INFO: task syz-executor4:9168 blocked for more than 120 seconds. Not tainted 4.16.0-rc7+ #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D24608 9168 4471 0x00000004 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440 schedule+0xf5/0x430 kernel/sched/core.c:3499 io_schedule+0x1c/0x70 kernel/sched/core.c:5115 wait_on_page_bit_common mm/filemap.c:1099 [inline] __lock_page+0x574/0x720 mm/filemap.c:1272 lock_page include/linux/pagemap.h:483 [inline] pagecache_get_page+0x674/0xba0 mm/filemap.c:1553 find_lock_page include/linux/pagemap.h:297 [inline] truncate_inode_pages_range+0xc37/0x1fe0 mm/truncate.c:396 blkdev_fallocate+0x1ff/0x3b0 fs/block_dev.c:2006 vfs_fallocate+0x33c/0x6f0 fs/open.c:319 SYSC_fallocate fs/open.c:342 [inline] SyS_fallocate+0x53/0x90 fs/open.c:336 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x454889 RSP: 002b:00007ff434143c68 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007ff4341446d4 RCX: 0000000000454889 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000013 RBP: 000000000072bf58 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000800 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000007d R14: 00000000006f2c58 R15: 0000000000000001 Showing all locks held in the system: 2 locks held by khungtaskd/869: #0: (rcu_read_lock){....}, at: [<000000003b4f06c1>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<000000003b4f06c1>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<000000003e69dc3e>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 2 locks held by rs:main Q:Reg/4299: #0: (&f->f_pos_lock){+.+.}, at: [<00000000e18ee793>] __fdget_pos+0x12b/0x190 fs/file.c:765 #1: (sb_writers#4){.+.+}, at: [<00000000ba0480df>] file_start_write include/linux/fs.h:2709 [inline] #1: (sb_writers#4){.+.+}, at: [<00000000ba0480df>] vfs_write+0x407/0x510 fs/read_write.c:543 2 locks held by getty/4391: #0: (&tty->ldisc_sem){++++}, at: [<00000000e728e36c>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ac36a133>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4392: #0: (&tty->ldisc_sem){++++}, at: [<00000000e728e36c>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ac36a133>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4393: #0: (&tty->ldisc_sem){++++}, at: [<00000000e728e36c>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ac36a133>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4394: #0: (&tty->ldisc_sem){++++}, at: [<00000000e728e36c>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ac36a133>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4395: #0: (&tty->ldisc_sem){++++}, at: [<00000000e728e36c>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ac36a133>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4396: #0: (&tty->ldisc_sem){++++}, at: [<00000000e728e36c>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ac36a133>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4397: #0: (&tty->ldisc_sem){++++}, at: [<00000000e728e36c>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ac36a133>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 869 Comm: khungtaskd Not tainted 4.16.0-rc7+ #3 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+0x194/0x24d lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x123/0x180 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:406 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.16.0-rc7+ #3 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__preempt_count_add arch/x86/include/asm/preempt.h:76 [inline] RIP: 0010:rcu_read_lock_sched_notrace include/linux/rcupdate.h:754 [inline] RIP: 0010:trace_softirq_raise include/trace/events/irq.h:156 [inline] RIP: 0010:__raise_softirq_irqoff kernel/softirq.c:443 [inline] RIP: 0010:raise_softirq_irqoff+0x220/0x320 kernel/softirq.c:417 RSP: 0018:ffff8801db207c90 EFLAGS: 00000083 RAX: 0000000000000000 RBX: 1ffff1003b640f93 RCX: dffffc0000000000 RDX: 1ffff1003b645a0a RSI: 1ffff1003b640fc5 RDI: 0000000000000007 RBP: ffff8801db207d60 R08: 1ffff1003b6459fd R09: ffff88021fff8008 R10: ffff88021fff8010 R11: ffff88021fff801d R12: 0000000000000007 R13: ffff8801db207d38 R14: ffff8801db207e68 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000202e000 CR3: 0000000007a22001 CR4: 00000000001606f0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: scheduler_ipi+0x50b/0x820 kernel/sched/core.c:1802 smp_reschedule_interrupt+0xe6/0x650 arch/x86/kernel/smp.c:277 reschedule_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:881 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54 RSP: 0018:ffffffff87a07c38 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff02 RAX: dffffc0000000000 RBX: 1ffffffff0f40f8a RCX: 0000000000000000 RDX: 1ffffffff0f59580 RSI: 0000000000000001 RDI: ffffffff87acac00 RBP: ffffffff87a07c38 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff87a07cf0 R14: ffffffff883b4a20 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [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 rest_init+0xed/0xf0 init/main.c:437 start_kernel+0x7f1/0x819 init/main.c:717 x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:378 x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:359 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:239 Code: 89 f2 48 c1 ea 03 80 3c 02 00 0f 85 d4 00 00 00 4d 8b 3e 4d 85 ff 75 b6 65 ff 0d cc 38 be 7e e9 62 fe ff ff 65 ff 05 c0 38 be 7e <49> 8d 45 c0 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 48 01 d0