INFO: task syz-executor311:9472 blocked for more than 143 seconds. Not tainted 5.5.0-rc2-next-20191220-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor311 D26672 9472 9470 0x00004000 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4081 schedule+0xdc/0x2b0 kernel/sched/core.c:4155 io_schedule+0x1c/0x70 kernel/sched/core.c:5799 wait_on_page_bit_common mm/filemap.c:1175 [inline] wait_on_page_bit+0x27c/0xa60 mm/filemap.c:1224 wait_on_page_writeback+0x1b2/0x4f0 mm/page-writeback.c:2822 __filemap_fdatawait_range+0x145/0x340 mm/filemap.c:526 filemap_fdatawait_keep_errors+0x22/0x30 mm/filemap.c:621 wait_sb_inodes fs/fs-writeback.c:2436 [inline] sync_inodes_sb+0x6e4/0xb50 fs/fs-writeback.c:2558 __sync_filesystem fs/sync.c:34 [inline] sync_filesystem fs/sync.c:67 [inline] sync_filesystem+0x168/0x260 fs/sync.c:48 generic_shutdown_super+0x75/0x370 fs/super.c:448 kill_block_super+0xa0/0x100 fs/super.c:1444 deactivate_locked_super+0x95/0x100 fs/super.c:335 deactivate_super fs/super.c:366 [inline] deactivate_super+0x1bd/0x1e0 fs/super.c:362 cleanup_mnt+0x351/0x4c0 fs/namespace.c:1102 __cleanup_mnt+0x16/0x20 fs/namespace.c:1109 task_work_run+0x145/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x316/0x380 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath arch/x86/entry/common.c:278 [inline] do_syscall_64+0x676/0x790 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4487d7 Code: Bad RIP value. RSP: 002b:00007ffd80252528 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000044a73 RCX: 00000000004487d7 RDX: 0000000000400c50 RSI: 0000000000000002 RDI: 00007ffd802525d0 RBP: 0000000000002509 R08: 0000000000000000 R09: 0000000000000009 R10: 0000000000000005 R11: 0000000000000206 R12: 00007ffd80253630 R13: 0000000000f59940 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/1116: #0: ffffffff899af980 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5334 1 lock held by rsyslogd/9356: #0: ffff8880a462fde0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:803 2 locks held by getty/9446: #0: ffff888097195090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900016cb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9447: #0: ffff8880a89dd090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900016eb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9448: #0: ffff888093c24090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900016db2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9449: #0: ffff888095675090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900016fb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9450: #0: ffff8880a6d3e090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000170b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9451: #0: ffff888094b7e090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000166b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9452: #0: ffff888099570090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900011302e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by syz-executor311/9472: #0: ffff8880a05d80d8 (&type->s_umount_key#41){+.+.}, at: deactivate_super fs/super.c:365 [inline] #0: ffff8880a05d80d8 (&type->s_umount_key#41){+.+.}, at: deactivate_super+0x1b5/0x1e0 fs/super.c:362 #1: ffff8880a05d88b8 (&s->s_sync_lock){+.+.}, at: wait_sb_inodes fs/fs-writeback.c:2375 [inline] #1: ffff8880a05d88b8 (&s->s_sync_lock){+.+.}, at: sync_inodes_sb+0x246/0xb50 fs/fs-writeback.c:2558 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1116 Comm: khungtaskd Not tainted 5.5.0-rc2-next-20191220-syzkaller #0 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+0x197/0x210 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b 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:249 [inline] watchdog+0xdf1/0x14e0 kernel/hung_task.c:333 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.5.0-rc2-next-20191220-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x50 kernel/kcov.c:180 Code: ff cc cc cc cc cc cc cc cc cc 65 48 8b 04 25 c0 1e 02 00 48 8b 80 a0 13 00 00 c3 0f 1f 44 00 00 66 2e 0f 1f 84 00 00 00 00 00 <55> 48 89 e5 65 48 8b 04 25 c0 1e 02 00 65 8b 15 e4 c8 8c 7e 81 e2 RSP: 0018:ffffc90000da8cf0 EFLAGS: 00000006 RAX: ffff8880a99fa340 RBX: 0000000000000000 RCX: ffffffff817aed90 RDX: 0000000000000100 RSI: ffffffff817aedcc RDI: 0000000000000005 RBP: ffffc90000da8d28 R08: ffff8880a99fa340 R09: ffffed1015d26ead R10: ffffed1015d26eac R11: ffff8880ae937563 R12: ffff8880ae937500 R13: ffffffff8153c3ee R14: ffffffff87cf768f R15: 0000000000000040 FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f31b908f000 CR3: 0000000093894000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline] _raw_spin_lock_irqsave+0x6f/0xcd kernel/locking/spinlock.c:159 rq_lock_irqsave kernel/sched/sched.h:1199 [inline] update_blocked_averages+0x4e/0x13d0 kernel/sched/fair.c:7646 _nohz_idle_balance+0x2e8/0x3f0 kernel/sched/fair.c:9986 nohz_idle_balance kernel/sched/fair.c:10037 [inline] run_rebalance_domains+0x1c6/0x2d0 kernel/sched/fair.c:10226 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 scheduler_ipi+0x3ae/0x640 kernel/sched/core.c:2348 smp_reschedule_interrupt+0x78/0x4c0 arch/x86/kernel/smp.c:244 reschedule_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:853 RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61 Code: 78 e4 e3 f9 eb 8a cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d b4 1b 59 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d a4 1b 59 00 fb f4 cc 55 48 89 e5 41 57 41 56 41 55 41 54 53 e8 2e 88 93 f9 e8 79 RSP: 0018:ffffc90000d3fd68 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff02 RAX: 1ffffffff13275ce RBX: ffff8880a99fa340 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffff8880a99fabdc RBP: ffffc90000d3fd98 R08: ffff8880a99fa340 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: ffffffff8a816ac0 R14: 0000000000000000 R15: 0000000000000001 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:686 default_idle_call+0x84/0xb0 kernel/sched/idle.c:94 cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x3c8/0x6e0 kernel/sched/idle.c:269 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:361 start_secondary+0x2f4/0x410 arch/x86/kernel/smpboot.c:264 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242