kasan: CONFIG_KASAN_INLINE enabled
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 3 Comm:  Not tainted 4.20.0+ #9
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__read_once_size include/linux/compiler.h:191 [inline]
RIP: 0010:get_running_cputimer include/linux/sched/cputime.h:85 [inline]
RIP: 0010:account_group_system_time include/linux/sched/cputime.h:149 [inline]
RIP: 0010:account_system_index_time+0xe8/0x5f0 kernel/sched/cputime.c:168
Code: 04 00 00 49 8b 84 24 00 07 00 00 48 ba 00 00 00 00 00 fc ff df 48 8d b8 40 01 00 00 48 8d 88 28 01 00 00 48 89 fe 48 c1 ee 03 <0f> b6 14 16 48 89 fe 83 e6 07 40 38 f2 7f 08 84 d2 0f 85 93 03 00
RSP: 0018:ffff8880ae707a80 EFLAGS: 00010006
RAX: 0000000041b58ab3 RBX: 1ffff11015ce0f54 RCX: 0000000041b58bdb
RDX: dffffc0000000000 RSI: 000000000836b17e RDI: 0000000041b58bf3
RBP: ffff8880ae707b48 R08: ffff8880ae71f5f0 R09: fffffbfff13363dd
R10: fffffbfff1301b45 R11: ffffffff899b1ee3 R12: ffff8880a94bc440
R13: 0000000000306fb8 R14: 0000000000000003 R15: ffff8880ae707b20
FS:  0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e830000 CR3: 0000000076895000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 irqtime_account_process_tick.isra.0+0x3a2/0x490 kernel/sched/cputime.c:380
 account_process_tick+0x27f/0x350 kernel/sched/cputime.c:483
 update_process_times+0x25/0x80 kernel/time/timer.c:1633
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161
 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271
 __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
 __hrtimer_run_queues+0x3a7/0x1050 kernel/time/hrtimer.c:1451
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline]
 smp_apic_timer_interrupt+0x18d/0x760 arch/x86/kernel/apic/apic.c:1060
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
 </IRQ>
Modules linked in:

======================================================
WARNING: possible circular locking dependency detected
4.20.0+ #9 Not tainted
------------------------------------------------------
syz-executor0/7584 is trying to acquire lock:
00000000b4c855b6 ((console_sem).lock){-.-.}, at: down_trylock+0x13/0x70 kernel/locking/semaphore.c:136

but task is already holding lock:
00000000e775e80e (hrtimer_bases.lock){-.-.}, at: hrtimer_interrupt+0xff/0x770 kernel/time/hrtimer.c:1490

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (hrtimer_bases.lock){-.-.}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152
       lock_hrtimer_base.isra.0+0x75/0x130 kernel/time/hrtimer.c:165
       hrtimer_start_range_ns+0x120/0xda0 kernel/time/hrtimer.c:1104
       hrtimer_start_expires include/linux/hrtimer.h:409 [inline]
       start_rt_bandwidth kernel/sched/rt.c:70 [inline]
       inc_rt_group kernel/sched/rt.c:1147 [inline]
       inc_rt_tasks kernel/sched/rt.c:1191 [inline]
       __enqueue_rt_entity kernel/sched/rt.c:1261 [inline]
       enqueue_rt_entity kernel/sched/rt.c:1305 [inline]
       enqueue_task_rt+0x95b/0x1010 kernel/sched/rt.c:1335
       enqueue_task+0xb9/0x380 kernel/sched/core.c:730
       __sched_setscheduler+0xe32/0x1fe0 kernel/sched/core.c:4336
       _sched_setscheduler+0x218/0x340 kernel/sched/core.c:4373
       sched_setscheduler+0xe/0x10 kernel/sched/core.c:4388
       watchdog_dev_init+0x109/0x1db drivers/watchdog/watchdog_dev.c:1144
       watchdog_init+0x81/0x294 drivers/watchdog/watchdog_core.c:355
       do_one_initcall+0x129/0x937 init/main.c:889
       do_initcall_level init/main.c:957 [inline]
       do_initcalls init/main.c:965 [inline]
       do_basic_setup init/main.c:983 [inline]
       kernel_init_freeable+0x4db/0x5ca init/main.c:1136
       kernel_init+0x12/0x1c5 init/main.c:1056
       ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

-> #3 (&rt_b->rt_runtime_lock){-...}:
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
       __enable_runtime kernel/sched/rt.c:786 [inline]
       rq_online_rt+0xb4/0x390 kernel/sched/rt.c:2178
       set_rq_online.part.0+0xe7/0x140 kernel/sched/core.c:5666
       set_rq_online kernel/sched/core.c:5772 [inline]
       sched_cpu_activate+0x29e/0x430 kernel/sched/core.c:5765
       cpuhp_invoke_callback+0x2f6/0x2110 kernel/cpu.c:168
       cpuhp_thread_fun+0x496/0x8a0 kernel/cpu.c:685
       smpboot_thread_fn+0x6ab/0xa10 kernel/smpboot.c:164
       kthread+0x357/0x430 kernel/kthread.c:246
       ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

-> #2 (&rq->lock){-.-.}:
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
       rq_lock kernel/sched/sched.h:1149 [inline]
       task_fork_fair+0xb5/0x7a0 kernel/sched/fair.c:10058
       sched_fork+0x437/0xb90 kernel/sched/core.c:2359
       copy_process+0x1ff6/0x8730 kernel/fork.c:1893
       _do_fork+0x1a9/0x1170 kernel/fork.c:2222
       kernel_thread+0x34/0x40 kernel/fork.c:2281
       rest_init+0x28/0x37b init/main.c:409
       arch_call_rest_init+0xe/0x1b
       start_kernel+0x882/0x8bd init/main.c:741
       x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:470
       x86_64_start_kernel+0x77/0x7b 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+0x95/0xcd kernel/locking/spinlock.c:152
       try_to_wake_up+0xb9/0x1480 kernel/sched/core.c:1965
       wake_up_process+0x10/0x20 kernel/sched/core.c:2129
       __up.isra.0+0x1c0/0x2a0 kernel/locking/semaphore.c:262
       up+0x13e/0x1c0 kernel/locking/semaphore.c:187
       __up_console_sem+0xb7/0x1c0 kernel/printk/printk.c:236
       console_unlock+0x778/0x11e0 kernel/printk/printk.c:2426
       vprintk_emit+0x370/0x960 kernel/printk/printk.c:1931
       vprintk_default+0x28/0x30 kernel/printk/printk.c:1958
       vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398
       printk+0xba/0xed kernel/printk/printk.c:1991
       check_stack_usage kernel/exit.c:755 [inline]
       do_exit.cold+0x57/0x16a kernel/exit.c:916
       do_group_exit+0x177/0x430 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+0x44/0x50 kernel/exit.c:979
       do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #0 ((console_sem).lock){-.-.}:
       lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3841
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152
       down_trylock+0x13/0x70 kernel/locking/semaphore.c:136
       __down_trylock_console_sem+0xa8/0x210 kernel/printk/printk.c:219
       console_trylock+0x15/0xa0 kernel/printk/printk.c:2242
       console_trylock_spinning kernel/printk/printk.c:1662 [inline]
       vprintk_emit+0x351/0x960 kernel/printk/printk.c:1930
       vprintk_default+0x28/0x30 kernel/printk/printk.c:1958
       vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398
       printk+0xba/0xed kernel/printk/printk.c:1991
       kasan_die_handler arch/x86/mm/kasan_init_64.c:252 [inline]
       kasan_die_handler.cold+0x11/0x23 arch/x86/mm/kasan_init_64.c:247
       notifier_call_chain+0x179/0x380 kernel/notifier.c:93
       __atomic_notifier_call_chain kernel/notifier.c:183 [inline]
       atomic_notifier_call_chain+0x96/0x190 kernel/notifier.c:193
       notify_die+0x1b2/0x270 kernel/notifier.c:549
       do_general_protection+0x13d/0x300 arch/x86/kernel/traps.c:557
       general_protection+0x1e/0x30 arch/x86/entry/entry_64.S:1142
       ____rb_erase_color lib/rbtree.c:370 [inline]
       rb_erase+0x60b/0x3550 lib/rbtree.c:462
       timerqueue_del+0x86/0x150 lib/timerqueue.c:87
       __remove_hrtimer+0xa8/0x1c0 kernel/time/hrtimer.c:975
       __run_hrtimer kernel/time/hrtimer.c:1371 [inline]
       __hrtimer_run_queues+0x311/0x1050 kernel/time/hrtimer.c:1451
       hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509
       local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline]
       smp_apic_timer_interrupt+0x18d/0x760 arch/x86/kernel/apic/apic.c:1060
       apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
       preempt_count_sub+0x57/0x160 kernel/sched/core.c:3222
       rcu_lockdep_current_cpu_online kernel/rcu/tree.c:984 [inline]
       rcu_lockdep_current_cpu_online+0x1aa/0x220 kernel/rcu/tree.c:971
       rcu_read_lock_sched_held+0x97/0x130 kernel/rcu/update.c:114
       trace_sched_process_wait include/trace/events/sched.h:263 [inline]
       do_wait+0x9c7/0xb90 kernel/exit.c:1495
       kernel_wait4+0x254/0x440 kernel/exit.c:1659
       __do_sys_wait4+0x147/0x160 kernel/exit.c:1671
       __se_sys_wait4 kernel/exit.c:1667 [inline]
       __x64_sys_wait4+0x97/0xf0 kernel/exit.c:1667
       do_syscall_64+0x1a3/0x800 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 --> &rt_b->rt_runtime_lock --> hrtimer_bases.lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(hrtimer_bases.lock);
                               lock(&rt_b->rt_runtime_lock);
                               lock(hrtimer_bases.lock);
  lock((console_sem).lock);

 *** DEADLOCK ***

2 locks held by syz-executor0/7584:
 #0: 00000000e775e80e (hrtimer_bases.lock){-.-.}, at: hrtimer_interrupt+0xff/0x770 kernel/time/hrtimer.c:1490
 #1: 0000000075502bc6 (rcu_read_lock){....}, at: atomic_notifier_call_chain+0x0/0x190 kernel/notifier.c:329

stack backtrace:
CPU: 0 PID: 7584 Comm: syz-executor0 Not tainted 4.20.0+ #9
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1db/0x2d0 lib/dump_stack.c:113
 print_circular_bug.isra.0.cold+0x1cc/0x28f kernel/locking/lockdep.c:1224
 check_prev_add kernel/locking/lockdep.c:1866 [inline]
 check_prevs_add kernel/locking/lockdep.c:1979 [inline]
 validate_chain kernel/locking/lockdep.c:2350 [inline]
 __lock_acquire+0x3014/0x4a30 kernel/locking/lockdep.c:3338
 lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3841
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152
 down_trylock+0x13/0x70 kernel/locking/semaphore.c:136
 __down_trylock_console_sem+0xa8/0x210 kernel/printk/printk.c:219
 console_trylock+0x15/0xa0 kernel/printk/printk.c:2242
 console_trylock_spinning kernel/printk/printk.c:1662 [inline]
 vprintk_emit+0x351/0x960 kernel/printk/printk.c:1930
 vprintk_default+0x28/0x30 kernel/printk/printk.c:1958
 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398
 printk+0xba/0xed kernel/printk/printk.c:1991
 kasan_die_handler arch/x86/mm/kasan_init_64.c:252 [inline]
 kasan_die_handler.cold+0x11/0x23 arch/x86/mm/kasan_init_64.c:247
 notifier_call_chain+0x179/0x380 kernel/notifier.c:93
 __atomic_notifier_call_chain kernel/notifier.c:183 [inline]
 atomic_notifier_call_chain+0x96/0x190 kernel/notifier.c:193
 notify_die+0x1b2/0x270 kernel/notifier.c:549
 do_general_protection+0x13d/0x300 arch/x86/kernel/traps.c:557
 general_protection+0x1e/0x30 arch/x86/entry/entry_64.S:1142
RIP: 0010:____rb_erase_color lib/rbtree.c:370 [inline]
RIP: 0010:rb_erase+0x60b/0x3550 lib/rbtree.c:462
Code: 49 89 c4 e9 c5 fe ff ff 4d 8d 44 24 10 4c 89 c0 48 c1 e8 03 80 3c 18 00 0f 85 2b 21 00 00 4d 8b 74 24 10 4c 89 f0 48 c1 e8 03 <80> 3c 18 00 0f 85 4c 21 00 00 49 8b 06 4d 8d 4e 08 4c 89 c9 48 c1
RSP: 0018:ffff8880ae607698 EFLAGS: 00010002
RAX: 0a213f67ec5a9480 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 1ffff11015cc0edb RSI: ffffed1015cc0f07 RDI: ffff8880a941f468
RBP: ffff8880ae607c00 R08: ffff8880a941f470 R09: ffff8880ae626630
R10: ffffed1015cc5b8f R11: ffff8880ae62dc7b R12: ffff8880a941f460
R13: ffff8880ae625e00 R14: 5109fb3f62d4a400 R15: ffff8880ae607bd8
 timerqueue_del+0x86/0x150 lib/timerqueue.c:87
 __remove_hrtimer+0xa8/0x1c0 kernel/time/hrtimer.c:975
 __run_hrtimer kernel/time/hrtimer.c:1371 [inline]
 __hrtimer_run_queues+0x311/0x1050 kernel/time/hrtimer.c:1451
Lost 67 message(s)!
---[ end trace 76fe0efbc5f9113b ]---
general protection fault: 0000 [#2] PREEMPT SMP KASAN
CPU: 0 PID: 7584 Comm: syz-executor0 Tainted: G      D           4.20.0+ #9
RIP: 0010:__read_once_size include/linux/compiler.h:191 [inline]
RIP: 0010:get_running_cputimer include/linux/sched/cputime.h:85 [inline]
RIP: 0010:account_group_system_time include/linux/sched/cputime.h:149 [inline]
RIP: 0010:account_system_index_time+0xe8/0x5f0 kernel/sched/cputime.c:168
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Code: 04 00 00 49 8b 84 24 00 07 00 00 48 ba 00 00 00 00 00 fc ff df 48 8d b8 40 01 00 00 48 8d 88 28 01 00 00 48 89 fe 48 c1 ee 03 <0f> b6 14 16 48 89 fe 83 e6 07 40 38 f2 7f 08 84 d2 0f 85 93 03 00
RIP: 0010:____rb_erase_color lib/rbtree.c:370 [inline]
RIP: 0010:rb_erase+0x60b/0x3550 lib/rbtree.c:462
RSP: 0018:ffff8880ae707a80 EFLAGS: 00010006
Code: 49 89 c4 e9 c5 fe ff ff 4d 8d 44 24 10 4c 89 c0 48 c1 e8 03 80 3c 18 00 0f 85 2b 21 00 00 4d 8b 74 24 10 4c 89 f0 48 c1 e8 03 <80> 3c 18 00 0f 85 4c 21 00 00 49 8b 06 4d 8d 4e 08 4c 89 c9 48 c1
RAX: 0000000041b58ab3 RBX: 1ffff11015ce0f54 RCX: 0000000041b58bdb
RSP: 0018:ffff8880ae607698 EFLAGS: 00010002
RDX: dffffc0000000000 RSI: 000000000836b17e RDI: 0000000041b58bf3
RAX: 0a213f67ec5a9480 RBX: dffffc0000000000 RCX: 0000000000000000
RBP: ffff8880ae707b48 R08: ffff8880ae71f5f0 R09: fffffbfff13363dd
RDX: 1ffff11015cc0edb RSI: ffffed1015cc0f07 RDI: ffff8880a941f468
R10: fffffbfff1301b45 R11: ffffffff899b1ee3 R12: ffff8880a94bc440
RBP: ffff8880ae607c00 R08: ffff8880a941f470 R09: ffff8880ae626630
R13: 0000000000306fb8 R14: 0000000000000003 R15: ffff8880ae707b20
R10: ffffed1015cc5b8f R11: ffff8880ae62dc7b R12: ffff8880a941f460
FS:  0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
R13: ffff8880ae625e00 R14: 5109fb3f62d4a400 R15: ffff8880ae607bd8
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
FS:  00000000025cd940(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CR2: 0000001b2e830000 CR3: 0000000076895000 CR4: 00000000001406e0
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
CR2: 0000001b2db2d000 CR3: 0000000090045000 CR4: 00000000001406f0
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000