IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready
IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
INFO: task syz-executor0:4295 blocked for more than 140 seconds.
      Not tainted 4.9.111-g03c70fe #10
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D28912  4295   3919 0x20020004
 ffff8801cfbe3000 0000000000000000 ffff8801cee1c540 ffff8801d9a6b000
 ffff8801db321c18 ffff8801cef17b90 ffffffff839e7ded 0000000000000002
 0000000041b58ab3 ffffffff843bac1b 00ffffff81221510 ffff8801db3224e8
Call Trace:
 [<ffffffff839e93ef>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff81e3fe24>] blk_mq_freeze_queue_wait+0x114/0x230 block/blk-mq.c:75
 [<ffffffff81e4911d>] blk_freeze_queue block/blk-mq.c:92 [inline]
 [<ffffffff81e4911d>] blk_mq_freeze_queue+0x1d/0x20 block/blk-mq.c:101
 [<ffffffff825c98c2>] loop_switch drivers/block/loop.c:599 [inline]
 [<ffffffff825c98c2>] loop_change_fd drivers/block/loop.c:685 [inline]
 [<ffffffff825c98c2>] lo_ioctl+0x722/0x1aa0 drivers/block/loop.c:1350
 [<ffffffff825cacf2>] lo_compat_ioctl+0xb2/0x140 drivers/block/loop.c:1540
 [<ffffffff81ea3ed5>] compat_blkdev_ioctl+0x3a5/0x3ad0 block/compat_ioctl.c:751
 [<ffffffff8168eb56>] C_SYSC_ioctl fs/compat_ioctl.c:1602 [inline]
 [<ffffffff8168eb56>] 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
 [<ffffffff839fa3d0>] 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: [<ffffffff813666fc>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff813666fc>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81425d87>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3673:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d810c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/3769:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839f6e92>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8211e602>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2133
1 lock held by syz-executor0/4295:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff825c922b>] lo_ioctl+0x8b/0x1aa0 drivers/block/loop.c:1344
1 lock held by blkid/4296:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff825c922b>] lo_ioctl+0x8b/0x1aa0 drivers/block/loop.c:1344

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

NMI backtrace for cpu 1
CPU: 1 PID: 519 Comm: khungtaskd Not tainted 4.9.111-g03c70fe #10
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d961fd08 ffffffff81eb2729 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810b9af0 ffff8801d961fd40
 ffffffff81ebda27 0000000000000001 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81eb2729>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb2729>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebda27>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebd9ba>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810b9bf4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81366c94>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81366c94>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81366c94>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81366c94>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119d05d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f8e9c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff839f78f6