IPVS: ftp: loaded support on port[0] = 21
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 4412 Comm: syzkaller402313 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:timerqueue_add+0xb8/0x280 lib/timerqueue.c:52
RSP: 0018:ffff8801db307a28 EFLAGS: 00010002
RAX: ffffed003b664cc7 RBX: ffff8801db326620 RCX: ffffffff866a78ec
RDX: 0000502020005023 RSI: ffff8801db326620 RDI: 0002810100028119
RBP: ffff8801db307a68 R08: 0000000000000000 R09: 1ffff1003b660f0f
R10: ffff8801db307a78 R11: 0000000000000002 R12: dffffc0000000000
R13: 0002810100028101 R14: 00000006ad949680 R15: ffff8801b7b97cc8
FS:  000000000147e880(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000421d60 CR3: 00000001b47c2005 CR4: 00000000001606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 enqueue_hrtimer+0x177/0x4b0 kernel/time/hrtimer.c:944
 __run_hrtimer kernel/time/hrtimer.c:1364 [inline]
 __hrtimer_run_queues+0xb15/0xec0 kernel/time/hrtimer.c:1411
 hrtimer_interrupt+0x2a5/0x6f0 kernel/time/hrtimer.c:1469
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
 smp_apic_timer_interrupt+0x14a/0x700 arch/x86/kernel/apic/apic.c:1050
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:857
 </IRQ>
RIP: 0010:__memmove+0x24/0x1a0 arch/x86/lib/memmove_64.S:43
RSP: 0018:ffff8801b467ee28 EFLAGS: 00010287 ORIG_RAX: ffffffffffffff12
RAX: ffff8801b52ec984 RBX: fffffffffffffffe RCX: fffffffffd610431
RDX: fffffffffffffffe RSI: ffff8801b7cdc54d RDI: ffff8801b7cdc551
RBP: ffff8801b467ee48 R08: ffff8801b52ec97e R09: ffffed0036a5d931
R10: 0000000000000001 R11: ffffed0036a5d930 R12: ffff8801b52ec984
R13: ffff8801b52ec980 R14: ffff8801b4108106 R15: ffff8801b4108040
 memmove include/linux/string.h:360 [inline]
 skb_reorder_vlan_header net/core/skbuff.c:5031 [inline]
 skb_vlan_untag+0x470/0xc40 net/core/skbuff.c:5061
 __netif_receive_skb_core+0x119c/0x3460 net/core/dev.c:4460
 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4627
 netif_receive_skb_internal+0x10b/0x670 net/core/dev.c:4701
 netif_receive_skb+0xae/0x390 net/core/dev.c:4725
 tun_rx_batched.isra.50+0x5ee/0x870 drivers/net/tun.c:1555
 tun_get_user+0x299e/0x3c20 drivers/net/tun.c:1962
 tun_chr_write_iter+0xb9/0x160 drivers/net/tun.c:1990
 call_write_iter include/linux/fs.h:1782 [inline]
 new_sync_write fs/read_write.c:469 [inline]
 __vfs_write+0x684/0x970 fs/read_write.c:482
 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
RIP: 0033:0x4447d9
RSP: 002b:00007ffe5ab19af8 EFLAGS: 00000297 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004447d9
RDX: 0000000000000157 RSI: 0000000020000180 RDI: 0000000000000004
RBP: 0000000030626669 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000400 R11: 0000000000000297 R12: 00000000004020e0
R13: 0000000000402170 R14: 0000000000000000 R15: 0000000000000000
Code: 00 00 4d 8b 2f 4d 85 ed 74 3d e8 34 50 07 fb 48 8b 45 d0 80 38 00 0f 85 be 01 00 00 49 8d 7d 18 4c 8b 73 18 48 89 fa 48 c1 ea 03 <42> 80 3c 22 00 0f 85 9a 01 00 00 4d 3b 75 18 7c a3 e8 02 50 07 
RIP: timerqueue_add+0xb8/0x280 lib/timerqueue.c:52 RSP: ffff8801db307a28

======================================================
WARNING: possible circular locking dependency detected
4.16.0-rc7+ #3 Not tainted
------------------------------------------------------
syzkaller402313/4412 is trying to acquire lock:
 ((console_sem).lock){-.-.}, at: [<00000000af0b4a23>] down_trylock+0x13/0x70 kernel/locking/semaphore.c:136

but task is already holding lock:
 (hrtimer_bases.lock){-.-.}, at: [<00000000bf18422f>] __run_hrtimer kernel/time/hrtimer.c:1351 [inline]
 (hrtimer_bases.lock){-.-.}, at: [<00000000bf18422f>] __hrtimer_run_queues+0x3dc/0xec0 kernel/time/hrtimer.c:1411

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+0x96/0xc0 kernel/locking/spinlock.c:152
       lock_hrtimer_base.isra.16+0x75/0x130 kernel/time/hrtimer.c:174
       hrtimer_start_range_ns+0x106/0xb80 kernel/time/hrtimer.c:1097
       hrtimer_start_expires include/linux/hrtimer.h:412 [inline]
       start_rt_bandwidth kernel/sched/rt.c:72 [inline]
       inc_rt_group kernel/sched/rt.c:1140 [inline]
       inc_rt_tasks kernel/sched/rt.c:1184 [inline]
       __enqueue_rt_entity kernel/sched/rt.c:1254 [inline]
       enqueue_rt_entity kernel/sched/rt.c:1298 [inline]
       enqueue_task_rt+0x94f/0xfb0 kernel/sched/rt.c:1328
       enqueue_task kernel/sched/core.c:772 [inline]
       __sched_setscheduler+0xfef/0x2300 kernel/sched/core.c:4302
       _sched_setscheduler+0x20d/0x350 kernel/sched/core.c:4339
       sched_setscheduler+0xe/0x10 kernel/sched/core.c:4354
       watchdog_set_prio kernel/watchdog.c:455 [inline]
       watchdog_enable+0x122/0x170 kernel/watchdog.c:477
       smpboot_thread_fn+0x359/0x7c0 kernel/smpboot.c:145
       kthread+0x33c/0x400 kernel/kthread.c:238
       ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406

-> #3 (&rt_b->rt_runtime_lock){-...}:
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144
       start_rt_bandwidth kernel/sched/rt.c:60 [inline]
       inc_rt_group kernel/sched/rt.c:1140 [inline]
       inc_rt_tasks kernel/sched/rt.c:1184 [inline]
       __enqueue_rt_entity kernel/sched/rt.c:1254 [inline]
       enqueue_rt_entity kernel/sched/rt.c:1298 [inline]
       enqueue_task_rt+0x62a/0xfb0 kernel/sched/rt.c:1328
       enqueue_task kernel/sched/core.c:772 [inline]
       __sched_setscheduler+0xfef/0x2300 kernel/sched/core.c:4302
       _sched_setscheduler+0x20d/0x350 kernel/sched/core.c:4339
       sched_setscheduler+0xe/0x10 kernel/sched/core.c:4354
       watchdog_set_prio kernel/watchdog.c:455 [inline]
       watchdog_enable+0x122/0x170 kernel/watchdog.c:477
       smpboot_thread_fn+0x359/0x7c0 kernel/smpboot.c:145
       kthread+0x33c/0x400 kernel/kthread.c:238
       ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406

-> #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
       vprintk_emit+0x5c3/0xb90 kernel/printk/printk.c:1907
       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
       regdb_fw_cb+0x1d7/0x220 net/wireless/reg.c:886
       request_firmware_work_func+0x151/0x2c0 drivers/base/firmware_class.c:1442
       process_one_work+0xc47/0x1bb0 kernel/workqueue.c:2113
       worker_thread+0x223/0x1990 kernel/workqueue.c:2247
       kthread+0x33c/0x400 kernel/kthread.c:238
       ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406

-> #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
       kasan_die_handler+0x31/0x3f arch/x86/mm/kasan_init_64.c:247
       notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93
       __atomic_notifier_call_chain kernel/notifier.c:183 [inline]
       atomic_notifier_call_chain+0x77/0x140 kernel/notifier.c:193
       notify_die+0x18c/0x280 kernel/notifier.c:549
       do_general_protection+0x331/0x3e0 arch/x86/kernel/traps.c:558
       general_protection+0x25/0x50 arch/x86/entry/entry_64.S:1150
       timerqueue_add+0xb8/0x280 lib/timerqueue.c:52
       enqueue_hrtimer+0x177/0x4b0 kernel/time/hrtimer.c:944
       __run_hrtimer kernel/time/hrtimer.c:1364 [inline]
       __hrtimer_run_queues+0xb15/0xec0 kernel/time/hrtimer.c:1411
       hrtimer_interrupt+0x2a5/0x6f0 kernel/time/hrtimer.c:1469
       local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
       smp_apic_timer_interrupt+0x14a/0x700 arch/x86/kernel/apic/apic.c:1050
       apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:857
       __memmove+0x24/0x1a0 arch/x86/lib/memmove_64.S:43
       memmove include/linux/string.h:360 [inline]
       skb_reorder_vlan_header net/core/skbuff.c:5031 [inline]
       skb_vlan_untag+0x470/0xc40 net/core/skbuff.c:5061
       __netif_receive_skb_core+0x119c/0x3460 net/core/dev.c:4460
       __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4627
       netif_receive_skb_internal+0x10b/0x670 net/core/dev.c:4701
       netif_receive_skb+0xae/0x390 net/core/dev.c:4725
       tun_rx_batched.isra.50+0x5ee/0x870 drivers/net/tun.c:1555
       tun_get_user+0x299e/0x3c20 drivers/net/tun.c:1962
       tun_chr_write_iter+0xb9/0x160 drivers/net/tun.c:1990
       call_write_iter include/linux/fs.h:1782 [inline]
       new_sync_write fs/read_write.c:469 [inline]
       __vfs_write+0x684/0x970 fs/read_write.c:482
       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

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 ***

3 locks held by syzkaller402313/4412:
 #0:  (rcu_read_lock){....}, at: [<00000000a5bed563>] arch_static_branch arch/x86/include/asm/jump_label.h:36 [inline]
 #0:  (rcu_read_lock){....}, at: [<00000000a5bed563>] static_key_false include/linux/jump_label.h:142 [inline]
 #0:  (rcu_read_lock){....}, at: [<00000000a5bed563>] netif_receive_skb_internal+0xa2/0x670 net/core/dev.c:4675
 #1:  (hrtimer_bases.lock){-.-.}, at: [<00000000bf18422f>] __run_hrtimer kernel/time/hrtimer.c:1351 [inline]
 #1:  (hrtimer_bases.lock){-.-.}, at: [<00000000bf18422f>] __hrtimer_run_queues+0x3dc/0xec0 kernel/time/hrtimer.c:1411
 #2:  (rcu_read_lock){....}, at: [<00000000a372e3c7>] rcu_read_unlock include/linux/rcupdate.h:682 [inline]
 #2:  (rcu_read_lock){....}, at: [<00000000a372e3c7>] atomic_notifier_call_chain+0x0/0x140 kernel/notifier.c:184

stack backtrace:
CPU: 1 PID: 4412 Comm: syzkaller402313 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __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
 kasan_die_handler+0x31/0x3f arch/x86/mm/kasan_init_64.c:247
 notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93
 __atomic_notifier_call_chain kernel/notifier.c:183 [inline]
 atomic_notifier_call_chain+0x77/0x140 kernel/notifier.c:193
 notify_die+0x18c/0x280 kernel/notifier.c:549
 do_general_protection+0x331/0x3e0 arch/x86/kernel/traps.c:558
 general_protection+0x25/0x50 arch/x86/entry/entry_64.S:1150
RIP: 0010:timerqueue_add+0xb8/0x280 lib/timerqueue.c:52
RSP: 0018:ffff8801db307a28 EFLAGS: 00010002
RAX: ffffed003b664cc7 RBX: ffff8801db326620 RCX: ffffffff866a78ec
RDX: 0000502020005023 RSI: ffff8801db326620 RDI: 0002810100028119
RBP: ffff8801db307a68 R08: 0000000000000000 R09: 1ffff1003b660f0f
R10: ffff8801db307a78 R11: 0000000000000002 R12: dffffc0000000000
R13: 0002810100028101 R14: 00000006ad949680 R15: ffff8801b7b97cc8
 enqueue_hrtimer+0x177/0x4b0 kernel/time/hrtimer.c:944
 __run_hrtimer kernel/time/hrtimer.c:1364 [inline]
 __hrtimer_run_queues+0xb15/0xec0 kernel/time/hrtimer.c:1411
 hrtimer_interrupt+0x2a5/0x6f0 kernel/time/hrtimer.c:1469
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
 smp_apic_timer_interrupt+0x14a/0x700 arch/x86/kernel/apic/apic.c:1050
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:857
 </IRQ>
RIP: 0010:__memmove+0x24/0x1a0 arch/x86/lib/memmove_64.S:43
RSP: 0018:ffff8801b467ee28 EFLAGS: 00010287 ORIG_RAX: ffffffffffffff12
RAX: ffff8801b52ec984 RBX: fffffffffffffffe RCX: fffffffffd610431
RDX: fffffffffffffffe RSI: ffff8801b7cdc54d RDI: ffff8801b7cdc551
Lost 83 message(s)!
---[ end trace cad7214be10b65c1 ]---