INFO: task syz-executor.0:2111 blocked for more than 140 seconds.
      Not tainted 4.4.174+ #17
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D ffff8801c45679c8 24984  2111      1 0x20020004
 ffff8801c45679c8 ffff8801cff25f00 a869d6fc74a812c5 ffff8801cff25f00
 0000000000000000 ffff8801cff26700 ffff8801db71f180 ffff8801db71f1a8
 ffff8801db71e898 ffff8801d87cdf00 ffff8801cff25f00 ffffed00388ac001
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
 [<ffffffff81d46575>] lo_ioctl+0x85/0x1a70 drivers/block/loop.c:1416
 [<ffffffff81d4800d>] lo_compat_ioctl+0xad/0x140 drivers/block/loop.c:1618
 [<ffffffff81aa7200>] compat_blkdev_ioctl+0xca0/0x344f block/compat_ioctl.c:751
 [<ffffffff8159b2c3>] C_SYSC_ioctl fs/compat_ioctl.c:1592 [inline]
 [<ffffffff8159b2c3>] compat_SyS_ioctl+0x403/0x2210 fs/compat_ioctl.c:1544
 [<ffffffff8100603d>] do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline]
 [<ffffffff8100603d>] do_fast_syscall_32+0x32d/0xa90 arch/x86/entry/common.c:397
 [<ffffffff8271a350>] sysenter_flags_fixed+0xd/0x1a
1 lock held by syz-executor.0/2111:
 #0:  (loop_ctl_mutex/1){+.+.+.}, at: [<ffffffff81d46575>] lo_ioctl+0x85/0x1a70 drivers/block/loop.c:1416
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 12262 Comm: syz-executor.3 Not tainted 4.4.174+ #17
task: ffff8801b39817c0 task.stack: ffff8801b0cb0000
RIP: 0010:[<ffffffff81309601>]  [<ffffffff81309601>] preempt_count arch/x86/include/asm/preempt.h:22 [inline]
RIP: 0010:[<ffffffff81309601>]  [<ffffffff81309601>] check_kcov_mode kernel/kcov.c:66 [inline]
RIP: 0010:[<ffffffff81309601>]  [<ffffffff81309601>] __sanitizer_cov_trace_pc+0x11/0x50 kernel/kcov.c:100
RSP: 0018:ffff8801b0cb75c8  EFLAGS: 00000283
RAX: ffff8801b39817c0 RBX: 0000000000000038 RCX: ffffc90002f84000
RDX: 0000000000040000 RSI: ffffffff81aba4b4 RDI: ffff8801da002968
RBP: ffff8801b0cb75c8 R08: 0000000000000001 R09: ffff8801b39820d0
R10: ffffffff82836880 R11: 0000000000000000 R12: ffff8801da002b28
R13: 0040000000000000 R14: ffff8801da002940 R15: 0000000000000030
FS:  0000000000000000(0000) GS:ffff8801db600000(0063) knlGS:00000000f551bb40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 000000000248a308 CR3: 00000000b5354000 CR4: 00000000001606b0
Stack:
 ffff8801b0cb7648 ffffffff81aba4b4 0000000000000000 ffff8801b0cb76c8
 ffffed003b4005d8 ffff8801da002ec0 ffff8801b0cb76c0 0000000000000000
 0000000000000228 ffc0000000000000 ffff880100000000 0000000000000000
Call Trace:
 [<ffffffff81aba4b4>] radix_tree_next_chunk+0x444/0x730 lib/radix-tree.c:812
 [<ffffffff813bff4c>] find_get_entries+0x3ac/0x580 mm/filemap.c:1242
 [<ffffffff813e44ca>] pagevec_lookup_entries+0x3a/0x80 mm/swap.c:1083
 [<ffffffff813e5899>] truncate_inode_pages_range+0x1d9/0xde0 mm/truncate.c:257
 [<ffffffff813e64c5>] truncate_inode_pages+0x25/0x30 mm/truncate.c:390
 [<ffffffff8154b885>] kill_bdev+0xc5/0xf0 fs/block_dev.c:82
 [<ffffffff81d3efeb>] loop_set_status+0x28b/0x1260 drivers/block/loop.c:1128
 [<ffffffff81d40072>] loop_set_status_compat+0xb2/0x110 drivers/block/loop.c:1572
 [<ffffffff81d48070>] lo_compat_ioctl+0x110/0x140 drivers/block/loop.c:1600
 [<ffffffff81aa7200>] compat_blkdev_ioctl+0xca0/0x344f block/compat_ioctl.c:751
 [<ffffffff8159b2c3>] C_SYSC_ioctl fs/compat_ioctl.c:1592 [inline]
 [<ffffffff8159b2c3>] compat_SyS_ioctl+0x403/0x2210 fs/compat_ioctl.c:1544
 [<ffffffff8100603d>] do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline]
 [<ffffffff8100603d>] do_fast_syscall_32+0x32d/0xa90 arch/x86/entry/common.c:397
 [<ffffffff8271a350>] sysenter_flags_fixed+0xd/0x1a
Code: df e8 e4 b8 17 00 e9 ac fe ff ff 4c 89 f7 e8 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 
NMI backtrace for cpu 1
CPU: 1 PID: 20 Comm: khungtaskd Not tainted 4.4.174+ #17
task: ffff8801da6f17c0 task.stack: ffff8800001e0000
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:ffff8800001e7c88  EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fc300
RBP: ffff8800001e7cb8 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000246
R13: 0000000003000000 R14: ffffffff82e5f2e0 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe793f9a88 CR3: 00000000b9713000 CR4: 00000000001606b0
Stack:
 0000000000000001 ffffffff82e5f2e0 ffffffff831a6ac0 fffffbfff0634c34
 000000000001b6c0 0000000000000008 ffff8800001e7cd8 ffffffff81092bee
 0000000000000008 ffffffff82924260 ffff8800001e7d30 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