INFO: task syz-executor.5:2616 blocked for more than 140 seconds.
      Not tainted 4.4.174+ #4
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D ffff8801d4ef7a18 30048  2616   2117 0x00000004
 ffff8801d4ef7a18 ffff8800b92fdf00 fe8db8a9193fbd92 ffff8800b92fdf00
 0000000000000002 ffff8800b92fe700 ffff8801db71f180 ffff8801db71f1a8
 ffff8801db71e898 ffff8800a5bd0000 ffff8800b92fdf00 ffffed003a9de001
Call Trace:
 [<ffffffff82709b79>] schedule+0x99/0x1d0 kernel/sched/core.c:3355
 [<ffffffff8270a333>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3388
 [<ffffffff8270c492>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff8270c492>] mutex_lock_nested+0x3c2/0xb80 kernel/locking/mutex.c:621
 [<ffffffff816334ac>] ext4_file_write_iter+0x15c/0xc70 fs/ext4/file.c:116
 [<ffffffff81496ae8>] new_sync_write fs/read_write.c:480 [inline]
 [<ffffffff81496ae8>] __vfs_write+0x2e8/0x3d0 fs/read_write.c:493
 [<ffffffff81498612>] vfs_write+0x182/0x4e0 fs/read_write.c:540
 [<ffffffff8149ac4c>] SYSC_write fs/read_write.c:587 [inline]
 [<ffffffff8149ac4c>] SyS_write+0xdc/0x1c0 fs/read_write.c:579
 [<ffffffff82718ba1>] entry_SYSCALL_64_fastpath+0x1e/0x9a
3 locks held by syz-executor.5/2616:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff814f4378>] __fdget_pos+0xa8/0xd0 fs/file.c:780
 #1:  (sb_writers#4){.+.+.+}, at: [<ffffffff814987cb>] file_start_write include/linux/fs.h:2543 [inline]
 #1:  (sb_writers#4){.+.+.+}, at: [<ffffffff814987cb>] vfs_write+0x33b/0x4e0 fs/read_write.c:539
 #2:  (&sb->s_type->i_mutex_key#9){+.+.+.}, at: [<ffffffff816334ac>] ext4_file_write_iter+0x15c/0xc70 fs/ext4/file.c:116
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 20 Comm: khungtaskd Not tainted 4.4.174+ #4
task: ffff8801da6f4740 task.stack: ffff8800001d0000
RIP: 0010:[<ffffffff8109b617>]  [<ffffffff8109b617>] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:62 [inline]
RIP: 0010:[<ffffffff8109b617>]  [<ffffffff8109b617>] flat_send_IPI_mask+0xf7/0x1b0 arch/x86/kernel/apic/apic_flat_64.c:69
RSP: 0018:ffff8800001d7c88  EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fc300
RBP: ffff8800001d7cb8 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000246
R13: 0000000003000000 R14: ffffffff82e5f2e0 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c42bc7bc40 CR3: 00000000ba23b000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 0000000000000001 ffffffff82e5f2e0 ffffffff831a6ac0 fffffbfff0634c34
 000000000001b6c0 0000000000000008 ffff8800001d7cd8 ffffffff81092bee
 0000000000000008 ffffffff82924260 ffff8800001d7d30 ffffffff81ab8252
Call Trace:
 [<ffffffff81092bee>] nmi_raise_cpu_backtrace+0x5e/0x80 arch/x86/kernel/apic/hw_nmi.c:33
 [<ffffffff81ab8252>] nmi_trigger_all_cpu_backtrace.cold+0xa1/0xae lib/nmi_backtrace.c:85
 [<ffffffff81092ca4>] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 [<ffffffff813b4762>] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline]
 [<ffffffff813b4762>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff813b4762>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff813b4762>] watchdog.cold+0xd3/0xee kernel/hung_task.c:238
 [<ffffffff811342c3>] kthread+0x273/0x310 kernel/kthread.c:211
 [<ffffffff82718fc5>] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:537
Code: 00 c3 5f ff 80 e6 10 75 e1 41 c1 e5 18 44 89 2c 25 10 c3 5f ff 44 89 fa 09 da 80 cf 04 41 83 ff 02 0f 44 d3 89 14 25 00 c3 5f ff <41> f7 c4 00 02 00 00 75 1e 4c 89 e7 57 9d 0f 1f 44 00 00 e8 f1 
NMI backtrace for cpu 1
CPU: 1 PID: 2610 Comm: syz-executor.5 Not tainted 4.4.174+ #4
task: ffff8800b92fc740 task.stack: ffff8800a5ba8000
RIP: 0010:[<ffffffff81309610>]  [<ffffffff81309610>] __read_once_size include/linux/compiler.h:218 [inline]
RIP: 0010:[<ffffffff81309610>]  [<ffffffff81309610>] check_kcov_mode kernel/kcov.c:68 [inline]
RIP: 0010:[<ffffffff81309610>]  [<ffffffff81309610>] __sanitizer_cov_trace_pc+0x20/0x50 kernel/kcov.c:100
RSP: 0018:ffff8800a5bafd20  EFLAGS: 00000246
RAX: ffff8800b92fc740 RBX: ffff8800a5bafe78 RCX: ffff8800b92fd008
RDX: 0000000000000000 RSI: ffffffff81743884 RDI: 0000000000000246
RBP: ffff8800a5bafd20 R08: 0000000000000002 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8800b85c31c0
R13: 000000000c95f699 R14: 000000000c95f699 R15: 0000000000000000
FS:  00007fdd5d157700(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fca35e2e330 CR3: 00000001d99fe000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8800a5bafd70 ffffffff81743884 ffff8800b85c35d8 0c95f69900000286
 ffff8800b85c31c0 ffff8800a5bafee8 ffff8800b85c31c0 000000000c95f699
 ffff8801d4cd7800 0000000000000000 ffff8800a5baff10 ffffffff81634dfb
Call Trace:
 [<ffffffff81743884>] rcu_read_unlock_sched_notrace include/linux/rcupdate.h:1007 [inline]
 [<ffffffff81743884>] trace_ext4_es_find_delayed_extent_range_enter include/trace/events/ext4.h:2310 [inline]
 [<ffffffff81743884>] ext4_es_find_delayed_extent_range+0x4c4/0xab0 fs/ext4/extents_status.c:254
 [<ffffffff81634dfb>] ext4_seek_data fs/ext4/file.c:587 [inline]
 [<ffffffff81634dfb>] ext4_llseek+0x6bb/0x970 fs/ext4/file.c:717
 [<ffffffff81497af3>] vfs_llseek fs/read_write.c:260 [inline]
 [<ffffffff81497af3>] SYSC_lseek fs/read_write.c:285 [inline]
 [<ffffffff81497af3>] SyS_lseek+0x113/0x180 fs/read_write.c:276
 [<ffffffff82718cb7>] tracesys+0x88/0x8d
Code: d7 b8 17 00 e9 42 fe ff ff 66 90 55 48 89 e5 48 8b 75 08 65 48 8b 04 25 80 67 01 00 65 8b 15 08 d1 d0 7e 81 e2 00 01 1f 00 75 2b <8b> 90 50 12 00 00 83 fa 02 75 20 48 8b 88 58 12 00 00 8b 80 54