INFO: task hung in do_page_mkwriteINFO: task syz-fuzzer:4910 blocked for more than 140 seconds. Not tainted 4.19.0-rc2-next-20180905+ #58 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-fuzzer D18248 4910 4904 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:000000c4200313f0 EFLAGS: 00010212 RAX: 000000c420031508 RBX: 000000c420031510 RCX: 00007f2838ed1000 RDX: 0000000000000543 RSI: 000000000072a460 RDI: 000000c420031348 RBP: 000000c420031400 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000949c4a R11: 0000000000000004 R12: 0000000000000000 R13: 0000000000000020 R14: 0000000000000013 R15: 000000000000000f Showing all locks held in the system: 1 lock held by khungtaskd/757: #0: 00000000a3250455 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4436 4 locks held by kworker/u4:5/776: #0: 00000000fd8a5b0a ((wq_completion)"writeback"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 00000000fd8a5b0a ((wq_completion)"writeback"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000fd8a5b0a ((wq_completion)"writeback"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000fd8a5b0a ((wq_completion)"writeback"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000fd8a5b0a ((wq_completion)"writeback"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000fd8a5b0a ((wq_completion)"writeback"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000fd8a5b0a ((wq_completion)"writeback"){+.+.}, at: process_one_work+0xb44/0x1aa0 kernel/workqueue.c:2124 #1: 0000000014cb626a ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0xb9b/0x1aa0 kernel/workqueue.c:2128 #2: 0000000040ac20cf (&fc->fs_type->s_umount_key#29){++++}, at: trylock_super+0x22/0x110 fs/super.c:411 #3: 00000000750cd6e6 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0x9a/0x1a0 mm/page-writeback.c:2340 1 lock held by khugepaged/801: #0: 000000009f7be133 (&mm->mmap_sem){++++}, at: collapse_huge_page+0x2bf/0x2250 mm/khugepaged.c:1007 3 locks held by rsyslogd/4793: #0: 000000002b8e4419 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 #1: 00000000323d6dca (logbuf_lock){-.-.}, at: aa_file_perm+0x10d/0xfc0 security/apparmor/file.c:611 #2: 00000000a3250455 (rcu_read_lock){....}, at: __update_idle_core+0xc4/0x610 kernel/sched/fair.c:5873 2 locks held by getty/4884: #0: 000000009866f08d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000097fe3cf8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4885: #0: 00000000129f08ac (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000002d3614d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4886: #0: 000000000d3d1d30 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000045512f2c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4887: #0: 000000007d09d6f6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000d67a9ede (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4888: #0: 000000004fcb7fe4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000006bee921e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4889: #0: 000000004e8c31e2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000940f2fbd (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4890: #0: 00000000ba821f93 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000fb9d6fac (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 1 lock held by syz-fuzzer/4910: #0: 000000009f7be133 (&mm->mmap_sem){++++}, at: __do_page_fault+0x389/0xe50 arch/x86/mm/fault.c:1324 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 757 Comm: khungtaskd Not tainted 4.19.0-rc2-next-20180905+ #58 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+ #58 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:pvclock_clocksource_read+0x1/0x680 arch/x86/kernel/pvclock.c:79 Code: 4c 8b 45 c8 0f b6 45 d0 eb a4 be 04 00 00 00 48 89 df e8 52 73 85 00 e9 15 ff ff ff 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 55 <48> 89 e5 41 57 41 56 48 8d 85 78 ff ff ff 41 55 48 c1 e8 03 41 54 RSP: 0018:ffff8801db107b80 EFLAGS: 00000082 RAX: ffffffff81352dd0 RBX: ffffffff8811b980 RCX: ffffffff816aad8e RDX: 0000000000000000 RSI: ffffffff816aada1 RDI: ffffffff88f79040 RBP: ffff8801db107b90 R08: ffff8801d9f0e380 R09: 0000000000000000 R10: 0000000000000003 R11: 0000000000000000 R12: dffffc0000000000 R13: 00000000000203ce R14: ffff8801db107c70 R15: ffffffff8811bea0 FS: 0000000000000000(0000) GS:ffff8801db100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001b8489000 CR4: 00000000001406e0 Call Trace: tk_clock_read kernel/time/timekeeping.c:170 [inline] timekeeping_get_delta kernel/time/timekeeping.c:264 [inline] timekeeping_get_ns kernel/time/timekeeping.c:371 [inline] ktime_get+0x248/0x440 kernel/time/timekeeping.c:756 tick_nohz_start_idle kernel/time/tick-sched.c:537 [inline] tick_nohz_irq_exit+0x7e/0x100 kernel/time/tick-sched.c:1009 tick_irq_exit kernel/softirq.c:394 [inline] irq_exit+0x1c0/0x210 kernel/softirq.c:414 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