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
netlink: 4 bytes leftover after parsing attributes in process `syz-executor1'.
INFO: task syz-executor0:9482 blocked for more than 120 seconds.
      Not tainted 4.9.107-gdb2c520 #46
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D29816  9482   3888 0x00000004
 ffff88017ba98000 ffff8801d5cc5500 ffff8801d5cc5500 ffff8801cc5ac800
 ffff8801db221c18 ffff88017bacfce8 ffffffff839e8c1d ffff88017ba988c8
 ffffed002f753118 ffff88017ba98000 00fffc0000000000 ffff8801db2224e8
Call Trace:
 [<ffffffff839ea21f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff839eaba3>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3590
 [<ffffffff839ef026>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff839ef026>] mutex_lock_nested+0x326/0x870 kernel/locking/mutex.c:621
 [<ffffffff815d7fac>] __fdget_pos+0xac/0xd0 fs/file.c:781
 [<ffffffff8157669e>] fdget_pos include/linux/file.h:66 [inline]
 [<ffffffff8157669e>] SYSC_write fs/read_write.c:599 [inline]
 [<ffffffff8157669e>] SyS_write+0x7e/0x1c0 fs/read_write.c:596
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f9b13>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

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
2 locks held by getty/3774:
 #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-executor0/9482:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d7fac>] __fdget_pos+0xac/0xd0 fs/file.c:781
1 lock held by syz-executor0/9492:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d7fac>] __fdget_pos+0xac/0xd0 fs/file.c:781
1 lock held by syz-executor0/9510:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d7fac>] __fdget_pos+0xac/0xd0 fs/file.c:781

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

NMI backtrace for cpu 1
CPU: 1 PID: 519 Comm: khungtaskd Not tainted 4.9.107-gdb2c520 #46
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d8897d08 ffffffff81eb3da9 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810b96a0 ffff8801d8897d40
 ffffffff81ebf0a7 0000000000000001 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4193 Comm: kworker/u4:4 Not tainted 4.9.107-gdb2c520 #46
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: writeback wb_workfn
c (flush-7:0)
c
task: ffff8801cf804800 task.stack: ffff880182648000
RIP: 0010:[<ffffffff81f1b960>] 
c [<ffffffff81f1b960>] __this_cpu_preempt_check+0x0/0x20 lib/smp_processor_id.c:57
RSP: 0018:ffff88018264f588  EFLAGS: 00000093
RAX: ffff8801cf804800 RBX: 0000000000000004 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff81624176 RDI: ffffffff83cce920
RBP: ffff88018264f5d0 R08: ffff8801cf805160 R09: 0000000000000001
R10: 0000000000000000 R11: 1ffff10039f00a27 R12: ffff8801b674d1f8
R13: dffffc0000000000 R14: ffff8801b674d1f8 R15: 0000000000000004
FS:  0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000023f8710 CR3: 00000001ca6ca000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff81624185
c 000002000720ff80
c 0000000000000041
c ffff8801cbf68000
c
 0000000000000001
c ffffea000720ff9c
c ffffea000720ff80
c 0000000000000200
c
 dffffc0000000000
c ffff88018264f670
c ffffffff81625159
c ffffffff855f9570
c
Call Trace:
 [<ffffffff81625159>] __getblk_slow fs/buffer.c:1101 [inline]
 [<ffffffff81625159>] __getblk_gfp+0x189/0x710 fs/buffer.c:1386
 [<ffffffff81628afd>] __bread_gfp+0x2d/0x270 fs/buffer.c:1420
 [<ffffffff818cba4b>] sb_bread include/linux/buffer_head.h:300 [inline]
 [<ffffffff818cba4b>] __fat_write_inode+0x2ab/0x980 fs/fat/inode.c:844
 [<ffffffff818cfc59>] fat_write_inode+0x79/0x170 fs/fat/inode.c:893
 [<ffffffff8160214d>] write_inode fs/fs-writeback.c:1180 [inline]
 [<ffffffff8160214d>] __writeback_single_inode+0x86d/0x1020 fs/fs-writeback.c:1379
 [<ffffffff8160344c>] writeback_sb_inodes+0x4ac/0xe70 fs/fs-writeback.c:1584
 [<ffffffff81603f0b>] __writeback_inodes_wb+0xfb/0x1e0 fs/fs-writeback.c:1653
 [<ffffffff81604692>] wb_writeback+0x512/0xbd0 fs/fs-writeback.c:1762
 [<ffffffff8160dfc0>] wb_check_old_data_flush fs/fs-writeback.c:1877 [inline]
 [<ffffffff8160dfc0>] wb_do_writeback fs/fs-writeback.c:1901 [inline]
 [<ffffffff8160dfc0>] wb_workfn+0x850/0xdb0 fs/fs-writeback.c:1930
 [<ffffffff8118d121>] process_one_work+0x7e1/0x1500 kernel/workqueue.c:2092
 [<ffffffff8118df16>] worker_thread+0xd6/0x10a0 kernel/workqueue.c:2226
 [<ffffffff8119d04d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f9cdc>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Code: 
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c