kworker/dying (21) used greatest stack depth: 12352 bytes left INFO: task syz-executor1:29236 blocked for more than 120 seconds. Not tainted 4.15.0+ #294 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D21008 29236 4167 0x00000004 Call Trace: context_switch kernel/sched/core.c:2845 [inline] __schedule+0x8eb/0x2060 kernel/sched/core.c:3421 schedule+0xf5/0x430 kernel/sched/core.c:3480 io_schedule+0x1c/0x70 kernel/sched/core.c:5096 wait_on_page_bit_common+0x4b3/0x770 mm/filemap.c:1099 wait_on_page_bit mm/filemap.c:1132 [inline] wait_on_page_writeback include/linux/pagemap.h:546 [inline] __filemap_fdatawait_range+0x282/0x430 mm/filemap.c:533 file_write_and_wait_range+0xd7/0x100 mm/filemap.c:756 blkdev_fsync+0x67/0xb0 fs/block_dev.c:623 vfs_fsync_range+0x110/0x260 fs/sync.c:196 generic_write_sync include/linux/fs.h:2679 [inline] blkdev_write_iter+0x2e6/0x3e0 fs/block_dev.c:1895 call_write_iter include/linux/fs.h:1781 [inline] do_iter_readv_writev+0x55c/0x830 fs/read_write.c:653 do_iter_write+0x154/0x540 fs/read_write.c:932 vfs_iter_write+0x77/0xb0 fs/read_write.c:945 iter_file_splice_write+0x7db/0xf30 fs/splice.c:749 do_splice_from fs/splice.c:851 [inline] direct_splice_actor+0x125/0x180 fs/splice.c:1018 splice_direct_to_actor+0x2c1/0x820 fs/splice.c:973 do_splice_direct+0x29b/0x3c0 fs/splice.c:1061 do_sendfile+0x5c9/0xe80 fs/read_write.c:1413 SYSC_sendfile64 fs/read_write.c:1468 [inline] SyS_sendfile64+0xbd/0x160 fs/read_write.c:1460 entry_SYSCALL_64_fastpath+0x29/0xa0 RIP: 0033:0x453299 RSP: 002b:00007fe5597e7c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000453299 RDX: 00000000200ddff8 RSI: 0000000000000015 RDI: 0000000000000013 RBP: 0000000000000622 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000100000001 R11: 0000000000000212 R12: 00000000006f83d0 R13: 00000000ffffffff R14: 00007fe5597e86d4 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by khungtaskd/757: #0: (rcu_read_lock){....}, at: [<000000006ce0d46c>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<000000006ce0d46c>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<00000000cf897d7b>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 2 locks held by getty/4089: #0: (&tty->ldisc_sem){++++}, at: [<00000000e23ed239>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b5c5b3f9>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4090: #0: (&tty->ldisc_sem){++++}, at: [<00000000e23ed239>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b5c5b3f9>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4091: #0: (&tty->ldisc_sem){++++}, at: [<00000000e23ed239>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b5c5b3f9>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4092: #0: (&tty->ldisc_sem){++++}, at: [<00000000e23ed239>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b5c5b3f9>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4093: #0: (&tty->ldisc_sem){++++}, at: [<00000000e23ed239>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b5c5b3f9>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4094: #0: (&tty->ldisc_sem){++++}, at: [<00000000e23ed239>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b5c5b3f9>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4095: #0: (&tty->ldisc_sem){++++}, at: [<00000000e23ed239>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b5c5b3f9>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 3 locks held by kworker/u4:10/8789: #0: ((wq_completion)"writeback"){+.+.}, at: [<00000000f766937f>] process_one_work+0xaaf/0x1af0 kernel/workqueue.c:2084 #1: ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: [<00000000e31f52d5>] process_one_work+0xb01/0x1af0 kernel/workqueue.c:2088 #2: (&type->s_umount_key#27){++++}, at: [<00000000922f057a>] trylock_super+0x20/0x100 fs/super.c:395 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 757 Comm: khungtaskd Not tainted 4.15.0+ #294 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x122/0x180 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:138 [inline] check_hung_task kernel/hung_task.c:132 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline] watchdog+0x90c/0xd60 kernel/hung_task.c:249 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:542 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.15.0+ #294 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:nr_iowait_cpu+0x0/0x120 kernel/sched/core.c:2932 RSP: 0018:ffff8801db507ce0 EFLAGS: 00000016 RAX: 00000000003934ed RBX: 0000000000000000 RCX: ffffffff81642ead RDX: 1ffff1003b6a4cd5 RSI: ffff8801db526620 RDI: 0000000000000001 RBP: ffff8801db507d18 R08: ffff88021fff805c R09: ffff88021fff8048 R10: ffff88021fff8050 R11: ffff88021fff805d R12: 00000072d90a70a7 R13: 0000000000000001 R14: ffff8801db5266a8 R15: ffff8801db526620 FS: 0000000000000000(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0633e9d140 CR3: 0000000006a22001 CR4: 00000000001606e0 Call Trace: tick_nohz_stop_idle kernel/time/tick-sched.c:536 [inline] tick_nohz_irq_enter kernel/time/tick-sched.c:1150 [inline] tick_irq_enter+0x262/0x390 kernel/time/tick-sched.c:1169 irq_enter+0xb6/0xd0 kernel/softirq.c:346 scheduler_ipi+0x23d/0x820 kernel/sched/core.c:1794 smp_reschedule_interrupt+0xe6/0x670 arch/x86/kernel/smp.c:277 reschedule_interrupt+0xa9/0xb0 arch/x86/entry/entry_64.S:962 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54 RSP: 0018:ffff8801d9f1fcb0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02 RAX: dffffc0000000000 RBX: 1ffff1003b3e3f99 RCX: 0000000000000000 RDX: 1ffffffff0d59280 RSI: 0000000000000001 RDI: ffffffff86ac9400 RBP: ffff8801d9f1fcb0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: ffff8801d9f1fd68 R14: ffffffff87268d20 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:93 [inline] default_idle+0xbf/0x430 arch/x86/kernel/process.c:354 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:345 default_idle_call+0x36/0x90 kernel/sched/idle.c:98 cpuidle_idle_call kernel/sched/idle.c:156 [inline] do_idle+0x24a/0x3b0 kernel/sched/idle.c:246 cpu_startup_entry+0x104/0x120 kernel/sched/idle.c:351 start_secondary+0x40a/0x590 arch/x86/kernel/smpboot.c:267 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:237 Code: e9 f6 fe ff ff 48 89 85 60 ff ff ff 4c 89 8d 68 ff ff ff e8 d3 85 5b 00 48 8b 85 60 ff ff ff 4c 8b 8d 68 ff ff ff e9 97 fe ff ff <55> 48 ba 00 00 00 00 00 fc ff df 48 89 e5 41 55 41 54 4c 8d 65