INFO: task hung in do_page_mkwriteINFO: task syz-fuzzer:4897 blocked for more than 140 seconds. Not tainted 4.19.0-rc2-next-20180905+ #59 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-fuzzer D21704 4897 4895 0x00000000 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x87c/0x1df0 kernel/sched/core.c:3473 schedule+0xfb/0x450 kernel/sched/core.c:3517 io_schedule+0x1c/0x70 kernel/sched/core.c:5140 wait_on_page_bit_common mm/filemap.c:1100 [inline] __lock_page+0x5b7/0x7a0 mm/filemap.c:1273 lock_page include/linux/pagemap.h:483 [inline] do_page_mkwrite+0x429/0x520 mm/memory.c:2391 do_shared_fault mm/memory.c:3717 [inline] do_fault mm/memory.c:3756 [inline] handle_pte_fault mm/memory.c:3983 [inline] __handle_mm_fault+0x2a0a/0x4350 mm/memory.c:4107 handle_mm_fault+0x53e/0xc80 mm/memory.c:4144 __do_page_fault+0x620/0xe50 arch/x86/mm/fault.c:1395 do_page_fault+0xf6/0x7a4 arch/x86/mm/fault.c:1470 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1164 RIP: 0033:0x70b581 Code: 48 89 6c 24 10 48 8d 6c 24 10 48 8b 44 24 20 48 8b 48 08 48 8b 50 10 48 8d 58 08 48 83 fa 08 0f 8c 1e 01 00 00 48 8b 54 24 28 <88> 11 48 8b 48 08 48 8b 70 10 48 83 fe 01 0f 86 44 01 00 00 48 89 RSP: 002b:000000c42015f3f0 EFLAGS: 00010212 RAX: 000000c42015f508 RBX: 000000c42015f510 RCX: 00007f913663b000 RDX: 0000000000000543 RSI: 000000000072a460 RDI: 000000c42015f348 RBP: 000000c42015f400 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000949c4a R11: 0000000000000004 R12: 0000000000000000 R13: 0000000000000020 R14: 0000000000000013 R15: 000000000000000f Showing all locks held in the system: 4 locks held by kworker/u4:3/114: #0: 00000000ec49771a ((wq_completion)"writeback"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 00000000ec49771a ((wq_completion)"writeback"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000ec49771a ((wq_completion)"writeback"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000ec49771a ((wq_completion)"writeback"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000ec49771a ((wq_completion)"writeback"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000ec49771a ((wq_completion)"writeback"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000ec49771a ((wq_completion)"writeback"){+.+.}, at: process_one_work+0xb44/0x1aa0 kernel/workqueue.c:2124 #1: 0000000006bb612a ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0xb9b/0x1aa0 kernel/workqueue.c:2128 #2: 000000008c900010 (&fc->fs_type->s_umount_key#29){++++}, at: trylock_super+0x22/0x110 fs/super.c:411 #3: 000000000210d5f0 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0x9a/0x1a0 mm/page-writeback.c:2340 1 lock held by khungtaskd/794: #0: 000000003a3f0e27 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4436 1 lock held by khugepaged/800: #0: 00000000f1c4d70f (&mm->mmap_sem){++++}, at: collapse_huge_page+0x2bf/0x2250 mm/khugepaged.c:1007 2 locks held by getty/4875: #0: 000000003272299c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000fee10f4f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4876: #0: 00000000d4d2e39c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000bf69dc6e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4877: #0: 0000000049c730cb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000551cdd76 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4878: #0: 000000005786aa00 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000016fd2fc9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4879: #0: 00000000d836905f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000d6ed2b80 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4880: #0: 0000000077115452 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000c844775d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4881: #0: 00000000e04709ea (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000fb2e0e5a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 1 lock held by syz-fuzzer/4897: #0: 00000000f1c4d70f (&mm->mmap_sem){++++}, at: __do_page_fault+0x389/0xe50 arch/x86/mm/fault.c:1324 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 794 Comm: khungtaskd Not tainted 4.19.0-rc2-next-20180905+ #59 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+0x1c9/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.4+0x48/0x88 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b6/0x1cd 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+0xb39/0x1040 kernel/hung_task.c:265 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.19.0-rc2-next-20180905+ #59 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:check_preempt_curr+0x6f/0x3a0 kernel/sched/core.c:840 Code: 00 fc ff df 4c 89 c7 48 c1 ef 03 80 3c 07 00 0f 85 9a 02 00 00 4c 8b b9 20 0a 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d 7f 78 <49> 89 f9 49 c1 e9 03 41 80 3c 01 00 0f 85 4b 02 00 00 4d 8b 67 78 RSP: 0018:ffff8801db107200 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffff8801b1efe080 RCX: ffff8801db12cc80 RDX: 0000000000000000 RSI: ffff8801b1efe080 RDI: ffff8801d9f0e3f8 RBP: ffff8801db107248 R08: ffff8801db12d6a0 R09: ffff8801db12d750 R10: ffffed003b6246de R11: ffff8801db1236f3 R12: ffff8801db12cc80 R13: ffffffff872a9a80 R14: ffff8801db107308 R15: ffff8801d9f0e380 FS: 0000000000000000(0000) GS:ffff8801db100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001b6048000 CR4: 00000000001406e0 Call Trace: ttwu_do_wakeup+0x90/0x6b0 kernel/sched/core.c:1652 ttwu_do_activate+0x146/0x1f0 kernel/sched/core.c:1698 ttwu_queue kernel/sched/core.c:1842 [inline] try_to_wake_up+0x928/0x1250 kernel/sched/core.c:2051 wake_up_process+0x10/0x20 kernel/sched/core.c:2123 hrtimer_wakeup+0x48/0x60 kernel/time/hrtimer.c:1646 __run_hrtimer kernel/time/hrtimer.c:1398 [inline] __hrtimer_run_queues+0x3eb/0xff0 kernel/time/hrtimer.c:1460 hrtimer_interrupt+0x2f3/0x750 kernel/time/hrtimer.c:1518 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1029 [inline] smp_apic_timer_interrupt+0x16d/0x6a0 arch/x86/kernel/apic/apic.c:1054 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:867 RIP: 0010:arch_local_irq_enable arch/x86/include/asm/paravirt.h:798 [inline] RIP: 0010:__do_softirq+0x2a3/0xa74 kernel/softirq.c:276 Code: c7 c0 b8 be 11 88 48 c1 e8 03 42 80 3c 28 00 0f 85 aa 06 00 00 48 83 3d 22 bc 11 01 00 0f 84 05 06 00 00 fb 66 0f 1f 44 00 00 <48> c7 85 68 fe ff ff 00 91 00 88 b8 ff ff ff ff 0f bc 85 74 fe ff RSP: 0018:ffff8801db107af0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff10237d7 RBX: ffff8801d9f0e380 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8801d9f0ebbc RBP: ffff8801db107cc8 R08: ffff8801d9f0e380 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801d9f0e380 R13: dffffc0000000000 R14: ffff8801db107e68 R15: 0000000000000001 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x1d6/0x210 kernel/softirq.c:412 scheduler_ipi+0x53c/0xa50 kernel/sched/core.c:1780 smp_reschedule_interrupt+0xfd/0x5e0 arch/x86/kernel/smp.c:278 reschedule_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:891 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57 Code: c7 48 89 45 d8 e8 ca 7a e5 fa 48 8b 45 d8 e9 d2 fe ff ff 48 89 df e8 b9 7a e5 fa eb 8a 90 90 90 90 90 90 90 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:ffff8801d9f1fc30 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02 RAX: dffffc0000000000 RBX: 1ffff1003b3e3f8a RCX: 0000000000000000 RDX: 1ffffffff10237d8 RSI: 0000000000000001 RDI: ffffffff8811bec0 RBP: ffff8801d9f1fc30 R08: ffff8801d9f0e380 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: ffff8801d9f1fcf0 R14: 0000000000000001 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0xc2/0x410 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+0x3aa/0x580 kernel/sched/idle.c:262 cpu_startup_entry+0x10c/0x120 kernel/sched/idle.c:368 start_secondary+0x433/0x5d0 arch/x86/kernel/smpboot.c:271 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242