INFO: task syz-executor2:15556 blocked for more than 140 seconds. Not tainted 4.19.0+ #83 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D18552 15556 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3480 schedule+0xfe/0x460 kernel/sched/core.c:3524 __rwsem_down_write_failed_common+0xc9a/0x15e0 kernel/locking/rwsem-xadd.c:577 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:606 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0xa5/0x130 kernel/locking/rwsem.c:72 deactivate_super+0x2b3/0x320 fs/super.c:359 cleanup_mnt+0xbf/0x160 fs/namespace.c:1098 __cleanup_mnt+0x16/0x20 fs/namespace.c:1105 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: 0033:0x459fb7 Code: 02 00 00 ff e0 48 81 f9 80 00 00 00 77 09 48 8d 05 de 02 00 00 ff e0 48 81 f9 00 01 00 00 77 09 48 8d 05 7c 03 00 00 ff e0 48 <81> f9 00 02 00 00 77 09 48 8d 05 1a 04 00 00 ff e0 48 81 f9 00 04 RSP: 002b:00007ffd200caa68 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000459fb7 RDX: 0000000000402e70 RSI: 0000000000000002 RDI: 00007ffd200cab10 RBP: 00000000000004dd R08: 0000000000000000 R09: 000000000000000b R10: 0000000000000005 R11: 0000000000000202 R12: 00007ffd200cbba0 R13: 0000000002172940 R14: 0000000000000000 R15: 0000000000000002 Showing all locks held in the system: 1 lock held by khungtaskd/983: #0: 00000000370331c6 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 1 lock held by rsyslogd/5455: #0: 00000000d801cefe (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5545: #0: 000000003cedd359 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000e856f3ad (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5546: #0: 000000007ecdc8fd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000076d1ca79 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5547: #0: 00000000cf83ffb5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000875b88c0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5548: #0: 000000003f4ec407 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000042358152 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5549: #0: 00000000eea78b97 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000c678100c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5550: #0: 0000000010b810d0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000cb9f6e90 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5551: #0: 000000002067455f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000004edfd6a5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 3 locks held by kworker/u4:7/12257: #0: 000000003d956069 ((wq_completion)"writeback"){+.+.}, at: __write_once_size include/linux/compiler.h:206 [inline] #0: 000000003d956069 ((wq_completion)"writeback"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000003d956069 ((wq_completion)"writeback"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 000000003d956069 ((wq_completion)"writeback"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 000000003d956069 ((wq_completion)"writeback"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 000000003d956069 ((wq_completion)"writeback"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 000000003d956069 ((wq_completion)"writeback"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124 #1: 000000008877e61e ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 #2: 00000000c1f2e0d9 (&type->s_umount_key#79){++++}, at: trylock_super+0x22/0x110 fs/super.c:412 1 lock held by syz-executor2/15556: #0: 00000000c1f2e0d9 (&type->s_umount_key#79){++++}, at: deactivate_super+0x2b3/0x320 fs/super.c:359 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 983 Comm: khungtaskd Not tainted 4.19.0+ #83 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.1+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x1ed 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:144 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0xb3e/0x1050 kernel/hung_task.c:265 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:350 Sending NMI from CPU 1 to CPUs 0: INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.589 msecs NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.19.0+ #83 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:bitmap_and include/linux/bitmap.h:274 [inline] RIP: 0010:cpumask_and include/linux/cpumask.h:405 [inline] RIP: 0010:load_balance+0x436/0x39a0 kernel/sched/fair.c:8649 Code: 48 8b 85 68 fc ff ff 48 c7 c7 90 e9 f2 89 48 89 fa 48 c1 ea 03 48 8b 98 30 01 00 00 48 b8 00 00 00 00 00 fc ff df 80 3c 02 00 <0f> 85 e6 31 00 00 48 8b 95 48 fc ff ff 48 b8 00 00 00 00 00 fc ff RSP: 0018:ffff8801dae071d8 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 0000000000000003 RCX: 0000000000000000 RDX: 1ffffffff13e5d32 RSI: 1ffff1003b5c0e01 RDI: ffffffff89f2e990 RBP: ffff8801dae075d0 R08: ffffffff89276e40 R09: 0000000000000000 R10: 0000000000008624 R11: ffff8801d9a22ad8 R12: ffff8801dae1f610 R13: 0000000000000001 R14: ffff8801dae075a8 R15: ffff8801dae07348 FS: 0000000000000000(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001bc96a000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rebalance_domains+0x845/0xdc0 kernel/sched/fair.c:9075 _nohz_idle_balance+0x621/0x7a0 kernel/sched/fair.c:9461 nohz_idle_balance kernel/sched/fair.c:9509 [inline] run_rebalance_domains+0x2ec/0x500 kernel/sched/fair.c:9692 __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:825 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 f3 03 06 fa 48 8b 45 d8 e9 ca fe ff ff 48 89 df e8 e2 03 06 fa 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:ffffffff89207c10 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff02 RAX: dffffc0000000000 RBX: 1ffffffff1240f86 RCX: 0000000000000000 RDX: 1ffffffff1263f91 RSI: 0000000000000001 RDI: ffffffff8931fc88 RBP: ffffffff89207c10 R08: ffffffff89276e40 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff89207cd0 R13: ffffffff89f2e9a0 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:442 arch_call_rest_init+0xe/0x1b start_kernel+0xa1f/0xa5a init/main.c:744 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