INFO: task syz-executor4:31958 blocked for more than 140 seconds. Not tainted 4.20.0-rc3+ #127 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D23400 31958 28320 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472 schedule+0xfe/0x460 kernel/sched/core.c:3516 exp_funnel_lock kernel/rcu/tree_exp.h:319 [inline] _synchronize_rcu_expedited.constprop.58+0x8df/0x9d0 kernel/rcu/tree_exp.h:620 synchronize_rcu_expedited+0x27/0xa0 kernel/rcu/tree_exp.h:758 synchronize_net+0x3b/0x60 net/core/dev.c:9069 packet_set_ring+0x286/0x1da0 net/packet/af_packet.c:4339 packet_release+0x656/0xda0 net/packet/af_packet.c:2998 __sock_release+0xd7/0x250 net/socket.c:579 sock_close+0x19/0x20 net/socket.c:1141 __fput+0x385/0xa30 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x411021 Code: 83 c4 40 c3 48 8d 05 7b 08 49 00 48 89 04 24 48 c7 44 24 08 0d 00 00 00 e8 ac a8 01 00 0f 0b 48 8d 05 60 08 49 00 48 89 04 24 <48> c7 44 24 08 0d 00 00 00 e8 91 a8 01 00 0f 0b e8 1a 8f 04 00 e9 RSP: 002b:00007ffead1fa960 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000411021 RDX: 0000000000000001 RSI: 0000000000730728 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 00007ffead1fa890 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000001 R14: 00000000000000bb R15: 0000000000000004 Showing all locks held in the system: 1 lock held by khungtaskd/1018: #0: 00000000fb6494ef (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 1 lock held by rsyslogd/5916: #0: 00000000291a054c (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/6007: #0: 00000000c8f353b6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000b3977ade (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6008: #0: 000000008d1f130e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000000cd34adc (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6009: #0: 00000000b1cc6124 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000000f5173b9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6010: #0: 00000000bbff37d8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000000bfca5d8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6011: #0: 000000000796cad2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000084431864 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6012: #0: 00000000579e6286 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000003ef18022 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6013: #0: 0000000070456879 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000093077593 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by syz-executor4/31958: #0: 0000000075070ad9 (&sb->s_type->i_mutex_key#10){+.+.}, at: inode_lock include/linux/fs.h:757 [inline] #0: 0000000075070ad9 (&sb->s_type->i_mutex_key#10){+.+.}, at: __sock_release+0x8b/0x250 net/socket.c:578 #1: 0000000016954c3d (sk_lock-AF_PACKET){+.+.}, at: lock_sock include/net/sock.h:1492 [inline] #1: 0000000016954c3d (sk_lock-AF_PACKET){+.+.}, at: packet_release+0x5ff/0xda0 net/packet/af_packet.c:2995 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1018 Comm: khungtaskd Not tainted 4.20.0-rc3+ #127 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+0x244/0x39d lib/dump_stack.c:113 nmi_cpu_backtrace.cold.2+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1e8/0x22a lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xb51/0x1060 kernel/hung_task.c:289 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.029 msecs NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.20.0-rc3+ #127 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:_nohz_idle_balance+0x56b/0x7a0 kernel/sched/fair.c:9419 Code: 85 28 fe ff ff 48 89 05 43 00 f8 08 48 ba 00 00 00 00 00 fc ff df 48 03 95 f8 fd ff ff 31 c0 b9 06 00 00 00 48 89 d7 f3 48 ab <0f> b6 85 27 fe ff ff 48 8b 75 d0 65 48 33 34 25 28 00 00 00 0f 85 RSP: 0018:ffff8881dae077b8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: ffffed103b5c0f02 RSI: ffff8881dae2ccc0 RDI: ffffed103b5c0f32 RBP: ffff8881dae079d8 R08: 1ffff1103b5c0e9d R09: ffffed103b5c5b67 R10: 0000000000000001 R11: ffff8881dae2db3b R12: 1ffff1103b5c0f42 R13: ffff8881dae07ab0 R14: 0000000000000001 R15: ffff8881dae079b0 FS: 0000000000000000(0000) GS:ffff8881dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001ceb44000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: nohz_idle_balance kernel/sched/fair.c:9543 [inline] run_rebalance_domains+0x2ec/0x500 kernel/sched/fair.c:9726 __do_softirq+0x308/0xb7e kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x17f/0x1c0 kernel/softirq.c:413 scheduler_ipi+0x55a/0xad0 kernel/sched/core.c:1785 smp_reschedule_interrupt+0x109/0x650 arch/x86/kernel/smp.c:278 reschedule_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:828 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57 Code: e9 2c ff ff ff 48 89 c7 48 89 45 d8 e8 33 44 e7 f9 48 8b 45 d8 e9 ca fe ff ff 48 89 df e8 22 44 e7 f9 eb 82 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 90 90 90 90 90 RSP: 0018:ffffffff89407c10 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02 RAX: dffffc0000000000 RBX: 1ffffffff1280f86 RCX: 0000000000000000 RDX: 1ffffffff12a3f71 RSI: 0000000000000001 RDI: ffffffff8951fb88 RBP: ffffffff89407c10 R08: ffffffff89476ec0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff89407cd0 R13: ffffffff8a1632a0 R14: 0000000000000000 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:151 [inline] default_idle+0xbf/0x490 arch/x86/kernel/process.c:498 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:489 default_idle_call+0x6d/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x49b/0x5c0 kernel/sched/idle.c:262 cpu_startup_entry+0x18/0x20 kernel/sched/idle.c:353 rest_init+0x243/0x372 init/main.c:443 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