IPVS: Creating netns size=2552 id=13
INFO: task syz-executor0:11627 blocked for more than 120 seconds.
      Not tainted 4.4.124-g49632c6 #62
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D ffff8801d8f5fa80 29480 11627   3818 0x00000004
 ffff8801d8f5fa80 0000000000000246 0000000000000296 0000000041b58ab3
 ffffffff83fabb00 ffff8801db31fdb8 ffff8801db31fde0 ffff8801db31f4d8
 ffff8801db31f4c0 ffff8801d9440000 ffff8801d93b8000 0000000000000000
Call Trace:
 [<ffffffff8376b6aa>] schedule+0x7a/0x1b0 kernel/sched/core.c:3359
 [<ffffffff81c989e0>] blk_mq_freeze_queue_wait+0x120/0x240 block/blk-mq.c:95
 [<ffffffff81ca0f5d>] blk_freeze_queue block/blk-mq.c:112 [inline]
 [<ffffffff81ca0f5d>] blk_mq_freeze_queue+0x1d/0x20 block/blk-mq.c:121
 [<ffffffff82422e8f>] loop_switch drivers/block/loop.c:610 [inline]
 [<ffffffff82422e8f>] loop_change_fd drivers/block/loop.c:693 [inline]
 [<ffffffff82422e8f>] lo_ioctl+0xfef/0x19c0 drivers/block/loop.c:1354
 [<ffffffff81caeb5b>] __blkdev_driver_ioctl block/ioctl.c:288 [inline]
 [<ffffffff81caeb5b>] blkdev_ioctl+0x4ab/0x1990 block/ioctl.c:584
 [<ffffffff815d256e>] block_ioctl+0xde/0x120 fs/block_dev.c:1625
 [<ffffffff8155a58a>] vfs_ioctl fs/ioctl.c:43 [inline]
 [<ffffffff8155a58a>] do_vfs_ioctl+0x7aa/0xee0 fs/ioctl.c:607
 [<ffffffff8155ad4f>] SYSC_ioctl fs/ioctl.c:622 [inline]
 [<ffffffff8155ad4f>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:613
 [<ffffffff837797e5>] entry_SYSCALL_64_fastpath+0x22/0x9e
1 lock held by syz-executor0/11627:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff82421f2f>] lo_ioctl+0x8f/0x19c0 drivers/block/loop.c:1348
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.124-g49632c6 #62
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffffffff84217840 task.stack: ffffffff84200000
RIP: 0010:[<ffffffff812d5e8a>]  [<ffffffff812d5e8a>] tick_nohz_stop_idle+0x4a/0x70 kernel/time/tick-sched.c:461
RSP: 0018:ffffffff84207dd8  EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff8801db219c40 RCX: ffffffff812d5936
RDX: 1ffff1003b64339a RSI: ffff8801db219c40 RDI: ffff8801db219cd0
RBP: ffffffff84207de8 R08: ffff88021fffd018 R09: 0000000000000006
R10: ffffed0043fffa01 R11: 0000000000000000 R12: 00000038235fea82
R13: ffff8801db219cd0 R14: 00000038235fea82 R15: ffffffff84208000
FS:  0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7671dcb000 CR3: 00000000b69a0000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8801db219c40 ffff8801db219cb4 ffffffff84207e20 ffffffff812d809f
 ffffffff84207e10 dffffc0000000000 ffffffff847deac8 fffffbfff07088c0
 ffffffff847ece38 ffffffff84207ed0 ffffffff81221b75 fffffbfff08fd9d6
Call Trace:
 [<ffffffff812d809f>] tick_nohz_idle_exit+0x2cf/0x3d0 kernel/time/tick-sched.c:943
 [<ffffffff81221b75>] cpu_idle_loop kernel/sched/idle.c:267 [inline]
 [<ffffffff81221b75>] cpu_startup_entry+0x2a5/0x8f0 kernel/sched/idle.c:301
 [<ffffffff83766639>] rest_init+0x189/0x190 init/main.c:410
 [<ffffffff84823811>] start_kernel+0x6b9/0x6ee init/main.c:682
 [<ffffffff84822312>] x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:196
 [<ffffffff84822454>] x86_64_start_kernel+0x140/0x163 arch/x86/kernel/head64.c:185
Code: 89 c7 e8 0a fa ff ff 48 8d bb 90 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 04 02 84 c0 74 04 3c 03 7e 16 <c7> 83 90 00 00 00 00 00 00 00 31 ff e8 f5 e5 ef ff 5b 41 5c 5d 
NMI backtrace for cpu 1
CPU: 1 PID: 487 Comm: khungtaskd Not tainted 4.4.124-g49632c6 #62
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800bb333000 task.stack: ffff8801d8f90000
RIP: 0010:[<ffffffff810c3fa7>]  [<ffffffff810c3fa7>] native_apic_mem_write arch/x86/include/asm/apic.h:94 [inline]
RIP: 0010:[<ffffffff810c3fa7>]  [<ffffffff810c3fa7>] __default_send_IPI_dest_field arch/x86/include/asm/ipi.h:119 [inline]
RIP: 0010:[<ffffffff810c3fa7>]  [<ffffffff810c3fa7>] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:61 [inline]
RIP: 0010:[<ffffffff810c3fa7>]  [<ffffffff810c3fa7>] flat_send_IPI_mask+0xf7/0x1a0 arch/x86/kernel/apic/apic_flat_64.c:69
RSP: 0018:ffff8801d8f97cb8  EFLAGS: 00000046
RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300
RBP: ffff8801d8f97ce0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000246
R13: 0000000000000003 R14: ffffffff8426f5a0 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd7b5e0a000 CR3: 00000000b69a0000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff8426f5a0 ffffffff847f09c0 fffffbfff08fdbec dffffc0000000000
 ffff8801db31bca0 ffff8801d8f97d00 ffffffff810b9adb ffffffff839f6e40
 0000000000000003 ffff8801d8f97d60 ffffffff81d115a4 ffffffff8141b803
Call Trace:
 [<ffffffff810b9adb>] nmi_raise_cpu_backtrace+0x5b/0x70 arch/x86/kernel/apic/hw_nmi.c:33
 [<ffffffff81d115a4>] nmi_trigger_all_cpu_backtrace+0x4a4/0x550 lib/nmi_backtrace.c:85
 [<ffffffff810b9b74>] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 [<ffffffff8136944a>] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline]
 [<ffffffff8136944a>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8136944a>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8136944a>] watchdog+0x6fa/0xae0 kernel/hung_task.c:238
 [<ffffffff811909c8>] kthread+0x268/0x300 kernel/kthread.c:211
 [<ffffffff83779c15>] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:510
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 8b 31 17 00 4c 89 e7 57 9d 0f 1f