INFO: task syz-executor7:5432 blocked for more than 120 seconds.
      Not tainted 4.4.110-gdac1439 #13
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7   D ffff8800b5dd7458 26424  5432   3580 0x20020004
 ffff8800b5dd7458 0000000000000024 3ae7aa741a4cbba4 ffff8800b5dd7500
 ffff8800b5dd7630 ffff8801d9c11b00 ffff8801db21fdb8 ffff8801db21fde0
 ffff8801db21f4d8 ffff8801d3300000 ffff8801d335af80 ffff8800b5dd0000
Call Trace:
 [<ffffffff837675ba>] schedule+0x9a/0x1c0 kernel/sched/core.c:3351
 [<ffffffff83772851>] schedule_timeout+0x3a1/0x970 kernel/time/timer.c:1508
 [<ffffffff8376553e>] io_schedule_timeout+0x1be/0x390 kernel/sched/core.c:4932
 [<ffffffff8376886b>] io_schedule include/linux/sched.h:447 [inline]
 [<ffffffff8376886b>] bit_wait_io+0x1b/0xc0 kernel/sched/wait.c:595
 [<ffffffff837683af>] __wait_on_bit_lock+0x8f/0x140 kernel/sched/wait.c:434
 [<ffffffff8141ca7d>] __lock_page+0x18d/0x1f0 mm/filemap.c:888
 [<ffffffff815b8ed0>] lock_page include/linux/pagemap.h:458 [inline]
 [<ffffffff815b8ed0>] __generic_file_splice_read+0x730/0xb00 fs/splice.c:412
 [<ffffffff815b9382>] generic_file_splice_read+0xe2/0x1c0 fs/splice.c:542
 [<ffffffff815b5685>] do_splice_to+0xf5/0x140 fs/splice.c:1154
 [<ffffffff815b5920>] splice_direct_to_actor+0x250/0x830 fs/splice.c:1226
 [<ffffffff815b60a7>] do_splice_direct+0x1a7/0x270 fs/splice.c:1337
 [<ffffffff8152006c>] do_sendfile+0x54c/0xd30 fs/read_write.c:1227
 [<ffffffff81522241>] C_SYSC_sendfile fs/read_write.c:1303 [inline]
 [<ffffffff81522241>] compat_SyS_sendfile+0xd1/0x160 fs/read_write.c:1292
 [<ffffffff81006d84>] do_syscall_32_irqs_on arch/x86/entry/common.c:390 [inline]
 [<ffffffff81006d84>] do_fast_syscall_32+0x314/0x890 arch/x86/entry/common.c:457
 [<ffffffff83776f6a>] sysenter_flags_fixed+0xd/0x17
no locks held by syz-executor7/5432.
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 486 Comm: khungtaskd Not tainted 4.4.110-gdac1439 #13
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800bb19df00 task.stack: ffff8800bb2d8000
RIP: 0010:[<ffffffff810c39c7>]  [<ffffffff810c39c7>] native_apic_mem_write arch/x86/include/asm/apic.h:94 [inline]
RIP: 0010:[<ffffffff810c39c7>]  [<ffffffff810c39c7>] __default_send_IPI_dest_field arch/x86/include/asm/ipi.h:119 [inline]
RIP: 0010:[<ffffffff810c39c7>]  [<ffffffff810c39c7>] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:61 [inline]
RIP: 0010:[<ffffffff810c39c7>]  [<ffffffff810c39c7>] flat_send_IPI_mask+0xf7/0x1a0 arch/x86/kernel/apic/apic_flat_64.c:69
RSP: 0018:ffff8800bb2dfcb8  EFLAGS: 00000046
RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300
RBP: ffff8800bb2dfce0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000246
R13: 0000000000000003 R14: ffffffff8426ea20 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 00000000b6a5c000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff8426ea20 ffffffff847ee1c0 000000000001bca0 0000000000000040
 dffffc0000000000 ffff8800bb2dfd00 ffffffff810b94fb ffffffff839f56a0
 0000000000000003 ffff8800bb2dfd60 ffffffff81d0fd97 0000000000000000
Call Trace:
 [<ffffffff810b94fb>] nmi_raise_cpu_backtrace+0x5b/0x70 arch/x86/kernel/apic/hw_nmi.c:33
 [<ffffffff81d0fd97>] nmi_trigger_all_cpu_backtrace+0x4a7/0x550 lib/nmi_backtrace.c:85
 [<ffffffff810b9594>] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 [<ffffffff81367b8a>] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline]
 [<ffffffff81367b8a>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81367b8a>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81367b8a>] watchdog+0x6fa/0xae0 kernel/hung_task.c:238
 [<ffffffff81190818>] kthread+0x268/0x300 kernel/kthread.c:211
 [<ffffffff837759df>] ret_from_fork+0x3f/0x70 arch/x86/entry/entry_64.S:494
Code: b3 5f ff f6 c4 10 75 e1 44 89 e8 c1 e0 18 89 04 25 10 b3 5f ff 44 89 fa 09 da 80 cf 04 41 83 ff 02 0f 44 d3 89 14 25 00 b3 5f ff <41> f7 c4 00 02 00 00 74 1a e8 5b 23 17 00 4c 89 e7 57 9d 0f 1f 
NMI backtrace for cpu 1
CPU: 1 PID: 3174 Comm: rsyslogd Not tainted 4.4.110-gdac1439 #13
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800b66d17c0 task.stack: ffff8800b65d0000
RIP: 0010:[<ffffffff811a4300>]  [<ffffffff811a4300>] __read_once_size include/linux/compiler.h:218 [inline]
RIP: 0010:[<ffffffff811a4300>]  [<ffffffff811a4300>] atomic_read arch/x86/include/asm/atomic.h:27 [inline]
RIP: 0010:[<ffffffff811a4300>]  [<ffffffff811a4300>] static_key_count include/linux/jump_label.h:172 [inline]
RIP: 0010:[<ffffffff811a4300>]  [<ffffffff811a4300>] static_key_false include/linux/jump_label.h:182 [inline]
RIP: 0010:[<ffffffff811a4300>]  [<ffffffff811a4300>] perf_event_task_sched_in include/linux/perf_event.h:931 [inline]
RIP: 0010:[<ffffffff811a4300>]  [<ffffffff811a4300>] finish_task_switch+0xf0/0x4e0 kernel/sched/core.c:2673
RSP: 0018:ffff8800b65d7a78  EFLAGS: 00000802
RAX: dffffc0000000000 RBX: ffff8801db31f4c0 RCX: 1ffffffff08fd409
RDX: 0000000000000000 RSI: ffffffff839fd820 RDI: ffffffff847ebdf8
RBP: ffff8800b65d7ac0 R08: ffff8800b65d0000 R09: 0000000000000002
R10: 0000000000000000 R11: 1ffff1003b476f6c R12: ffff8801da3a17c0
R13: ffff8801d4736d00 R14: 0000000000000000 R15: ffffffff847ea638
FS:  00007fa4f3846700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 00000000b6a5c000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 0000000000000046 ffffffff83766136 81c165dfdd4ca324 ffff8801db31f4d8
 ffff8801db31f4d8 ffff8801d4736d00 ffff8801d4736d00 ffff8801da3a1c00
 ffffffff847ea638 ffff8800b65d7b48 ffffffff837661ad ffff8800b65d7af8
Call Trace:
 [<ffffffff837661ad>] context_switch kernel/sched/core.c:2803 [inline]
 [<ffffffff837661ad>] __schedule+0xa9d/0x1c70 kernel/sched/core.c:3322
 [<ffffffff837675ba>] schedule+0x9a/0x1c0 kernel/sched/core.c:3351
 [<ffffffff81267d52>] do_syslog+0x592/0xae0 kernel/printk/printk.c:1327
 [<ffffffff8168ec84>] kmsg_read+0x74/0xa0 fs/proc/kmsg.c:39
 [<ffffffff81665aaf>] proc_reg_read+0xef/0x170 fs/proc/inode.c:202
 [<ffffffff8151c143>] __vfs_read+0x103/0x440 fs/read_write.c:432
 [<ffffffff8151dfe3>] vfs_read+0x123/0x3a0 fs/read_write.c:454
 [<ffffffff81520929>] SYSC_read fs/read_write.c:569 [inline]
 [<ffffffff81520929>] SyS_read+0xd9/0x1b0 fs/read_write.c:562
 [<ffffffff837755d9>] entry_SYSCALL_64_fastpath+0x16/0x92
Code: 03 80 3c 02 00 0f 85 c9 03 00 00 48 c7 c7 f8 bd 7e 84 4d 8b 34 24 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 <48> 89 f8 83 e0 07 83 c0 03 65 4c 8b 3c 25 00 67 01 00 38 d0 7c