INIT: Entering runlevel: 2

[info] Using makefile-style concurrent boot in runlevel 2.
[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

Warning: Permanently added 'ci-upstream-net-kasan-gce-8,10.128.0.46' (ECDSA) to the list of known hosts.
net.ipv6.conf.syz0.accept_dad = 0
net.ipv6.conf.syz0.router_solicitations = 0
executing program
syzkaller login: [   33.997572] ------------[ cut here ]------------
[   34.002488] WARNING: CPU: 1 PID: 2982 at drivers/net/tun.c:1744 tun_get_user+0x2de3/0x36d0
[   34.011098] Kernel panic - not syncing: panic_on_warn set ...
[   34.011098] 
[   34.018439] CPU: 1 PID: 2982 Comm: syzkaller365748 Not tainted 4.14.0-rc4+ #80
[   34.025766] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   34.035090] Call Trace:
[   34.037650]  dump_stack+0x194/0x257
[   34.041254]  ? arch_local_irq_restore+0x53/0x53
[   34.045904]  panic+0x1e4/0x417
[   34.049070]  ? __warn+0x1d9/0x1d9
[   34.052495]  ? show_regs_print_info+0x65/0x65
[   34.056975]  ? tun_get_user+0x2de3/0x36d0
[   34.061093]  __warn+0x1c4/0x1d9
[   34.064343]  ? tun_get_user+0x2de3/0x36d0
[   34.068464]  report_bug+0x211/0x2d0
[   34.072066]  fixup_bug+0x40/0x90
[   34.075404]  do_trap+0x260/0x390
[   34.078746]  do_error_trap+0x120/0x390
[   34.082606]  ? kfree_skbmem+0xe2/0x1d0
[   34.086471]  ? do_trap+0x390/0x390
[   34.089985]  ? __mutex_unlock_slowpath+0xe9/0xac0
[   34.094800]  ? tun_get_user+0x2de3/0x36d0
[   34.098920]  ? wait_for_completion+0x7b0/0x7b0
[   34.103481]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   34.108301]  do_invalid_op+0x1b/0x20
[   34.111985]  invalid_op+0x18/0x20
[   34.115409] RIP: 0010:tun_get_user+0x2de3/0x36d0
[   34.120133] RSP: 0018:ffff8801ce6af730 EFLAGS: 00010286
[   34.125469] RAX: dffffc0000000000 RBX: ffff8801ce23d698 RCX: dffffc0000000000
[   34.132708] RDX: ffffffff87062d20 RSI: 0000000000000000 RDI: ffffed0039cd5ea8
[   34.139946] RBP: ffff8801ce6afae0 R08: 0000000000000090 R09: 0000000000000000
[   34.147188] R10: ffffffff870aaea0 R11: 0000000000000000 R12: ffff8801cde45300
[   34.154427] R13: ffff8801ce23d708 R14: 0000000000000000 R15: ffff8801ce2e0dc0
[   34.161710]  ? tun_build_skb.isra.48+0x16e0/0x16e0
[   34.166614]  ? mmap_region+0x7ee/0x15a0
[   34.170589]  ? tun_chr_close+0x60/0x60
[   34.174463]  ? lock_release+0xd70/0xd70
[   34.178410]  ? __lock_is_held+0xbc/0x140
[   34.182452]  ? tun_get+0x1d4/0x2e0
[   34.185963]  ? tun_chr_close+0x60/0x60
[   34.189819]  ? __check_object_size+0x25d/0x4f0
[   34.194379]  tun_chr_write_iter+0xbf/0x160
[   34.198586]  do_iter_readv_writev+0x531/0x7f0
[   34.203056]  ? vfs_dedupe_file_range+0x900/0x900
[   34.207795]  ? rw_verify_area+0xe5/0x2b0
[   34.211832]  do_iter_write+0x15a/0x540
[   34.215688]  ? dup_iter+0x260/0x260
[   34.219294]  vfs_writev+0x18a/0x340
[   34.222888]  ? __fget_light+0x29d/0x390
[   34.226834]  ? vfs_iter_write+0xb0/0xb0
[   34.230778]  ? up_read+0x1a/0x40
[   34.234117]  ? __do_page_fault+0x3d6/0xd60
[   34.238320]  ? security_mmap_file+0x143/0x180
[   34.242791]  ? mm_fault_error+0x2c0/0x2c0
[   34.246917]  ? __fdget_pos+0x136/0x1a0
[   34.250775]  ? __fdget_raw+0x20/0x20
[   34.254459]  ? __do_page_fault+0xd60/0xd60
[   34.258676]  do_writev+0xfc/0x2a0
[   34.262100]  ? do_writev+0xfc/0x2a0
[   34.265702]  ? vfs_writev+0x340/0x340
[   34.269475]  ? entry_SYSCALL_64_fastpath+0x5/0xbe
[   34.274289]  ? trace_hardirqs_on_caller+0x421/0x5c0
[   34.279281]  SyS_writev+0x27/0x30
[   34.282710]  entry_SYSCALL_64_fastpath+0x1f/0xbe
[   34.287434] RIP: 0033:0x444bb0
[   34.290592] RSP: 002b:00007ffe306e3668 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
[   34.298271] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000444bb0
[   34.305512] RDX: 0000000000000002 RSI: 00007ffe306e3670 RDI: 0000000000000003
[   34.312753] RBP: 0000000000000086 R08: 0000000000000066 R09: 0000000000000004
[   34.319997] R10: 00000000bbbbbbbb R11: 0000000000000246 R12: 00000000004022c0
[   34.327234] R13: 0000000000402350 R14: 0000000000000000 R15: 0000000000000000
[   34.334939] Dumping ftrace buffer:
[   34.338517]    (ftrace buffer empty)
[   34.342201] Kernel Offset: disabled
[   34.345804] Rebooting in 86400 seconds..