pktgen: kernel_thread() failed for cpu 0
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
INFO: task syz-executor4:17070 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-executor4   D29576 17070  29350 0x00000004
 ffff88019026e000 ffff8801c99c39c0 ffff8801cc904540 ffff880196416000
 ffff8801db321c18 ffff88018d207c10 ffffffff839e8c1d ffffffff81235b37
 0000000000000000 ffff88019026e8c0 0000000600000007 ffff8801db3224e8
Call Trace:
 [<ffffffff839ea21f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff839f4644>] rwsem_down_read_failed+0x1e4/0x320 kernel/locking/rwsem-xadd.c:260
 [<ffffffff81ee8558>] call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94
 [<ffffffff839f3572>] __down_read arch/x86/include/asm/rwsem.h:65 [inline]
 [<ffffffff839f3572>] down_read+0x52/0xb0 kernel/locking/rwsem.c:24
 [<ffffffff8157d0e1>] iterate_supers+0xe1/0x260 fs/super.c:591
 [<ffffffff8161b122>] sys_sync+0xa2/0x170 fs/sync.c:112
 [<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/3768:
 #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
1 lock held by syz-executor4/17070:
 #0:  (&type->s_umount_key#48){++++..}, at: [<ffffffff8157d0e1>] iterate_supers+0xe1/0x260 fs/super.c:591
1 lock held by syz-executor4/17075:
 #0:  (&type->s_umount_key#48){++++..}, at: [<ffffffff8157d0e1>] iterate_supers+0xe1/0x260 fs/super.c:591

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

NMI backtrace for cpu 0
CPU: 0 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
 ffff8801d858fd08 ffffffff81eb42a9 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810b96a0 ffff8801d858fd40
 ffffffff81ebf5a7 0000000000000000 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 17020 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: ffff880196416000 task.stack: ffff8801bd998000
RIP: 0010:[<ffffffff810c2bfc>] 
c [<ffffffff810c2bfc>] native_apic_mem_write+0xc/0x10 arch/x86/include/asm/apic.h:98
RSP: 0018:ffff8801db307dc8  EFLAGS: 00000046
RAX: ffffffff810c2bf0 RBX: ffffffff84432860 RCX: 0000000000000020
RDX: 1ffffffff0886529 RSI: 00000000000000b7 RDI: 0000000000000380
RBP: ffff8801db307dc8 R08: ffff88021fffd058 R09: 000000000000000c
R10: ffffed0043fffa09 R11: 0000000000000001 R12: 00000000000000b7
R13: 1ffff1003b660fc0 R14: 0000000000000003 R15: ffff8801db307e60
FS:  00007feaf90b6700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb38c7f2000 CR3: 000000019ef29000 CR4: 00000000001606f0
DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Stack:
 ffff8801db307de8
c ffffffff810b13c0
c 0000000000000003
c ffff8801db3180c0
c
 ffff8801db307e88
c ffffffff812c72d4
c 00000000db307eb0
c 0000000041b58ab3
c
 ffffffff843bdda2
c ffffffff812c7020
c ffff8801db31c960
c 00000156ef90cee7
c
Call Trace:
 <IRQ> 
d [<ffffffff810b13c0>] apic_write arch/x86/include/asm/apic.h:398 [inline]
 <IRQ> 
d [<ffffffff810b13c0>] lapic_next_event+0x60/0x90 arch/x86/kernel/apic/apic.c:468
 [<ffffffff812c72d4>] clockevents_program_event+0x2b4/0x3e0 kernel/time/clockevents.c:339
 [<ffffffff812cbff4>] tick_program_event+0x104/0x190 kernel/time/tick-oneshot.c:47
 [<ffffffff812a60f1>] hrtimer_interrupt+0x1e1/0x430 kernel/time/hrtimer.c:1366
 [<ffffffff810b1e54>] local_apic_timer_interrupt+0x74/0xa0 arch/x86/kernel/apic/apic.c:935
 [<ffffffff839ff2dc>] smp_apic_timer_interrupt+0x7c/0xa0 arch/x86/kernel/apic/apic.c:959
 [<ffffffff839fb470>] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:648
 <EOI> 
d [<ffffffff81467a2b>] ? constant_test_bit arch/x86/include/asm/bitops.h:311 [inline]
 <EOI> 
d [<ffffffff81467a2b>] ? PageReferenced include/linux/page-flags.h:257 [inline]
 <EOI> 
d [<ffffffff81467a2b>] ? mark_page_accessed+0x2ab/0x610 mm/swap.c:383
 [<ffffffff8143a790>] pagecache_get_page+0x3a0/0x720 mm/filemap.c:1229
 [<ffffffff816242b2>] find_get_page_flags include/linux/pagemap.h:264 [inline]
 [<ffffffff816242b2>] __find_get_block_slow+0xc2/0x330 fs/buffer.c:212
 [<ffffffff8162485e>] __find_get_block+0x23e/0x4c0 fs/buffer.c:1360
 [<ffffffff81625669>] __getblk_slow fs/buffer.c:1101 [inline]
 [<ffffffff81625669>] __getblk_gfp+0x189/0x710 fs/buffer.c:1386
 [<ffffffff8162900d>] __bread_gfp+0x2d/0x270 fs/buffer.c:1420
 [<ffffffff818b7238>] sb_bread include/linux/buffer_head.h:300 [inline]
 [<ffffffff818b7238>] fat__get_entry+0x4c8/0x8f0 fs/fat/dir.c:100
 [<ffffffff818b9ec1>] fat_get_entry fs/fat/dir.c:128 [inline]
 [<ffffffff818b9ec1>] fat_get_short_entry+0x131/0x2a0 fs/fat/dir.c:876
 [<ffffffff818c1e27>] fat_subdirs+0xc7/0x190 fs/fat/dir.c:942
 [<ffffffff818d2139>] fat_read_root fs/fat/inode.c:1402 [inline]
 [<ffffffff818d2139>] fat_fill_super+0x1cf9/0x3550 fs/fat/inode.c:1832
 [<ffffffff818d8ef1>] vfat_fill_super+0x31/0x40 fs/fat/namei_vfat.c:1070
 [<ffffffff8157c857>] mount_bdev+0x2c7/0x390 fs/super.c:1100
 [<ffffffff818d8eb4>] vfat_mount+0x34/0x40 fs/fat/namei_vfat.c:1077
 [<ffffffff8157e5dc>] mount_fs+0x28c/0x370 fs/super.c:1206
 [<ffffffff815ddda1>] vfs_kern_mount.part.29+0xd1/0x3d0 fs/namespace.c:991
 [<ffffffff815e56c9>] vfs_kern_mount fs/namespace.c:973 [inline]
 [<ffffffff815e56c9>] do_new_mount fs/namespace.c:2513 [inline]
 [<ffffffff815e56c9>] do_mount+0x3c9/0x2740 fs/namespace.c:2835
 [<ffffffff815e841e>] SYSC_mount fs/namespace.c:3051 [inline]
 [<ffffffff815e841e>] SyS_mount+0xfe/0x110 fs/namespace.c:3028
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f9b13>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
c00 
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c48 
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c<5d> 
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c