INFO: task syz-executor6:7627 blocked for more than 120 seconds.
      Not tainted 4.9.64-gfbb7468 #94
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor6   D28032  7627   3553 0x00000004
 ffff8801aa046000 0000000000000000 ffff8801ccde3480 ffff8801da29b000
 ffff8801db321418 ffff8801ce1c7950 ffffffff83897fdb ffffffff812395a0
 ffffffff8418f098 00ffffff812395a0 ffff8801db321d40 ffff8801db321d68
Call Trace:
 [<ffffffff8389957f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3540
 [<ffffffff838a57b3>] schedule_timeout+0x643/0x1220 kernel/time/timer.c:1770
 [<ffffffff8389778e>] io_schedule_timeout+0x1be/0x390 kernel/sched/core.c:5162
 [<ffffffff8389a9f9>] io_schedule include/linux/sched.h:460 [inline]
 [<ffffffff8389a9f9>] bit_wait_io+0x19/0xa0 kernel/sched/wait.c:582
 [<ffffffff8389a262>] __wait_on_bit_lock+0xc2/0x1c0 kernel/sched/wait.c:421
 [<ffffffff8142fd7f>] __lock_page+0xff/0x160 mm/filemap.c:934
 [<ffffffff814695ea>] lock_page include/linux/pagemap.h:454 [inline]
 [<ffffffff814695ea>] truncate_inode_pages_range+0xc1a/0x12c0 mm/truncate.c:373
 [<ffffffff81628221>] blkdev_fallocate+0x221/0x440 fs/block_dev.c:1817
 [<ffffffff81561e0a>] vfs_fallocate+0x33a/0x5f0 fs/open.c:329
 [<ffffffff81564e33>] SYSC_fallocate fs/open.c:352 [inline]
 [<ffffffff81564e33>] SyS_fallocate+0x53/0x90 fs/open.c:346
 [<ffffffff838a9785>] entry_SYSCALL_64_fastpath+0x23/0xc6

Showing all locks held in the system:
2 locks held by khungtaskd/514:
 #0:  (rcu_read_lock){......}, at: [<ffffffff8136fed5>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8136fed5>] watchdog+0x125/0xa70 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81235700>] debug_show_all_locks+0x70/0x280 kernel/locking/lockdep.c:4336
2 locks held by getty/3203:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff838a79a2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<ffffffff82001b14>] n_tty_read+0x1f4/0x16c0 drivers/tty/n_tty.c:2133
1 lock held by syz-executor6/7627:
 #0:  (sb_writers){.+.+.+}, at: [<ffffffff81561db1>] sb_start_write include/linux/fs.h:1554 [inline]
 #0:  (sb_writers){.+.+.+}, at: [<ffffffff81561db1>] vfs_fallocate+0x2e1/0x5f0 fs/open.c:328
1 lock held by syz-executor6/7634:
 #0:  (sb_writers){.+.+.+}, at: [<ffffffff81561db1>] sb_start_write include/linux/fs.h:1554 [inline]
 #0:  (sb_writers){.+.+.+}, at: [<ffffffff81561db1>] vfs_fallocate+0x2e1/0x5f0 fs/open.c:328

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 514 Comm: khungtaskd Not tainted 4.9.64-gfbb7468 #94
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d99efd00 ffffffff81d90429 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810ba170 ffff8801d99efd38
 ffffffff81d9b54d 0000000000000001 0000000000000000 ffff8801cbe8b418
Call Trace:
 [<ffffffff81d90429>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d90429>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81d9b54d>] nmi_cpu_backtrace+0xfd/0x120 lib/nmi_backtrace.c:99
 [<ffffffff81d9b687>] nmi_trigger_cpumask_backtrace+0x117/0x190 lib/nmi_backtrace.c:60
 [<ffffffff810ba264>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff813704a0>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff813704a0>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff813704a0>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff813704a0>] watchdog+0x6f0/0xa70 kernel/hung_task.c:239
 [<ffffffff811985dd>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838a9a2a>] ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:433
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff838a8416