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-4,10.128.15.199' (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: [   41.107485] ------------[ cut here ]------------
[   41.108240] WARNING: CPU: 0 PID: 2986 at drivers/net/tun.c:1744 tun_get_user+0x2de3/0x36d0
[   41.109434] Kernel panic - not syncing: panic_on_warn set ...
[   41.109434] 
[   41.110406] CPU: 0 PID: 2986 Comm: syzkaller914043 Not tainted 4.14.0-rc4+ #80
[   41.111375] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   41.112600] Call Trace:
[   41.112963]  dump_stack+0x194/0x257
[   41.113457]  ? arch_local_irq_restore+0x53/0x53
[   41.114094]  panic+0x1e4/0x417
[   41.114529]  ? __warn+0x1d9/0x1d9
[   41.114996]  ? show_regs_print_info+0x65/0x65
[   41.115611]  ? tun_get_user+0x2de3/0x36d0
[   41.116167]  __warn+0x1c4/0x1d9
[   41.116614]  ? tun_get_user+0x2de3/0x36d0
[   41.117174]  report_bug+0x211/0x2d0
[   41.117671]  fixup_bug+0x40/0x90
[   41.118132]  do_trap+0x260/0x390
[   41.118599]  do_error_trap+0x120/0x390
[   41.119127]  ? kfree_skbmem+0xe2/0x1d0
[   41.119653]  ? do_trap+0x390/0x390
[   41.120132]  ? __mutex_unlock_slowpath+0xe9/0xac0
[   41.120778]  ? tun_get_user+0x2de3/0x36d0
[   41.121359]  ? wait_for_completion+0x7b0/0x7b0
[   41.121980]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   41.122632]  do_invalid_op+0x1b/0x20
[   41.123134]  invalid_op+0x18/0x20
[   41.123602] RIP: 0010:tun_get_user+0x2de3/0x36d0
[   41.124235] RSP: 0018:ffff8801ce42f730 EFLAGS: 00010286
[   41.124952] RAX: dffffc0000000000 RBX: ffff8801ce25fc98 RCX: dffffc0000000000
[   41.125906] RDX: ffffffff87062d20 RSI: 0000000000000000 RDI: ffffed0039c85ea8
[   41.126862] RBP: ffff8801ce42fae0 R08: 0000000000000090 R09: 0000000000000000
[   41.127822] R10: ffffffff870aaea0 R11: 0000000000000000 R12: ffff8801cf5a83c0
[   41.135062] R13: ffff8801ce25fd08 R14: 0000000000000000 R15: ffff8801ce1e8dc0
[   41.142340]  ? tun_build_skb.isra.48+0x16e0/0x16e0
[   41.147241]  ? mmap_region+0x7ee/0x15a0
[   41.151211]  ? tun_chr_close+0x60/0x60
[   41.155077]  ? lock_release+0xd70/0xd70
[   41.159024]  ? __lock_is_held+0xbc/0x140
[   41.163065]  ? tun_get+0x1d4/0x2e0
[   41.166575]  ? tun_chr_close+0x60/0x60
[   41.170430]  ? __check_object_size+0x25d/0x4f0
[   41.174988]  tun_chr_write_iter+0xbf/0x160
[   41.179194]  do_iter_readv_writev+0x531/0x7f0
[   41.183663]  ? vfs_dedupe_file_range+0x900/0x900
[   41.188393]  ? rw_verify_area+0xe5/0x2b0
[   41.192426]  do_iter_write+0x15a/0x540
[   41.196285]  ? dup_iter+0x260/0x260
[   41.199893]  vfs_writev+0x18a/0x340
[   41.203488]  ? __fget_light+0x29d/0x390
[   41.207436]  ? vfs_iter_write+0xb0/0xb0
[   41.211379]  ? up_read+0x1a/0x40
[   41.214714]  ? __do_page_fault+0x3d6/0xd60
[   41.218915]  ? security_mmap_file+0x143/0x180
[   41.223387]  ? mm_fault_error+0x2c0/0x2c0
[   41.227513]  ? __fdget_pos+0x136/0x1a0
[   41.231369]  ? __fdget_raw+0x20/0x20
[   41.235055]  ? __do_page_fault+0xd60/0xd60
[   41.239262]  do_writev+0xfc/0x2a0
[   41.242681]  ? do_writev+0xfc/0x2a0
[   41.246282]  ? vfs_writev+0x340/0x340
[   41.250049]  ? entry_SYSCALL_64_fastpath+0x5/0xbe
[   41.254861]  ? trace_hardirqs_on_caller+0x421/0x5c0
[   41.259850]  SyS_writev+0x27/0x30
[   41.263276]  entry_SYSCALL_64_fastpath+0x1f/0xbe
[   41.267998] RIP: 0033:0x4449e0
[   41.271157] RSP: 002b:00007fff5f3922a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
[   41.278834] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004449e0
[   41.286070] RDX: 0000000000000002 RSI: 00007fff5f3922b0 RDI: 0000000000000003
[   41.293310] RBP: 0000000000000086 R08: 0000000000000018 R09: 0000000000000004
[   41.300547] R10: 000000000007adef R11: 0000000000000246 R12: 00000000004020f0
[   41.307784] R13: 0000000000402180 R14: 0000000000000000 R15: 0000000000000000
[   41.315456] Dumping ftrace buffer:
[   41.318996]    (ftrace buffer empty)
[   41.322676] Kernel Offset: disabled
[   41.326279] Rebooting in 86400 seconds..