pktgen: Cannot create thread for cpu 0 (-4)
pktgen: kernel_thread() failed for cpu 1
pktgen: Cannot create thread for cpu 1 (-4)
pktgen: Initialization failed for all threads
IPVS: stopping master sync thread 13560 ...
INFO: task syz-executor0:16609 blocked for more than 120 seconds.
      Not tainted 4.9.107-g42a730a #45
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D29816 16609  12592 0x00000004
 ffff880184023000 ffff880185af64c0 ffff8801c933d500 ffff880185379800
 ffff8801db321c18 ffff8801c750fb08 ffffffff839e8c1d 1ffff10038ea1f6e
 ffff8801d629c1f8 ffff8801c750fab8 00ffffff839eaa45 ffff8801db3224e8
Call Trace:
 [<ffffffff839ea21f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff839f5858>] __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:526 [inline]
 [<ffffffff839f5858>] rwsem_down_write_failed+0x598/0x990 kernel/locking/rwsem-xadd.c:555
 [<ffffffff81ee8587>] call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:105
 [<ffffffff839f362c>] __down_write arch/x86/include/asm/rwsem.h:125 [inline]
 [<ffffffff839f362c>] down_write+0x5c/0xa0 kernel/locking/rwsem.c:54
 [<ffffffff8156ab68>] inode_lock include/linux/fs.h:766 [inline]
 [<ffffffff8156ab68>] do_truncate2+0x128/0x1f0 fs/open.c:61
 [<ffffffff8156b7ee>] do_sys_ftruncate.constprop.16+0x3ce/0x4a0 fs/open.c:213
 [<ffffffff8156b9ac>] SYSC_ftruncate fs/open.c:223 [inline]
 [<ffffffff8156b9ac>] SyS_ftruncate+0x1c/0x30 fs/open.c:221
 [<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: [<ffffffff81366b6c>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff81366b6c>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff814261d0>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
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: [<ffffffff82120162>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2133
2 locks held by kworker/u4:4/4108:
 #0:  ("writeback"){++++.+}, at: [<ffffffff8118d02e>] work_static include/linux/workqueue.h:186 [inline]
 #0:  ("writeback"){++++.+}, at: [<ffffffff8118d02e>] set_work_data kernel/workqueue.c:617 [inline]
 #0:  ("writeback"){++++.+}, at: [<ffffffff8118d02e>] set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0:  ("writeback"){++++.+}, at: [<ffffffff8118d02e>] process_one_work+0x6ee/0x1500 kernel/workqueue.c:2085
 #1:  ((&(&wb->dwork)->work)){+.+.+.}, at: [<ffffffff8118d068>] process_one_work+0x728/0x1500 kernel/workqueue.c:2089
2 locks held by syz-executor0/16609:
 #0:  (sb_writers#13){.+.+.+}, at: [<ffffffff8156b62a>] sb_start_write include/linux/fs.h:1573 [inline]
 #0:  (sb_writers#13){.+.+.+}, at: [<ffffffff8156b62a>] do_sys_ftruncate.constprop.16+0x20a/0x4a0 fs/open.c:208
 #1:  (&sb->s_type->i_mutex_key#15){++++++}, at: [<ffffffff8156ab68>] inode_lock include/linux/fs.h:766 [inline]
 #1:  (&sb->s_type->i_mutex_key#15){++++++}, at: [<ffffffff8156ab68>] do_truncate2+0x128/0x1f0 fs/open.c:61

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

NMI backtrace for cpu 1
CPU: 1 PID: 519 Comm: khungtaskd Not tainted 4.9.107-g42a730a #45
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d8bafd08 ffffffff81eb42a9 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810b96a0 ffff8801d8bafd40
 ffffffff81ebf5a7 0000000000000001 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81eb42a9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb42a9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebf5a7>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebf53a>] 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
 [<ffffffff81367104>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81367104>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81367104>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81367104>] 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: 16603 Comm: syz-executor0 Not tainted 4.9.107-g42a730a #45
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff880184668000 task.stack: ffff8801cc210000
RIP: 0010:[<ffffffff8135ee9a>] 
c [<ffffffff8135ee9a>] check_kcov_mode kernel/kcov.c:66 [inline]
RIP: 0010:[<ffffffff8135ee9a>] 
c [<ffffffff8135ee9a>] __sanitizer_cov_trace_pc+0x1a/0x50 kernel/kcov.c:100
RSP: 0018:ffff8801cc2177c8  EFLAGS: 00000246
RAX: ffff880184668000 RBX: 0000000000000003 RCX: ffffc900012b6000
RDX: 0000000000000000 RSI: ffffffff81625789 RDI: ffffea00067d0440
RBP: ffff8801cc2177c8 R08: ffff880184668960 R09: 0000000000000001
R10: 0000000000000000 R11: 1ffff100308cd127 R12: ffffea00067d0440
R13: ffffea00067d0440 R14: 0000000000000200 R15: dffffc0000000000
FS:  00007f45aff0d700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c4491fd000 CR3: 00000001cd80a000 CR4: 00000000001606f0
DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Stack:
 ffff8801cc217868
c ffffffff816257ad
c ffff880184668962
c ffff8801d61c2848
c
 ffff880184668958
c ffffed003ac38509
c ffff880184668960
c ffff8801d61c2a00
c
 ffffea00067d0460
c 0000000000000008
c ffff8801d61c29d0
c 0000000841b58ab3
c
Call Trace:
 [<ffffffff816257ad>] constant_test_bit arch/x86/include/asm/bitops.h:311 [inline]
 [<ffffffff816257ad>] PagePrivate include/linux/page-flags.h:286 [inline]
 [<ffffffff816257ad>] grow_dev_page fs/buffer.c:1012 [inline]
 [<ffffffff816257ad>] grow_buffers fs/buffer.c:1078 [inline]
 [<ffffffff816257ad>] __getblk_slow fs/buffer.c:1105 [inline]
 [<ffffffff816257ad>] __getblk_gfp+0x2cd/0x710 fs/buffer.c:1386
 [<ffffffff8162900d>] __bread_gfp+0x2d/0x270 fs/buffer.c:1420
 [<ffffffff818cbf5b>] sb_bread include/linux/buffer_head.h:300 [inline]
 [<ffffffff818cbf5b>] __fat_write_inode+0x2ab/0x980 fs/fat/inode.c:844
 [<ffffffff818d0169>] fat_write_inode+0x79/0x170 fs/fat/inode.c:893
 [<ffffffff8160265d>] write_inode fs/fs-writeback.c:1180 [inline]
 [<ffffffff8160265d>] __writeback_single_inode+0x86d/0x1020 fs/fs-writeback.c:1379
 [<ffffffff816054af>] writeback_single_inode+0x24f/0x440 fs/fs-writeback.c:1433
 [<ffffffff8160577c>] sync_inode fs/fs-writeback.c:2458 [inline]
 [<ffffffff8160577c>] sync_inode_metadata+0xac/0xe0 fs/fs-writeback.c:2478
 [<ffffffff815f5211>] __generic_file_fsync+0x141/0x1a0 fs/libfs.c:985
 [<ffffffff815f52e7>] generic_file_fsync+0x77/0x110 fs/libfs.c:1011
 [<ffffffff818c7be7>] fat_file_fsync+0x77/0x170 fs/fat/file.c:165
 [<ffffffff8161ab1c>] vfs_fsync_range+0x10c/0x260 fs/sync.c:195
 [<ffffffff8143e262>] generic_write_sync include/linux/fs.h:2607 [inline]
 [<ffffffff8143e262>] generic_file_write_iter+0x442/0x610 mm/filemap.c:2897
 [<ffffffff8156efe0>] new_sync_write fs/read_write.c:496 [inline]
 [<ffffffff8156efe0>] __vfs_write+0x3e0/0x580 fs/read_write.c:509
 [<ffffffff81572dd7>] vfs_write+0x187/0x530 fs/read_write.c:557
 [<ffffffff81576c09>] SYSC_write fs/read_write.c:604 [inline]
 [<ffffffff81576c09>] SyS_write+0xd9/0x1c0 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
Code: 
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c