pktgen: Cannot create thread for cpu 1 (-4)
pktgen: Initialization failed for all threads
INFO: task syz-executor3:7537 blocked for more than 120 seconds.
      Not tainted 4.9.106-g8b94b87 #43
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor3   D29576  7537   3884 0x00000004
 ffff8801d6f69800 ffff8801d6e60000 ffff8801c9dcf480 ffff8801ccc36000
 ffff8801db321c18 ffff8801d4bc7c10 ffffffff839e8c0d ffffffff81235b37
 0000000000000000 ffff8801d6f6a0c0 0000000600000007 ffff8801db3224e8
Call Trace:
 [<ffffffff839ea20f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff839f4634>] rwsem_down_read_failed+0x1e4/0x320 kernel/locking/rwsem-xadd.c:260
 [<ffffffff81ee84b8>] call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94
 [<ffffffff839f3562>] __down_read arch/x86/include/asm/rwsem.h:65 [inline]
 [<ffffffff839f3562>] down_read+0x52/0xb0 kernel/locking/rwsem.c:24
 [<ffffffff8157d071>] iterate_supers+0xe1/0x260 fs/super.c:591
 [<ffffffff8161b0b2>] 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/520:
 #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: [<ffffffff81426150>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
2 locks held by getty/3728:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839f7cb2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff821200c2>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2133
1 lock held by syz-executor3/7537:
 #0:  (&type->s_umount_key#58){.+.+..}, at: [<ffffffff8157d071>] iterate_supers+0xe1/0x260 fs/super.c:591
1 lock held by syz-executor3/7574:
 #0:  (&type->s_umount_key#58){.+.+..}, at: [<ffffffff8157d071>] iterate_supers+0xe1/0x260 fs/super.c:591

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

NMI backtrace for cpu 1
CPU: 1 PID: 520 Comm: khungtaskd Not tainted 4.9.106-g8b94b87 #43
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d85a7d08 ffffffff81eb4209 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810b96a0 ffff8801d85a7d40
 ffffffff81ebf507 0000000000000001 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81eb4209>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb4209>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebf507>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebf49a>] 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: 7520 Comm: syz-executor0 Not tainted 4.9.106-g8b94b87 #43
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801cf604800 task.stack: ffff8801c5508000
RIP: 0010:[<ffffffff8135eea6>] 
c [<ffffffff8135eea6>] __read_once_size include/linux/compiler.h:243 [inline]
RIP: 0010:[<ffffffff8135eea6>] 
c [<ffffffff8135eea6>] check_kcov_mode kernel/kcov.c:68 [inline]
RIP: 0010:[<ffffffff8135eea6>] 
c [<ffffffff8135eea6>] __sanitizer_cov_trace_pc+0x26/0x50 kernel/kcov.c:100
RSP: 0018:ffff8801c550f780  EFLAGS: 00000246
RAX: ffff8801cf604800 RBX: ffff8801d9c170c8 RCX: ffffc90011738000
RDX: 0000000000000002 RSI: ffffffff8143906a RDI: ffff8801cf604be4
RBP: ffff8801c550f780 R08: ffff8801cf605110 R09: 0000000000000001
R10: ffff8801cf604800 R11: 1ffff10039ec0a1d R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8801d9c170c8
FS:  00007f831e333700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c428ebb010 CR3: 00000001cfc9b000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8801c550f7e8
c ffffffff8143906a
c ffffffff81438f40
c ffffed0039ec0a18
c
 ffff8801cf6050c8
c 0000000000000062
c ffff8801d9c170d0
c 0000000000000000
c
 ffff8801d9c170c8
c 0000000000000001
c dffffc0000000000
c 0000000000000000
c
Call Trace:
 [<ffffffff8143906a>] rcu_lock_release include/linux/rcupdate.h:498 [inline]
 [<ffffffff8143906a>] rcu_read_unlock include/linux/rcupdate.h:931 [inline]
 [<ffffffff8143906a>] find_get_entry+0x12a/0x540 mm/filemap.c:1132
 [<ffffffff8143a3bb>] pagecache_get_page+0x4b/0x720 mm/filemap.c:1203
 [<ffffffff81624242>] find_get_page_flags include/linux/pagemap.h:264 [inline]
 [<ffffffff81624242>] __find_get_block_slow+0xc2/0x330 fs/buffer.c:212
 [<ffffffff816247ee>] __find_get_block+0x23e/0x4c0 fs/buffer.c:1360
 [<ffffffff816255f9>] __getblk_slow fs/buffer.c:1101 [inline]
 [<ffffffff816255f9>] __getblk_gfp+0x189/0x710 fs/buffer.c:1386
 [<ffffffff81628f9d>] __bread_gfp+0x2d/0x270 fs/buffer.c:1420
 [<ffffffff818e7696>] sb_bread include/linux/buffer_head.h:300 [inline]
 [<ffffffff818e7696>] isofs_fill_super+0x8a6/0x2480 fs/isofs/inode.c:617
 [<ffffffff8157c7e7>] mount_bdev+0x2c7/0x390 fs/super.c:1100
 [<ffffffff818e38a4>] isofs_mount+0x34/0x40 fs/isofs/inode.c:1509
 [<ffffffff8157e56c>] mount_fs+0x28c/0x370 fs/super.c:1206
 [<ffffffff815ddd31>] vfs_kern_mount.part.29+0xd1/0x3d0 fs/namespace.c:991
 [<ffffffff815e5659>] vfs_kern_mount fs/namespace.c:973 [inline]
 [<ffffffff815e5659>] do_new_mount fs/namespace.c:2513 [inline]
 [<ffffffff815e5659>] do_mount+0x3c9/0x2740 fs/namespace.c:2835
 [<ffffffff815e83ae>] SYSC_mount fs/namespace.c:3051 [inline]
 [<ffffffff815e83ae>] 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: 
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c00 
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c<83> 
cfa 
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c88 
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c12 
c00 
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c12 
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c11 
c