IPVS: Creating netns size=2536 id=131
INFO: task syz-executor3:27291 blocked for more than 120 seconds.
      Not tainted 4.9.107-gdb2c520 #49
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor3   D29424 27291   3877 0x20020004
 ffff8801cfae6000 0000000000000000 ffff8801852c1a40 ffff8801cfe00000
 ffff8801db321c18 ffff88018b43fb90 ffffffff839e8c1d 0000000000000002
 0000000041b58ab3 ffffffff843b9ea3 00ffffff81221500 ffff8801db3224e8
Call Trace:
 [<ffffffff839ea21f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff81e414a4>] blk_mq_freeze_queue_wait+0x114/0x230 block/blk-mq.c:75
 [<ffffffff81e4a79d>] blk_freeze_queue block/blk-mq.c:92 [inline]
 [<ffffffff81e4a79d>] blk_mq_freeze_queue+0x1d/0x20 block/blk-mq.c:101
 [<ffffffff825cae02>] loop_switch drivers/block/loop.c:599 [inline]
 [<ffffffff825cae02>] loop_change_fd drivers/block/loop.c:685 [inline]
 [<ffffffff825cae02>] lo_ioctl+0x722/0x1aa0 drivers/block/loop.c:1350
 [<ffffffff825cc232>] lo_compat_ioctl+0xb2/0x140 drivers/block/loop.c:1540
 [<ffffffff81ea5555>] compat_blkdev_ioctl+0x3a5/0x3ad0 block/compat_ioctl.c:751
 [<ffffffff8168e9f6>] C_SYSC_ioctl fs/compat_ioctl.c:1602 [inline]
 [<ffffffff8168e9f6>] compat_SyS_ioctl+0x126/0x1fe0 fs/compat_ioctl.c:1549
 [<ffffffff81006da7>] do_syscall_32_irqs_on arch/x86/entry/common.c:325 [inline]
 [<ffffffff81006da7>] do_fast_syscall_32+0x2f7/0x870 arch/x86/entry/common.c:387
 [<ffffffff839fb210>] entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137

Showing all locks held in the system:
2 locks held by khungtaskd/519:
 #0:  (rcu_read_lock){......}, at: [<ffffffff8136662c>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8136662c>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.?..}, at: [<ffffffff81425cb7>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3679:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d7fac>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/3775:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839f7cc2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<ffffffff8211fc62>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2133
1 lock held by syz-executor3/27291:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff825ca76b>] lo_ioctl+0x8b/0x1aa0 drivers/block/loop.c:1344

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 519 Comm: khungtaskd Not tainted 4.9.107-gdb2c520 #49
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d8677d08 ffffffff81eb3da9 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810b96a0 ffff8801d8677d40
 ffffffff81ebf0a7 0000000000000000 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81eb3da9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb3da9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebf0a7>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebf03a>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810b97a4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81366bc4>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81366bc4>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81366bc4>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81366bc4>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119d04d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f9cdc>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.9.107-gdb2c520 #49
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d9a6b000 task.stack: ffff8801d9a80000
RIP: 0010:[<ffffffff811d06e4>] 
c [<ffffffff811d06e4>] idle_cpu kernel/sched/core.c:3963 [inline]
RIP: 0010:[<ffffffff811d06e4>] 
c [<ffffffff811d06e4>] got_nohz_idle_kick kernel/sched/core.c:628 [inline]
RIP: 0010:[<ffffffff811d06e4>] 
c [<ffffffff811d06e4>] scheduler_ipi+0x334/0x4e0 kernel/sched/core.c:1829
RSP: 0018:ffff8801db307fa8  EFLAGS: 00000046
RAX: dffffc0000000000 RBX: 0000000000021c00 RCX: 1ffffffff0886481
RDX: 1ffff1003b66449d RSI: ffffffff81f1b80b RDI: ffff8801db3224f0
RBP: ffff8801db307fd0 R08: 0000000000000001 R09: 0000000000000008
R10: ffffed0043fffa09 R11: 0000000000000001 R12: ffff8801db321c00
R13: ffff8801db300000 R14: ffff8801d9a6b000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffdb9b77608 CR3: 00000001c7194000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8801d9a6b000
c ffffffff84432860
c 0000000000000000
c 0000000000000001
c
 ffffffff84c5e788
c ffff8801db307fe8
c ffffffff839fe29c
c ffffffff84c4e648
c
 ffff8801d9a87d98
c ffffffff839fbe10
c ffff8801d9a87ce8
c <EOI> 
c 0000000000000000
c
Call Trace:
 <IRQ> 
d [<ffffffff839fe29c>] __smp_reschedule_interrupt arch/x86/kernel/smp.c:262 [inline]
 <IRQ> 
d [<ffffffff839fe29c>] smp_reschedule_interrupt+0x6c/0x90 arch/x86/kernel/smp.c:269
 [<ffffffff839fbe10>] reschedule_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:671
 <EOI> 
d [<ffffffff839f8726>] ? native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:53
 [<ffffffff839f7d65>] arch_safe_halt arch/x86/include/asm/paravirt.h:104 [inline]
 [<ffffffff839f7d65>] default_idle+0x55/0x360 arch/x86/kernel/process.c:437
 [<ffffffff8106abb0>] arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:428
 [<ffffffff839f8b85>] default_idle_call+0x45/0x60 kernel/sched/idle.c:97
 [<ffffffff81223185>] cpuidle_idle_call kernel/sched/idle.c:155 [inline]
 [<ffffffff81223185>] cpu_idle_loop kernel/sched/idle.c:248 [inline]
 [<ffffffff81223185>] cpu_startup_entry+0x2b5/0x380 kernel/sched/idle.c:303
 [<ffffffff810aea78>] start_secondary+0x328/0x400 arch/x86/kernel/smpboot.c:257
Code: 
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c