------------[ cut here ]------------
ODEBUG: deactivate not available (active state 0) object type: hrtimer hint: tick_sched_timer+0x0/0x130 kernel/time/tick-sched.c:66
PANIC: double fault, error_code: 0x0
WARNING: CPU: 1 PID: 51 at lib/debugobjects.c:329 debug_print_object+0x16a/0x210 lib/debugobjects.c:326
CPU: 0 PID: 8073 Comm: syz-executor3 Not tainted 4.20.0-rc2+ #294
Kernel panic - not syncing: panic_on_warn set ...
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
CPU: 1 PID: 51 Comm: kworker/u4:2 Not tainted 4.20.0-rc2+ #294
RIP: 0010:__udp4_lib_lookup+0x25/0x870 net/ipv4/udp.c:466
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Code: ff 0f 1f 40 00 55 48 89 e5 41 57 41 56 41 55 49 bd 00 00 00 00 00 fc ff df 41 54 53 44 89 c3 48 81 ec 00 01 00 00 48 8b 45 20 <48> 89 bd 28 ff ff ff 66 c1 c3 08 4c 8b 65 18 89 b5 1c ff ff ff 89
Workqueue: netns cleanup_net
RSP: 0018:ffff8881d9bfcf98 EFLAGS: 00010282
Call Trace:
RAX: 0000000000000000 RBX: 000000000000e4c7 RCX: 00000000111414ac
 <IRQ>
RDX: 000000000000244e RSI: 000000000100007f RDI: ffff8881b83f0100
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x244/0x39d lib/dump_stack.c:113
RBP: ffff8881d9bfd0c0 R08: 000000000000e4c7 R09: 0000000000000001
R10: 0000000000000000 R11: ffff8881dae2db3b R12: ffff8881bef83800
 panic+0x2ad/0x55c kernel/panic.c:188
R13: dffffc0000000000 R14: ffff8881bef837ec R15: 0000000000000003
FS:  00007f2078daf700(0000) GS:ffff8881dae00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff8881d9bfcf88 CR3: 00000001c3e0c000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 __warn.cold.8+0x20/0x45 kernel/panic.c:540
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 report_bug+0x254/0x2d0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:290
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:969
RIP: 0010:debug_print_object+0x16a/0x210 lib/debugobjects.c:326
Code: 60 88 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 92 00 00 00 48 8b 14 dd 20 da 60 88 4c 89 fe 48 c7 c7 c0 cf 60 88 e8 76 42 b5 fd <0f> 0b 83 05 f1 75 81 06 01 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffff8881daf07a40 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000000000
RDX: 0000000000010000 RSI: ffffffff8165e7e5 RDI: 0000000000000005
RBP: ffff8881daf07a80 R08: ffff8881d95ea600 R09: ffffed103b5e3ef8
R10: ffffed103b5e3ef8 R11: ffff8881daf1f7c7 R12: 0000000000000001
R13: ffffffff895a9020 R14: ffffffff816d6760 R15: ffffffff8860d3a0
 debug_object_deactivate+0x2c7/0x450 lib/debugobjects.c:566
 debug_hrtimer_deactivate kernel/time/hrtimer.c:421 [inline]
 debug_deactivate kernel/time/hrtimer.c:471 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1368 [inline]
 __hrtimer_run_queues+0x2b6/0x10d0 kernel/time/hrtimer.c:1460
 hrtimer_interrupt+0x313/0x780 kernel/time/hrtimer.c:1518
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1034 [inline]
 smp_apic_timer_interrupt+0x1a1/0x760 arch/x86/kernel/apic/apic.c:1059
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:804
 </IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:761 [inline]
RIP: 0010:lock_release+0x51d/0xa00 kernel/locking/lockdep.c:3866
Code: 00 00 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 55 03 00 00 48 83 3d d2 29 f0 07 00 0f 84 15 02 00 00 48 8b bd e0 fe ff ff 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 01 c3 48 c7 03 00
RSP: 0018:ffff8881d95ff1e0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: 1ffff1103b2bfe41 RCX: 1ffff1103b2bd5ce
RDX: 1ffffffff12a3f6e RSI: 1ffff1103b2bd5df RDI: 0000000000000286
RBP: ffff8881d95ff310 R08: 1ffff1103b2bfe45 R09: ffffed103b5e5b67
R10: 0000000000000004 R11: ffff8881daf2db3b R12: ffff8881d95ea600
R13: 0000000000000003 R14: ffff8881d95ea600 R15: ffff8881d95ff228
 rcu_lock_release include/linux/rcupdate.h:228 [inline]
 rcu_read_unlock include/linux/rcupdate.h:661 [inline]
 inet_twsk_purge+0x5e1/0x870 net/ipv4/inet_timewait_sock.c:298
 dccp_v4_exit_batch+0x1a/0x20 net/dccp/ipv4.c:1033
 ops_exit_list.isra.5+0x105/0x160 net/core/net_namespace.c:156
 cleanup_net+0x555/0xb10 net/core/net_namespace.c:551
 process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153
 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296
 kthread+0x35a/0x440 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

======================================================
WARNING: possible circular locking dependency detected
4.20.0-rc2+ #294 Not tainted
------------------------------------------------------
kworker/u4:2/51 is trying to acquire lock:
0000000091c62f63 ((console_sem).lock){-.-.}, at: down_trylock+0x13/0x70 kernel/locking/semaphore.c:136

but task is already holding lock:
000000002e556cbd (&obj_hash[i].lock){-.-.}, at: debug_object_deactivate+0xf7/0x450 lib/debugobjects.c:541

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+0x99/0xd0 kernel/locking/spinlock.c:152
       __debug_object_init+0x127/0x1290 lib/debugobjects.c:384
       debug_object_init+0x16/0x20 lib/debugobjects.c:432
       debug_hrtimer_init kernel/time/hrtimer.c:410 [inline]
       debug_init kernel/time/hrtimer.c:458 [inline]
       hrtimer_init+0x97/0x490 kernel/time/hrtimer.c:1308
       init_dl_task_timer+0x1b/0x50 kernel/sched/deadline.c:1057
       __sched_fork+0x2ae/0x590 kernel/sched/core.c:2166
       init_idle+0x75/0x740 kernel/sched/core.c:5374
       sched_init+0xb33/0xc07 kernel/sched/core.c:6060
       start_kernel+0x4be/0xa2b init/main.c:608
       x86_64_start_reservations+0x2e/0x30 arch/x86/kernel/head64.c:472
       x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:451
       secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243

-> #2 (&rq->lock){-.-.}:
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:144
       rq_lock kernel/sched/sched.h:1126 [inline]
       task_fork_fair+0xb0/0x6d0 kernel/sched/fair.c:9768
       sched_fork+0x443/0xba0 kernel/sched/core.c:2359
       copy_process+0x25b8/0x87a0 kernel/fork.c:1887
       _do_fork+0x1cb/0x11d0 kernel/fork.c:2216
       kernel_thread+0x34/0x40 kernel/fork.c:2275
       rest_init+0x28/0x372 init/main.c:409
       arch_call_rest_init+0xe/0x1b
       start_kernel+0x9f0/0xa2b init/main.c:745
       x86_64_start_reservations+0x2e/0x30 arch/x86/kernel/head64.c:472
       x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:451
       secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243

-> #1 (&p->pi_lock){-.-.}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x99/0xd0 kernel/locking/spinlock.c:152
       try_to_wake_up+0xdc/0x1490 kernel/sched/core.c:1965
       wake_up_process+0x10/0x20 kernel/sched/core.c:2129
       __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:236
       console_unlock+0x811/0x1190 kernel/printk/printk.c:2432
       vprintk_emit+0x391/0x990 kernel/printk/printk.c:1922
       vprintk_default+0x28/0x30 kernel/printk/printk.c:1964
       vprintk_func+0x7e/0x181 kernel/printk/printk_safe.c:398
       printk+0xa7/0xcf kernel/printk/printk.c:1997
       check_stack_usage kernel/exit.c:755 [inline]
       do_exit.cold.18+0x57/0x16f kernel/exit.c:916
       do_group_exit+0x177/0x440 kernel/exit.c:970
       __do_sys_exit_group kernel/exit.c:981 [inline]
       __se_sys_exit_group kernel/exit.c:979 [inline]
       __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:979
       do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #0 ((console_sem).lock){-.-.}:
       lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x99/0xd0 kernel/locking/spinlock.c:152
       down_trylock+0x13/0x70 kernel/locking/semaphore.c:136
       __down_trylock_console_sem+0xae/0x1f0 kernel/printk/printk.c:219
       console_trylock+0x15/0xa0 kernel/printk/printk.c:2247
       console_trylock_spinning kernel/printk/printk.c:1653 [inline]
       vprintk_emit+0x372/0x990 kernel/printk/printk.c:1921
       vprintk_default+0x28/0x30 kernel/printk/printk.c:1964
       vprintk_func+0x7e/0x181 kernel/printk/printk_safe.c:398
       printk+0xa7/0xcf kernel/printk/printk.c:1997
       __warn_printk+0x8c/0xe0 kernel/panic.c:594
       debug_print_object+0x16a/0x210 lib/debugobjects.c:326
       debug_object_deactivate+0x2c7/0x450 lib/debugobjects.c:566
       debug_hrtimer_deactivate kernel/time/hrtimer.c:421 [inline]
       debug_deactivate kernel/time/hrtimer.c:471 [inline]
       __run_hrtimer kernel/time/hrtimer.c:1368 [inline]
       __hrtimer_run_queues+0x2b6/0x10d0 kernel/time/hrtimer.c:1460
       hrtimer_interrupt+0x313/0x780 kernel/time/hrtimer.c:1518
       local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1034 [inline]
       smp_apic_timer_interrupt+0x1a1/0x760 arch/x86/kernel/apic/apic.c:1059
       apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:804
       arch_local_irq_restore arch/x86/include/asm/paravirt.h:761 [inline]
       lock_release+0x51d/0xa00 kernel/locking/lockdep.c:3866
       rcu_lock_release include/linux/rcupdate.h:228 [inline]
       rcu_read_unlock include/linux/rcupdate.h:661 [inline]
       inet_twsk_purge+0x5e1/0x870 net/ipv4/inet_timewait_sock.c:298
       dccp_v4_exit_batch+0x1a/0x20 net/dccp/ipv4.c:1033
       ops_exit_list.isra.5+0x105/0x160 net/core/net_namespace.c:156
       cleanup_net+0x555/0xb10 net/core/net_namespace.c:551
       process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153
       worker_thread+0x17f/0x1390 kernel/workqueue.c:2296
       kthread+0x35a/0x440 kernel/kthread.c:246
       ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

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 ***

5 locks held by kworker/u4:2/51:
 #0: 00000000a68b27d9 ((wq_completion)"%s""netns"){+.+.}, at: __write_once_size include/linux/compiler.h:209 [inline]
 #0: 00000000a68b27d9 ((wq_completion)"%s""netns"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: 00000000a68b27d9 ((wq_completion)"%s""netns"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline]
 #0: 00000000a68b27d9 ((wq_completion)"%s""netns"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline]
 #0: 00000000a68b27d9 ((wq_completion)"%s""netns"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline]
 #0: 00000000a68b27d9 ((wq_completion)"%s""netns"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0: 00000000a68b27d9 ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124
 #1: 00000000e1ea6a3b (net_cleanup_work){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128
 #2: 00000000b34795ad (pernet_ops_rwsem){++++}, at: cleanup_net+0x13f/0xb10 net/core/net_namespace.c:518
 #3: 000000007c641a5b (hrtimer_bases.lock){-.-.}, at: hrtimer_interrupt+0xfc/0x780 kernel/time/hrtimer.c:1499
 #4: 000000002e556cbd (&obj_hash[i].lock){-.-.}, at: debug_object_deactivate+0xf7/0x450 lib/debugobjects.c:541

stack backtrace:
CPU: 1 PID: 51 Comm: kworker/u4:2 Not tainted 4.20.0-rc2+ #294
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x244/0x39d lib/dump_stack.c:113
 print_circular_bug.isra.35.cold.54+0x1bd/0x27d kernel/locking/lockdep.c:1221
 check_prev_add kernel/locking/lockdep.c:1863 [inline]
 check_prevs_add kernel/locking/lockdep.c:1976 [inline]
 validate_chain kernel/locking/lockdep.c:2347 [inline]
 __lock_acquire+0x3399/0x4c20 kernel/locking/lockdep.c:3341
 lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x99/0xd0 kernel/locking/spinlock.c:152
 down_trylock+0x13/0x70 kernel/locking/semaphore.c:136
 __down_trylock_console_sem+0xae/0x1f0 kernel/printk/printk.c:219
 console_trylock+0x15/0xa0 kernel/printk/printk.c:2247
 console_trylock_spinning kernel/printk/printk.c:1653 [inline]
 vprintk_emit+0x372/0x990 kernel/printk/printk.c:1921
 vprintk_default+0x28/0x30 kernel/printk/printk.c:1964
 vprintk_func+0x7e/0x181 kernel/printk/printk_safe.c:398
 printk+0xa7/0xcf kernel/printk/printk.c:1997
 __warn_printk+0x8c/0xe0 kernel/panic.c:594
 debug_print_object+0x16a/0x210 lib/debugobjects.c:326
 debug_object_deactivate+0x2c7/0x450 lib/debugobjects.c:566
 debug_hrtimer_deactivate kernel/time/hrtimer.c:421 [inline]
 debug_deactivate kernel/time/hrtimer.c:471 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1368 [inline]
 __hrtimer_run_queues+0x2b6/0x10d0 kernel/time/hrtimer.c:1460
 hrtimer_interrupt+0x313/0x780 kernel/time/hrtimer.c:1518
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1034 [inline]
 smp_apic_timer_interrupt+0x1a1/0x760 arch/x86/kernel/apic/apic.c:1059
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:804
 </IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:761 [inline]
RIP: 0010:lock_release+0x51d/0xa00 kernel/locking/lockdep.c:3866
Code: 00 00 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 55 03 00 00 48 83 3d d2 29 f0 07 00 0f 84 15 02 00 00 48 8b bd e0 fe ff ff 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 01 c3 48 c7 03 00
RSP: 0018:ffff8881d95ff1e0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: 1ffff1103b2bfe41 RCX: 1ffff1103b2bd5ce
RDX: 1ffffffff12a3f6e RSI: 1ffff1103b2bd5df RDI: 0000000000000286
RBP: ffff8881d95ff310 R08: 1ffff1103b2bfe45 R09: ffffed103b5e5b67
R10: 0000000000000004 R11: ffff8881daf2db3b R12: ffff8881d95ea600
R13: 0000000000000003 R14: ffff8881d95ea600 R15: ffff8881d95ff228
 rcu_lock_release include/linux/rcupdate.h:228 [inline]
 rcu_read_unlock include/linux/rcupdate.h:661 [inline]
 inet_twsk_purge+0x5e1/0x870 net/ipv4/inet_timewait_sock.c:298
 dccp_v4_exit_batch+0x1a/0x20 net/dccp/ipv4.c:1033
 ops_exit_list.isra.5+0x105/0x160 net/core/net_namespace.c:156
 cleanup_net+0x555/0xb10 net/core/net_namespace.c:551
 ? find_held_l
Lost 47 message(s)!
Shutting down cpus with NMI
Kernel Offset: disabled
Rebooting in 86400 seconds..