ip6_tunnel: 6tnl0 xmit: Local address not yet configured!
ip6_tunnel: ip6tnl2 xmit: Local address not yet configured!
ip6_tunnel: ip6tnl1 xmit: Local address not yet configured!
ip6_tunnel: ip6tnl3 xmit: Local address not yet configured!
ip6_tunnel: 6tnl0 xmit: Local address not yet configured!
INFO: task kworker/u4:14:16785 blocked for more than 140 seconds.
      Not tainted 4.14.86+ #18
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:14   D26360 16785      2 0x80000000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 schedule+0x7f/0x1b0 kernel/sched/core.c:3490
 blk_queue_enter+0x3fc/0x510 block/blk-core.c:801
 generic_make_request+0x1b3/0x870 block/blk-core.c:2222
 submit_bio+0xa7/0x3a0 block/blk-core.c:2302
 submit_bh_wbc.isra.17+0x45f/0x5f0 fs/buffer.c:3144
 __block_write_full_page+0x4ee/0x980 fs/buffer.c:1826
 block_write_full_page+0x227/0x280 fs/buffer.c:3012
 __writepage+0x5f/0xc0 mm/page-writeback.c:2302
 write_cache_pages+0x518/0xe90 mm/page-writeback.c:2240
 generic_writepages+0xda/0x150 mm/page-writeback.c:2326
 do_writepages+0xe0/0x270 mm/page-writeback.c:2341
 __writeback_single_inode+0xd8/0x1020 fs/fs-writeback.c:1320
 writeback_sb_inodes+0x468/0xcd0 fs/fs-writeback.c:1584
 __writeback_inodes_wb+0xf8/0x1e0 fs/fs-writeback.c:1653
 wb_writeback+0x4ee/0xb90 fs/fs-writeback.c:1762
 wb_check_old_data_flush fs/fs-writeback.c:1875 [inline]
 wb_do_writeback fs/fs-writeback.c:1899 [inline]
 wb_workfn+0x85d/0xe00 fs/fs-writeback.c:1928
 process_one_work+0x86e/0x1670 kernel/workqueue.c:2114
 worker_thread+0xdc/0x1000 kernel/workqueue.c:2248
 kthread+0x348/0x420 kernel/kthread.c:232
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402
INFO: task syz-executor5:29737 blocked for more than 140 seconds.
      Not tainted 4.14.86+ #18
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor5   D27992 29737   1846 0x00000004
Call Trace:
 schedule+0x7f/0x1b0 kernel/sched/core.c:3490
 blk_mq_freeze_queue_wait+0xfd/0x210 block/blk-mq.c:154
 loop_set_status+0x1b2/0xf40 drivers/block/loop.c:1101
 loop_set_status64+0x8d/0xe0 drivers/block/loop.c:1287
 lo_ioctl+0x3cd/0x17d0 drivers/block/loop.c:1400
 __blkdev_driver_ioctl block/ioctl.c:297 [inline]
 blkdev_ioctl+0x57d/0x18c0 block/ioctl.c:594
 block_ioctl+0xd9/0x120 fs/block_dev.c:1873
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x1a0/0x1030 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7e/0xb0 fs/ioctl.c:692
 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x457569
RSP: 002b:00007f929de07c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569
RDX: 00000000200000c0 RSI: 0000000000004c04 RDI: 0000000000000007
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f929de086d4
R13: 00000000004c07a8 R14: 00000000004d10e8 R15: 00000000ffffffff
INFO: task syz-executor0:29738 blocked for more than 140 seconds.
      Not tainted 4.14.86+ #18
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D25960 29738   1845 0x00000004
Call Trace:
 schedule+0x7f/0x1b0 kernel/sched/core.c:3490
 io_schedule+0x1c/0x70 kernel/sched/core.c:5097
 wait_on_page_bit_common mm/filemap.c:1000 [inline]
 wait_on_page_bit+0x22b/0x2e0 mm/filemap.c:1033
 wait_on_page_writeback include/linux/pagemap.h:550 [inline]
 __filemap_fdatawait_range+0x184/0x260 mm/filemap.c:434
 file_write_and_wait_range+0xce/0x100 mm/filemap.c:657
 blkdev_fsync+0x62/0xb0 fs/block_dev.c:636
 vfs_fsync_range+0x105/0x260 fs/sync.c:196
 generic_write_sync include/linux/fs.h:2693 [inline]
 blkdev_write_iter+0x2e5/0x3d0 fs/block_dev.c:1908
 call_write_iter include/linux/fs.h:1784 [inline]
 do_iter_readv_writev+0x3a4/0x560 fs/read_write.c:678
 do_iter_write+0x156/0x530 fs/read_write.c:957
 vfs_iter_write+0x70/0xa0 fs/read_write.c:970
 iter_file_splice_write+0x5b4/0xab0 fs/splice.c:749
 do_splice_from fs/splice.c:851 [inline]
 direct_splice_actor+0x116/0x160 fs/splice.c:1018
 splice_direct_to_actor+0x28c/0x750 fs/splice.c:973
 do_splice_direct+0x17b/0x220 fs/splice.c:1061
 do_sendfile+0x4a1/0xb50 fs/read_write.c:1438
 SYSC_sendfile64 fs/read_write.c:1493 [inline]
 SyS_sendfile64+0xab/0x140 fs/read_write.c:1485
 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x457569
RSP: 002b:00007fca5ada7c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457569
RDX: 0000000020000240 RSI: 0000000000000005 RDI: 0000000000000004
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0020000102000007 R11: 0000000000000246 R12: 00007fca5ada86d4
R13: 00000000004c3c2a R14: 00000000004d6230 R15: 00000000ffffffff
INFO: task syz-executor0:29741 blocked for more than 140 seconds.
      Not tainted 4.14.86+ #18
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D28056 29741   1845 0x00000004
Call Trace:
 schedule+0x7f/0x1b0 kernel/sched/core.c:3490
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893
 lo_ioctl+0x85/0x17d0 drivers/block/loop.c:1373
 __blkdev_driver_ioctl block/ioctl.c:297 [inline]
 blkdev_ioctl+0x57d/0x18c0 block/ioctl.c:594
 block_ioctl+0xd9/0x120 fs/block_dev.c:1873
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x1a0/0x1030 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7e/0xb0 fs/ioctl.c:692
 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x457569
RSP: 002b:00007fca5ad65c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569
RDX: 000000000000000e RSI: 0000000000004c00 RDI: 0000000000000004
RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fca5ad666d4
R13: 00000000004c069f R14: 00000000004d0fc8 R15: 00000000ffffffff

Showing all locks held in the system:
1 lock held by khungtaskd/23:
 #0:  (tasklist_lock){.+.+}, at: [<ffffffff99604947>] debug_show_all_locks+0x74/0x20f kernel/locking/lockdep.c:4541
2 locks held by getty/1755:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff9a1407d0>] tty_ldisc_ref_wait+0x20/0x80 drivers/tty/tty_ldisc.c:275
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff9a13bc2f>] n_tty_read+0x1ff/0x1700 drivers/tty/n_tty.c:2156
3 locks held by kworker/u4:14/16785:
 #0:  ("writeback"){+.+.}, at: [<ffffffff99529534>] process_one_work+0x784/0x1670 kernel/workqueue.c:2085
 #1:  ((&(&wb->dwork)->work)){+.+.}, at: [<ffffffff9952956c>] process_one_work+0x7bc/0x1670 kernel/workqueue.c:2089
 #2:  (&type->s_umount_key#23){++++}, at: [<ffffffff999660ba>] trylock_super+0x1a/0xe0 fs/super.c:402
1 lock held by syz-executor5/29737:
 #0:  (&lo->lo_ctl_mutex/1){+.+.}, at: [<ffffffff9a1efec5>] lo_ioctl+0x85/0x17d0 drivers/block/loop.c:1373
1 lock held by syz-executor0/29741:
 #0:  (&lo->lo_ctl_mutex/1){+.+.}, at: [<ffffffff9a1efec5>] lo_ioctl+0x85/0x17d0 drivers/block/loop.c:1373

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

NMI backtrace for cpu 0
CPU: 0 PID: 23 Comm: khungtaskd Not tainted 4.14.86+ #18
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xb9/0x11b lib/dump_stack.c:53
 nmi_cpu_backtrace.cold.0+0x47/0x85 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x121/0x146 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline]
 watchdog+0x574/0xa70 kernel/hung_task.c:252
 kthread+0x348/0x420 kernel/kthread.c:232
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 13980 Comm: loop0 Not tainted 4.14.86+ #18
task: ffff88819f9f9780 task.stack: ffff88819f7d8000
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x9/0x60 kernel/kcov.c:60
RSP: 0018:ffff88819f7df240 EFLAGS: 00000246
RAX: ffff88819f9f9780 RBX: 0000000000000012 RCX: 1ffff11033f3f3f5
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000246
RBP: ffff88819f7df348 R08: 0000000000000000 R09: 0000000000000000
R10: ffff88819f9fa000 R11: 0000000000000001 R12: ffffea0005ca8680
R13: dffffc0000000000 R14: ffffea000588d940 R15: ffffea0005ca86a0
FS:  0000000000000000(0000) GS:ffff8881dbb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c4339c5d70 CR3: 000000015d626001 CR4: 00000000001606a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 __read_once_size include/linux/compiler.h:183 [inline]
 compound_head include/linux/page-flags.h:147 [inline]
 find_get_pages_range_tag+0x1f2/0x940 mm/filemap.c:1807
 pagevec_lookup_range_tag+0x3b/0x80 mm/swap.c:993
 mpage_prepare_extent_to_map+0x2f6/0xa40 fs/ext4/inode.c:2643
 ext4_writepages+0x10d9/0x3040 fs/ext4/inode.c:2882
 do_writepages+0xe0/0x270 mm/page-writeback.c:2341
 __filemap_fdatawrite_range+0x19e/0x270 mm/filemap.c:345
 filemap_write_and_wait_range+0x58/0xd0 mm/filemap.c:556
 __generic_file_write_iter+0x2bc/0x540 mm/filemap.c:3148
 ext4_file_write_iter+0x4f6/0xe20 fs/ext4/file.c:264
 call_write_iter include/linux/fs.h:1784 [inline]
 lo_rw_aio+0x97b/0x1050 drivers/block/loop.c:540
 do_req_filebacked drivers/block/loop.c:582 [inline]
 loop_handle_cmd drivers/block/loop.c:1737 [inline]
 loop_queue_work+0x14c9/0x1e9a drivers/block/loop.c:1751
 kthread_worker_fn+0x27e/0x6a0 kernel/kthread.c:642
 kthread+0x348/0x420 kernel/kthread.c:232
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402
Code: 00 e9 9f fe ff ff 4c 89 e7 e8 14 01 22 00 e9 2c fe ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 48 8b 04 25 c0 de 01 00 <48> 85 c0 74 1a 65 8b 15 9b f7 90 66 81 e2 00 01 1f 00 75 0b 8b