print_req_error: I/O error, dev loop0, sector 0 ODEBUG: object is on stack, but not annotated WARNING: CPU: 1 PID: 19683 at lib/debugobjects.c:328 debug_object_is_on_stack lib/debugobjects.c:327 [inline] WARNING: CPU: 1 PID: 19683 at lib/debugobjects.c:328 __debug_object_init+0x60a/0x1040 lib/debugobjects.c:354 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 19683 Comm: syz-executor2 Not tainted 4.16.0-rc7+ #5 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 panic+0x1e4/0x41c kernel/panic.c:183 __warn+0x1dc/0x200 kernel/panic.c:547 report_bug+0x1f4/0x2b0 lib/bug.c:186 fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178 fixup_bug arch/x86/kernel/traps.c:247 [inline] do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:986 RIP: 0010:debug_object_is_on_stack lib/debugobjects.c:327 [inline] RIP: 0010:__debug_object_init+0x60a/0x1040 lib/debugobjects.c:354 RSP: 0018:ffff8801b1ae7968 EFLAGS: 00010082 RAX: 000000000000002d RBX: 0000000000000001 RCX: 0000000000000000 RDX: 000000000000002d RSI: ffffc90002862000 RDI: ffffed003635cf21 RBP: ffff8801b1ae7b40 R08: 0000000000000000 R09: 1ffff1003635ce89 R10: ffff8801b1ae7820 R11: ffffffff87b3b658 R12: ffff8801c8ce8340 R13: ffff8801b1ae7ca0 R14: ffff8801d7567ce8 R15: ffff8801d7567cf8 debug_object_init+0x17/0x20 lib/debugobjects.c:391 debug_hrtimer_init kernel/time/hrtimer.c:410 [inline] debug_init kernel/time/hrtimer.c:458 [inline] hrtimer_init+0x8c/0x410 kernel/time/hrtimer.c:1259 alarm_init kernel/time/alarmtimer.c:339 [inline] alarm_timer_nsleep+0x164/0x4d0 kernel/time/alarmtimer.c:787 SYSC_clock_nanosleep kernel/time/posix-timers.c:1227 [inline] SyS_clock_nanosleep+0x235/0x330 kernel/time/posix-timers.c:1205 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4548b9 RSP: 002b:00007f3b68b2fc68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 00007f3b68b306d4 RCX: 00000000004548b9 RDX: 0000000020001500 RSI: 0000040000000001 RDI: 0000000000000009 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020000180 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000004f R14: 00000000006f2808 R15: 0000000000000000 ====================================================== WARNING: possible circular locking dependency detected 4.16.0-rc7+ #5 Not tainted ------------------------------------------------------ syz-executor2/19683 is trying to acquire lock: ((console_sem).lock){-.-.}, at: [<0000000036ae966b>] down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 but task is already holding lock: (&obj_hash[i].lock){-.-.}, at: [<000000002c7768fd>] __debug_object_init+0x109/0x1040 lib/debugobjects.c:343 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+0x109/0x1040 lib/debugobjects.c:343 debug_object_init+0x17/0x20 lib/debugobjects.c:391 debug_hrtimer_init kernel/time/hrtimer.c:410 [inline] debug_init kernel/time/hrtimer.c:458 [inline] hrtimer_init+0x8c/0x410 kernel/time/hrtimer.c:1259 init_dl_task_timer+0x1b/0x50 kernel/sched/deadline.c:1060 __sched_fork+0x2bb/0xb60 kernel/sched/core.c:2189 init_idle+0x75/0x820 kernel/sched/core.c:5352 sched_init+0xb19/0xc43 kernel/sched/core.c:6049 start_kernel+0x452/0x819 init/main.c:586 x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:378 x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:359 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:239 -> #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:1760 [inline] task_fork_fair+0x7a/0x690 kernel/sched/fair.c:9471 sched_fork+0x450/0xc10 kernel/sched/core.c:2405 copy_process.part.38+0x17c9/0x4bd0 kernel/fork.c:1763 copy_process kernel/fork.c:1606 [inline] _do_fork+0x1f7/0xf70 kernel/fork.c:2087 kernel_thread+0x34/0x40 kernel/fork.c:2146 rest_init+0x22/0xf0 init/main.c:403 start_kernel+0x7f1/0x819 init/main.c:717 x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:378 x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:359 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:239 -> #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+0xbc/0x15f0 kernel/sched/core.c:1989 wake_up_process+0x10/0x20 kernel/sched/core.c:2152 __up.isra.0+0x1cc/0x2c0 kernel/locking/semaphore.c:262 up+0x13b/0x1d0 kernel/locking/semaphore.c:187 __up_console_sem+0xb2/0x1a0 kernel/printk/printk.c:242 console_unlock+0x5af/0xfb0 kernel/printk/printk.c:2417 do_con_write+0x106e/0x1f70 drivers/tty/vt/vt.c:2433 con_write+0x25/0xb0 drivers/tty/vt/vt.c:2782 process_output_block drivers/tty/n_tty.c:579 [inline] n_tty_write+0x5ef/0xec0 drivers/tty/n_tty.c:2308 do_tty_write drivers/tty/tty_io.c:958 [inline] tty_write+0x3fa/0x840 drivers/tty/tty_io.c:1042 __vfs_write+0xef/0x970 fs/read_write.c:480 vfs_write+0x189/0x510 fs/read_write.c:544 SYSC_write fs/read_write.c:589 [inline] SyS_write+0xef/0x220 fs/read_write.c:581 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #0 ((console_sem).lock){-.-.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920 __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+0xa2/0x1e0 kernel/printk/printk.c:225 console_trylock+0x15/0x70 kernel/printk/printk.c:2229 console_trylock_spinning kernel/printk/printk.c:1643 [inline] vprintk_emit+0x5b5/0xb90 kernel/printk/printk.c:1906 vprintk_default+0x28/0x30 kernel/printk/printk.c:1947 vprintk_func+0x57/0xc0 kernel/printk/printk_safe.c:379 printk+0xaa/0xca kernel/printk/printk.c:1980 debug_object_is_on_stack lib/debugobjects.c:325 [inline] __debug_object_init+0x5cc/0x1040 lib/debugobjects.c:354 debug_object_init+0x17/0x20 lib/debugobjects.c:391 debug_hrtimer_init kernel/time/hrtimer.c:410 [inline] debug_init kernel/time/hrtimer.c:458 [inline] hrtimer_init+0x8c/0x410 kernel/time/hrtimer.c:1259 alarm_init kernel/time/alarmtimer.c:339 [inline] alarm_timer_nsleep+0x164/0x4d0 kernel/time/alarmtimer.c:787 SYSC_clock_nanosleep kernel/time/posix-timers.c:1227 [inline] SyS_clock_nanosleep+0x235/0x330 kernel/time/posix-timers.c:1205 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 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 *** 1 lock held by syz-executor2/19683: #0: (&obj_hash[i].lock){-.-.}, at: [<000000002c7768fd>] __debug_object_init+0x109/0x1040 lib/debugobjects.c:343 stack backtrace: CPU: 1 PID: 19683 Comm: syz-executor2 Not tainted 4.16.0-rc7+ #5 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 print_circular_bug.isra.38+0x2cd/0x2dc kernel/locking/lockdep.c:1223 check_prev_add kernel/locking/lockdep.c:1863 [inline] check_prevs_add kernel/locking/lockdep.c:1976 [inline] validate_chain kernel/locking/lockdep.c:2417 [inline] __lock_acquire+0x30a8/0x3e00 kernel/locking/lockdep.c:3431 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920 __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+0xa2/0x1e0 kernel/printk/printk.c:225 console_trylock+0x15/0x70 kernel/printk/printk.c:2229 console_trylock_spinning kernel/printk/printk.c:1643 [inline] vprintk_emit+0x5b5/0xb90 kernel/printk/printk.c:1906 vprintk_default+0x28/0x30 kernel/printk/printk.c:1947 vprintk_func+0x57/0xc0 kernel/printk/printk_safe.c:379 printk+0xaa/0xca kernel/printk/printk.c:1980 debug_object_is_on_stack lib/debugobjects.c:325 [inline] __debug_object_init+0x5cc/0x1040 lib/debugobjects.c:354 debug_object_init+0x17/0x20 lib/debugobjects.c:391 debug_hrtimer_init kernel/time/hrtimer.c:410 [inline] debug_init kernel/time/hrtimer.c:458 [inline] hrtimer_init+0x8c/0x410 kernel/time/hrtimer.c:1259 alarm_init kernel/time/alarmtimer.c:339 [inline] alarm_timer_nsleep+0x164/0x4d0 kernel/time/alarmtimer.c:787 SYSC_clock_nanosleep kernel/time/posix-timers.c:1227 [inline] SyS_clock_nanosleep+0x235/0x330 kernel/time/posix-timers.c:1205 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4548b9 RSP: 002b:00007f3b68b2fc68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 00007f3b68b306d4 RCX: 00000000004548b9 RDX: 0000000020001500 RSI: 0000040000000001 RDI: 0000000000000009 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020000180 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000004f R14: 00000000006f2808 R15: 0000000000000000 Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 86400 seconds..