0x13/0x70 kernel/locking/semaphore.c:136

but task is already holding lock:
00000000d9b60a86 (&obj_hash[i].lock){-.-.}, at: __debug_check_no_obj_freed lib/debugobjects.c:774 [inline]
00000000d9b60a86 (&obj_hash[i].lock){-.-.}, at: debug_check_no_obj_freed+0x16c/0x595 lib/debugobjects.c:815

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&obj_hash[i].lock){-.-.}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152
       __debug_object_init+0x127/0x12e0 lib/debugobjects.c:381
       debug_object_init+0x16/0x20 lib/debugobjects.c:429
       debug_hrtimer_init kernel/time/hrtimer.c:410 [inline]
       debug_init kernel/time/hrtimer.c:458 [inline]
       hrtimer_init+0x97/0x480 kernel/time/hrtimer.c:1308
       init_dl_task_timer+0x1b/0x50 kernel/sched/deadline.c:1056
       __sched_fork+0x2ae/0x590 kernel/sched/core.c:2185
       init_idle+0x75/0x7a0 kernel/sched/core.c:5405
       sched_init+0xbf3/0xd2c kernel/sched/core.c:6103
       start_kernel+0x47d/0x949 init/main.c:602
       x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:452
       x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:433
       secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:242

-> #2 (&rq->lock){-.-.}:
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144
       rq_lock kernel/sched/sched.h:1812 [inline]
       task_fork_fair+0x93/0x680 kernel/sched/fair.c:9952
       sched_fork+0x446/0xb40 kernel/sched/core.c:2381
       copy_process.part.39+0x1bf5/0x70b0 kernel/fork.c:1796
       copy_process kernel/fork.c:1639 [inline]
       _do_fork+0x291/0x12a0 kernel/fork.c:2122
       kernel_thread+0x34/0x40 kernel/fork.c:2181
       rest_init+0x22/0xe4 init/main.c:408
       start_kernel+0x90e/0x949 init/main.c:738
       x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:452
       x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:433
       secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:242

-> #1 (&p->pi_lock){-.-.}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152
       try_to_wake_up+0xd2/0x12a0 kernel/sched/core.c:1985
       wake_up_process+0x10/0x20 kernel/sched/core.c:2148
       __up.isra.1+0x1c0/0x2a0 kernel/locking/semaphore.c:262
       up+0x13c/0x1c0 kernel/locking/semaphore.c:187
       __up_console_sem+0xbe/0x1b0 kernel/printk/printk.c:242
       console_unlock+0x7a2/0x10b0 kernel/printk/printk.c:2411
       do_con_write+0x12cc/0x22a0 drivers/tty/vt/vt.c:2435
       con_write+0x25/0xc0 drivers/tty/vt/vt.c:2784
       process_output_block drivers/tty/n_tty.c:580 [inline]
       n_tty_write+0x6c1/0x11a0 drivers/tty/n_tty.c:2317
       do_tty_write drivers/tty/tty_io.c:963 [inline]
       tty_write+0x45f/0xae0 drivers/tty/tty_io.c:1051
       __vfs_write+0x117/0x9f0 fs/read_write.c:485
       vfs_write+0x1f8/0x560 fs/read_write.c:549
       ksys_write+0x101/0x260 fs/read_write.c:598
       __do_sys_write fs/read_write.c:610 [inline]
       __se_sys_write fs/read_write.c:607 [inline]
       __x64_sys_write+0x73/0xb0 fs/read_write.c:607
       do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #0 ((console_sem).lock){-.-.}:
       lock_acquire+0x1e4/0x540 kernel/locking/lockdep.c:3924
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152
       down_trylock+0x13/0x70 kernel/locking/semaphore.c:136
       __down_trylock_console_sem+0xae/0x200 kernel/printk/printk.c:225
       console_trylock+0x15/0xa0 kernel/printk/printk.c:2230
       console_trylock_spinning kernel/printk/printk.c:1643 [inline]
       vprintk_emit+0x6ad/0xdf0 kernel/printk/printk.c:1906
       vprintk_default+0x28/0x30 kernel/printk/printk.c:1948
       vprintk_func+0x7a/0xe7 kernel/printk/printk_safe.c:382
       printk+0xa7/0xcf kernel/printk/printk.c:1981
       __warn_printk+0x8c/0xe0 kernel/panic.c:590
       debug_print_object+0x16a/0x210 lib/debugobjects.c:326
       __debug_check_no_obj_freed lib/debugobjects.c:783 [inline]
       debug_check_no_obj_freed+0x3b2/0x595 lib/debugobjects.c:815
       kfree+0xc7/0x260 mm/slab.c:3812
       rfcomm_dlc_free+0x1e/0x30 net/bluetooth/rfcomm/core.c:328
       rfcomm_dlc_put include/net/bluetooth/rfcomm.h:258 [inline]
       __rfcomm_create_dev net/bluetooth/rfcomm/tty.c:417 [inline]
       rfcomm_create_dev net/bluetooth/rfcomm/tty.c:486 [inline]
       rfcomm_dev_ioctl+0x1dfe/0x2240 net/bluetooth/rfcomm/tty.c:588
       rfcomm_sock_ioctl+0x89/0xb0 net/bluetooth/rfcomm/sock.c:902
       sock_do_ioctl+0xe4/0x3e0 net/socket.c:970
       sock_ioctl+0x30d/0x680 net/socket.c:1094
       vfs_ioctl fs/ioctl.c:46 [inline]
       file_ioctl fs/ioctl.c:500 [inline]
       do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:684
       ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701
       __do_sys_ioctl fs/ioctl.c:708 [inline]
       __se_sys_ioctl fs/ioctl.c:706 [inline]
       __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706
       do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

other info that might help us debug this:

Chain exists of:
  (console_sem).lock --> &rq->lock --> &obj_hash[i].lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&obj_hash[i].lock);
                               lock(&rq->lock);
                               lock(&obj_hash[i].lock);
  lock((console_sem).lock);

 *** DEADLOCK ***

3 locks held by syz-executor5/15711:
 #0: 0000000098723bcb (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}, at: lock_sock include/net/sock.h:1474 [inline]
 #0: 0000000098723bcb (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}, at: rfcomm_sock_ioctl+0x7b/0xb0 net/bluetooth/rfcomm/sock.c:901
 #1: 00000000e314aef3 (rfcomm_ioctl_mutex){+.+.}, at: rfcomm_create_dev net/bluetooth/rfcomm/tty.c:485 [inline]
 #1: 00000000e314aef3 (rfcomm_ioctl_mutex){+.+.}, at: rfcomm_dev_ioctl+0x4a5/0x2240 net/bluetooth/rfcomm/tty.c:588
 #2: 00000000d9b60a86 (&obj_hash[i].lock){-.-.}, at: __debug_check_no_obj_freed lib/debugobjects.c:774 [inline]
 #2: 00000000d9b60a86 (&obj_hash[i].lock){-.-.}, at: debug_check_no_obj_freed+0x16c/0x595 lib/debugobjects.c:815

stack backtrace:
CPU: 1 PID: 15711 Comm: syz-executor5 Not tainted 4.18.0-rc8+ #180
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+0x1c9/0x2b4 lib/dump_stack.c:113
 print_circular_bug.isra.36.cold.57+0x1bd/0x27d kernel/locking/lockdep.c:1227
 check_prev_add kernel/locking/lockdep.c:1867 [inline]
 check_prevs_add kernel/locking/lockdep.c:1980 [inline]
 validate_chain kernel/locking/lockdep.c:2421 [inline]
 __lock_acquire+0x3449/0x5020 kernel/locking/lockdep.c:3435
 lock_acquire+0x1e4/0x540 kernel/locking/lockdep.c:3924
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152
 down_trylock+0x13/0x70 kernel/locking/semaphore.c:136
 __down_trylock_console_sem+0xae/0x200 kernel/printk/printk.c:225
 console_trylock+0x15/0xa0 kernel/printk/printk.c:2230
 console_trylock_spinning kernel/printk/printk.c:1643 [inline]
 vprintk_emit+0x6ad/0xdf0 kernel/printk/printk.c:1906
 vprintk_default+0x28/0x30 kernel/printk/printk.c:1948
 vprintk_func+0x7a/0xe7 kernel/printk/printk_safe.c:382
 printk+0xa7/0xcf kernel/printk/printk.c:1981
 __warn_printk+0x8c/0xe0 kernel/panic.c:590
 debug_print_object+0x16a/0x210 lib/debugobjects.c:326
 __debug_check_no_obj_freed lib/debugobjects.c:783 [inline]
 debug_check_no_obj_freed+0x3b2/0x595 lib/debugobjects.c:815
 kfree+0xc7/0x260 mm/slab.c:3812
 rfcomm_dlc_free+0x1e/0x30 net/bluetooth/rfcomm/core.c:328
 rfcomm_dlc_put include/net/bluetooth/rfcomm.h:258 [inline]
 __rfcomm_create_dev net/bluetooth/rfcomm/tty.c:417 [inline]
 rfcomm_create_dev net/bluetooth/rfcomm/tty.c:486 [inline]
 rfcomm_dev_ioctl+0x1dfe/0x2240 net/bluetooth/rfcomm/tty.c:588
 rfcomm_sock_ioctl+0x89/0xb0 net/bluetooth/rfcomm/sock.c:902
 sock_do_ioctl+0xe4/0x3e0 net/socket.c:970
 sock_ioctl+0x30d/0x680 net/socket.c:1094
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:684
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701
 __do_sys_ioctl fs/ioctl.c:708 [inline]
 __se_sys_ioctl fs/ioctl.c:706 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456cb9
Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007fd409404c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fd4094056d4 RCX: 0000000000456cb9
RDX: 0000000020000140 RSI: 00000000400452c8 RDI: 0000000000000015
RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004ce500 R14: 00000000004c4e78 R15: 0000000000000001
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..