INFO: task syz-executor4:25064 blocked for more than 120 seconds.
      Not tainted 4.4.138-gcf21a9a #62
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor4   D ffff8800a2327460 26360 25064   3909 0x20020004
 ffff8800a2327460 0000000000000040 ffff8800a2327598 d6b06258c1b5face
 ffff8800a2327600 ffff8801db21fdb8 ffff8801db21fde0 ffff8801db21f4d8
 ffff8801db21f4c0 ffff8801d93d3000 ffff8801c9064800 0000000000000000
Call Trace:
 [<ffffffff838b46ea>] schedule+0x7a/0x1b0 kernel/sched/core.c:3359
 [<ffffffff838bfb01>] schedule_timeout+0x481/0x8b0 kernel/time/timer.c:1515
 [<ffffffff838b25aa>] io_schedule_timeout+0x1ba/0x390 kernel/sched/core.c:4941
 [<ffffffff838b593b>] io_schedule include/linux/sched.h:447 [inline]
 [<ffffffff838b593b>] bit_wait_io+0x1b/0xd0 kernel/sched/wait.c:595
 [<ffffffff838b54a2>] __wait_on_bit_lock.part.4+0x92/0x140 kernel/sched/wait.c:434
 [<ffffffff838b5559>] __wait_on_bit_lock+0x9/0x10 kernel/sched/wait.c:427
 [<ffffffff8141cdfd>] __lock_page+0x17d/0x1f0 mm/filemap.c:888
 [<ffffffff815b9b0b>] lock_page include/linux/pagemap.h:458 [inline]
 [<ffffffff815b9b0b>] __generic_file_splice_read+0x7eb/0xbb0 fs/splice.c:412
 [<ffffffff815b9fb2>] generic_file_splice_read+0xe2/0x1c0 fs/splice.c:542
 [<ffffffff815b6107>] do_splice_to+0xf7/0x140 fs/splice.c:1154
 [<ffffffff815b6392>] splice_direct_to_actor+0x242/0x830 fs/splice.c:1226
 [<ffffffff815b6b23>] do_splice_direct+0x1a3/0x270 fs/splice.c:1337
 [<ffffffff815206c4>] do_sendfile+0x4e4/0xb80 fs/read_write.c:1227
 [<ffffffff81522811>] C_SYSC_sendfile fs/read_write.c:1303 [inline]
 [<ffffffff81522811>] compat_SyS_sendfile+0xd1/0x160 fs/read_write.c:1292
 [<ffffffff81006d96>] do_syscall_32_irqs_on arch/x86/entry/common.c:392 [inline]
 [<ffffffff81006d96>] do_fast_syscall_32+0x326/0x8b0 arch/x86/entry/common.c:459
 [<ffffffff838c406a>] sysenter_flags_fixed+0xd/0x17
no locks held by syz-executor4/25064.
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 3726 Comm: rsyslogd Not tainted 4.4.138-gcf21a9a #62
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801c88ce000 task.stack: ffff8800adb38000
RIP: 0010:[<ffffffff8122a385>]  [<ffffffff8122a385>] arch_local_save_flags arch/x86/include/asm/paravirt.h:807 [inline]
RIP: 0010:[<ffffffff8122a385>]  [<ffffffff8122a385>] arch_local_irq_save arch/x86/include/asm/paravirt.h:829 [inline]
RIP: 0010:[<ffffffff8122a385>]  [<ffffffff8122a385>] lock_is_held+0x55/0x140 kernel/locking/lockdep.c:3626
RSP: 0018:ffff8800adb3f958  EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff8801c88ce000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff81e6e89b RDI: ffff8801c88ce8dc
RBP: ffff8800adb3f978 R08: ffffffff83a44740 R09: ffffffff84a15338
R10: 0000000000000000 R11: 0000000000005c00 R12: ffff8801c88ce250
R13: ffffffff844bdba0 R14: ffffffff83a44740 R15: 0000000000000000
FS:  00007fa134bf3700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fde8839f140 CR3: 00000001d3932000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 0000000000000046 0000000000000003 ffff8801c88ce250 ffff8801c88ce260
 ffff8800adb3f990 ffffffff81277683 ffffffff84a15338 ffff8800adb3fa30
 ffffffff811e2635 ffffffff81224d1e ffffffff81224bc0 0000000000000046
Call Trace:
 [<ffffffff81277683>] rcu_read_lock_sched_held+0x103/0x120 kernel/rcu/update.c:108
 [<ffffffff811e2635>] trace_sched_load_avg_task include/trace/events/sched.h:651 [inline]
 [<ffffffff811e2635>] update_load_avg+0xc45/0x1850 kernel/sched/fair.c:3203
 [<ffffffff811e3867>] dequeue_entity kernel/sched/fair.c:3598 [inline]
 [<ffffffff811e3867>] dequeue_task_fair+0x1b7/0xa90 kernel/sched/fair.c:4775
 [<ffffffff811bbb45>] dequeue_task kernel/sched/core.c:866 [inline]
 [<ffffffff811bbb45>] deactivate_task+0xf5/0x2e0 kernel/sched/core.c:882
 [<ffffffff838b32ce>] __schedule+0xb4e/0x1d70 kernel/sched/core.c:3290
 [<ffffffff838b46ea>] schedule+0x7a/0x1b0 kernel/sched/core.c:3359
 [<ffffffff8125bd7e>] do_syslog+0x57e/0xb20 kernel/printk/printk.c:1327
 [<ffffffff8169b484>] kmsg_read+0x74/0xa0 fs/proc/kmsg.c:39
 [<ffffffff81671799>] proc_reg_read+0xf9/0x180 fs/proc/inode.c:202
 [<ffffffff8151c83c>] __vfs_read+0x11c/0x3e0 fs/read_write.c:432
 [<ffffffff8151e630>] vfs_read+0x130/0x360 fs/read_write.c:454
 [<ffffffff81520e39>] SYSC_read fs/read_write.c:569 [inline]
 [<ffffffff81520e39>] SyS_read+0xd9/0x1c0 fs/read_write.c:562
 [<ffffffff838c2725>] entry_SYSCALL_64_fastpath+0x22/0x9e
Code: c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 d8 00 00 00 8b 83 dc 08 00 00 85 c0 0f 85 ba 00 00 00 9c <58> 0f 1f 44 00 00 48 89 c3 fa 66 0f 1f 44 00 00 65 4c 8b 24 25 
NMI backtrace for cpu 1
CPU: 1 PID: 492 Comm: khungtaskd Not tainted 4.4.138-gcf21a9a #62
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800bb271800 task.stack: ffff8800bac80000
RIP: 0010:[<ffffffff810bfb26>]  [<ffffffff810bfb26>] native_apic_mem_write arch/x86/include/asm/apic.h:94 [inline]
RIP: 0010:[<ffffffff810bfb26>]  [<ffffffff810bfb26>] __default_send_IPI_dest_field arch/x86/include/asm/ipi.h:119 [inline]
RIP: 0010:[<ffffffff810bfb26>]  [<ffffffff810bfb26>] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:61 [inline]
RIP: 0010:[<ffffffff810bfb26>]  [<ffffffff810bfb26>] flat_send_IPI_mask+0xf6/0x1a0 arch/x86/kernel/apic/apic_flat_64.c:69
RSP: 0018:ffff8800bac87cc8  EFLAGS: 00000046
RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300
RBP: ffff8800bac87cf0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000246
R13: 0000000000000003 R14: 0000000000000002 R15: ffffffff8446f6a0
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fde8839f140 CR3: 00000001d3932000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff8446f6a0 ffffffff84a18ee0 0000000000000007 fffffbfff0942c8c
 0000000000000040 ffff8800bac87d10 ffffffff810b5ae1 ffffffff83c0b460
 0000000000000003 ffff8800bac87d68 ffffffff81e19d83 ffff8801c9064800
Call Trace:
 [<ffffffff810b5ae1>] nmi_raise_cpu_backtrace+0x61/0x80 arch/x86/kernel/apic/hw_nmi.c:33
 [<ffffffff81e19d83>] nmi_trigger_all_cpu_backtrace.cold.4+0x70/0xad lib/nmi_backtrace.c:85
 [<ffffffff810b5b84>] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 [<ffffffff8141a459>] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline]
 [<ffffffff8141a459>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8141a459>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8141a459>] watchdog.cold.1+0xd3/0xee kernel/hung_task.c:238
 [<ffffffff81190958>] kthread+0x268/0x300 kernel/kthread.c:211
 [<ffffffff838c2b55>] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:510
Code: b3 5f ff f6 c4 10 75 e2 44 89 e8 c1 e0 18 89 04 25 10 b3 5f ff 44 89 f2 09 da 80 cf 04 41 83 fe 02 0f 44 d3 89 14 25 00 b3 5f ff <41> f7 c4 00 02 00 00 75 1a 4c 89 e7 57 9d 0f 1f 44 00 00 e8 02