device lo left promiscuous mode
INFO: task syz-executor3:13157 blocked for more than 120 seconds.
      Not tainted 4.9.95-gee0bcd6 #6
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor3   D29352 13157   3871 0x00000004
 ffff8801cc7de000 ffff880197ab4000 ffff8801cf0c5a40 ffff8801b7426000
 ffff8801db221b98 ffff8801a3437aa0 ffffffff839e140d 1ffff10034686f48
 ffffffff85341f38 0000000041b58ab3 00ffffff841c0568 ffff8801db222468
Call Trace:
 [<ffffffff839e2a0f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff839eee21>] schedule_timeout+0x861/0xf70 kernel/time/timer.c:1768
 [<ffffffff839e0bea>] io_schedule_timeout+0x1ba/0x390 kernel/sched/core.c:5180
 [<ffffffff839e4343>] do_wait_for_common kernel/sched/completion.c:75 [inline]
 [<ffffffff839e4343>] __wait_for_common kernel/sched/completion.c:93 [inline]
 [<ffffffff839e4343>] wait_for_common_io kernel/sched/completion.c:107 [inline]
 [<ffffffff839e4343>] wait_for_completion_io+0x203/0x2e0 kernel/sched/completion.c:155
 [<ffffffff81df8782>] submit_bio_wait+0x112/0x180 block/bio.c:885
 [<ffffffff81e2aed2>] blkdev_issue_flush+0x152/0x220 block/blk-flush.c:518
 [<ffffffff8162c7f5>] blkdev_fsync+0x85/0xb0 fs/block_dev.c:378
 [<ffffffff81617dfc>] vfs_fsync_range+0x10c/0x260 fs/sync.c:195
 [<ffffffff81617fc2>] vfs_fsync fs/sync.c:209 [inline]
 [<ffffffff81617fc2>] do_fsync+0x42/0xb0 fs/sync.c:219
 [<ffffffff81618746>] SYSC_fsync fs/sync.c:228 [inline]
 [<ffffffff81618746>] SyS_fsync+0x16/0x20 fs/sync.c:226
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f2313>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/518:
 #0:  (rcu_read_lock){......}, at: [<ffffffff813646bc>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff813646bc>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81423cb0>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
2 locks held by getty/3771:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839f04b2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<ffffffff8211cb02>] n_tty_read+0x202/0x16b0 drivers/tty/n_tty.c:2133

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

NMI backtrace for cpu 1
CPU: 1 PID: 518 Comm: khungtaskd Not tainted 4.9.95-gee0bcd6 #6
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d8727d08 ffffffff81eb0f89 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810b7d60 ffff8801d8727d40
 ffffffff81ebc2b7 0000000000000001 0000000000000000 0000000000000002
Call Trace:
 [<ffffffff81eb0f89>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb0f89>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebc2b7>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebc24a>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810b7e64>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81364c54>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81364c54>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81364c54>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81364c54>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119ad2d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f24dc>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3673 Comm: rs:main Q:Reg Not tainted 4.9.95-gee0bcd6 #6
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801b8ec3000 task.stack: ffff8801b80c0000
RIP: 0010:[<ffffffff812337d2>] 
c [<ffffffff812337d2>] mark_held_locks+0xb2/0x130 kernel/locking/lockdep.c:2652
RSP: 0018:ffff8801b80c7598  EFLAGS: 00000046
RAX: 0000000000000004 RBX: 0000000000000002 RCX: 1ffff100371d8722
RDX: 0000000000000002 RSI: ffff8801b8ec3918 RDI: ffff8801b8ec393a
RBP: ffff8801b80c75d8 R08: ffff8801b8ec3910 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801b8ec38c8
R13: ffffed00371d8718 R14: ffff8801b8ec3000 R15: dffffc0000000000
FS:  00007f22ae964700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c4201b1e80 CR3: 00000001b8a24000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 0000000000000000
c ffff8801b8ec38c0
c 0000000600000007
c ffff8801b8ec3000
c
 ffffffff839f1a0a
c 0000000000001003
c 0000000000000040
c ffff8801cdb58118
c
 ffff8801b80c75f8
c ffffffff81233bdb
c 0000000000000282
c ffff8801cdb58118
c
Call Trace:
 [<ffffffff81233bdb>] __trace_hardirqs_on_caller kernel/locking/lockdep.c:2689 [inline]
 [<ffffffff81233bdb>] trace_hardirqs_on_caller+0x38b/0x590 kernel/locking/lockdep.c:2736
 [<ffffffff81233ded>] trace_hardirqs_on+0xd/0x10 kernel/locking/lockdep.c:2743
 [<ffffffff839f1a0a>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:162 [inline]
 [<ffffffff839f1a0a>] _raw_spin_unlock_irqrestore+0x5a/0x70 kernel/locking/spinlock.c:191
 [<ffffffff81f57134>] __percpu_counter_sum+0x134/0x190 lib/percpu_counter.c:110
 [<ffffffff8171ebdb>] percpu_counter_sum_positive include/linux/percpu_counter.h:58 [inline]
 [<ffffffff8171ebdb>] ext4_has_free_clusters+0x3cb/0x4b0 fs/ext4/balloc.c:557
 [<ffffffff817203b9>] ext4_should_retry_alloc+0x49/0x200 fs/ext4/balloc.c:609
 [<ffffffff81753cc5>] ext4_da_write_begin+0x375/0x1020 fs/ext4/inode.c:3018
 [<ffffffff81433c81>] generic_perform_write+0x301/0x510 mm/filemap.c:2741
 [<ffffffff8143b702>] __generic_file_write_iter+0x352/0x540 mm/filemap.c:2866
 [<ffffffff8172a093>] ext4_file_write_iter+0x463/0xd90 fs/ext4/file.c:165
 [<ffffffff8156c4a0>] new_sync_write fs/read_write.c:496 [inline]
 [<ffffffff8156c4a0>] __vfs_write+0x3e0/0x580 fs/read_write.c:509
 [<ffffffff81570297>] vfs_write+0x187/0x530 fs/read_write.c:557
 [<ffffffff815740c9>] SYSC_write fs/read_write.c:604 [inline]
 [<ffffffff815740c9>] SyS_write+0xd9/0x1c0 fs/read_write.c:596
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f2313>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
cc3 
c48 
c8d 
c04 
c80 
c49 
c8d 
c34 
cc4 
c48 
c8d 
c7e 
c22 
c48 
c89 
cf8 
c48 
c89 
cfa 
c48 
cc1 
ce8 
c03 
c83 
ce2 
c07 
c42 
c0f 
cb6 
c04 
c38 
c38 
cd0 
c7f 
c04 
c84 
cc0 
c75 
c5e 
c0f 
cb6 
c46 
c22 
c<8b> 
c55 
cd4 
ca8 
c03 
c0f 
c45 
c55 
cd0 
ca8 
c04 
c74 
c0c 
c4c 
c89 
cf7 
ce8 
cb9 
cec 
cff 
cff 
c