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-mmots-kasan-gce-4,10.128.0.32' (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: [   33.617035] ------------[ cut here ]------------
[   33.617935] WARNING: CPU: 1 PID: 2994 at drivers/net/tun.c:1744 tun_get_user+0x2de3/0x36d0
[   33.619186] Kernel panic - not syncing: panic_on_warn set ...
[   33.619186] 
[   33.620161] CPU: 1 PID: 2994 Comm: syzkaller079888 Not tainted 4.14.0-rc5-mm1+ #20
[   33.621169] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   33.622389] Call Trace:
[   33.622750]  dump_stack+0x194/0x257
[   33.623242]  ? arch_local_irq_restore+0x53/0x53
[   33.623869]  ? vsnprintf+0x1ed/0x1900
[   33.624386]  panic+0x1e4/0x41c
[   33.624819]  ? refcount_error_report+0x214/0x214
[   33.625465]  ? show_regs_print_info+0x65/0x65
[   33.626069]  ? retint_kernel+0x10/0x10
[   33.626610]  ? __warn+0x1a9/0x1e0
[   33.627080]  ? tun_get_user+0x2de3/0x36d0
[   33.627636]  __warn+0x1c4/0x1e0
[   33.628082]  ? tun_get_user+0x2de3/0x36d0
[   33.628642]  report_bug+0x211/0x2d0
[   33.629169]  fixup_bug+0x40/0x90
[   33.629625]  do_trap+0x260/0x390
[   33.630089]  do_error_trap+0x120/0x390
[   33.630612]  ? kfree_skbmem+0xe2/0x1d0
[   33.631135]  ? do_trap+0x390/0x390
[   33.631612]  ? __mutex_unlock_slowpath+0xe9/0xac0
[   33.632257]  ? tun_get_user+0x2de3/0x36d0
[   33.632814]  ? wait_for_completion+0x770/0x770
[   33.633432]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   33.634098]  do_invalid_op+0x1b/0x20
[   33.634599]  invalid_op+0x18/0x20
[   33.635083] RIP: 0010:tun_get_user+0x2de3/0x36d0
[   33.635714] RSP: 0018:ffff8801d1ea7730 EFLAGS: 00010286
[   33.636437] RAX: dffffc0000000000 RBX: ffff8801d29ebbd8 RCX: dffffc0000000000
[   33.638932] RDX: ffffffff87024180 RSI: 0000000000000000 RDI: 0000000000000282
[   33.646168] RBP: ffff8801d1ea7ae0 R08: 0000000000000001 R09: 0000000000000000
[   33.653407] R10: ffffffff87069320 R11: 0000000000000000 R12: ffff8801d0c0d640
[   33.660649] R13: ffff8801d29ebc48 R14: 0000000000000003 R15: ffff8801d2908d40
[   33.667926]  ? tun_build_skb.isra.48+0x16e0/0x16e0
[   33.672822]  ? kmem_cache_alloc+0x12e/0x760
[   33.677113]  ? do_mmap+0x69b/0xd40
[   33.680620]  ? vm_mmap_pgoff+0x1de/0x280
[   33.684652]  ? SyS_mmap+0x16/0x20
[   33.688158]  ? entry_SYSCALL_64_fastpath+0x1f/0xbe
[   33.693069]  ? avc_has_extended_perms+0x12c0/0x12c0
[   33.698053]  ? check_noncircular+0x20/0x20
[   33.702268]  ? tun_get+0x1ab/0x2e0
[   33.705781]  ? lock_release+0xa40/0xa40
[   33.709726]  ? __lock_is_held+0xb6/0x140
[   33.713768]  ? tun_get+0x1d4/0x2e0
[   33.717274]  ? tun_chr_close+0x60/0x60
[   33.721128]  ? __check_object_size+0x25d/0x4f0
[   33.725683]  ? rcu_note_context_switch+0x710/0x710
[   33.730587]  tun_chr_write_iter+0xb9/0x160
[   33.734794]  do_iter_readv_writev+0x525/0x7f0
[   33.739260]  ? vfs_dedupe_file_range+0x8f0/0x8f0
[   33.743988]  ? rw_verify_area+0xe5/0x2b0
[   33.748021]  do_iter_write+0x154/0x540
[   33.751875]  ? dup_iter+0x260/0x260
[   33.755479]  vfs_writev+0x18a/0x340
[   33.759072]  ? __fget_light+0x297/0x380
[   33.763055]  ? vfs_iter_write+0xb0/0xb0
[   33.766997]  ? up_read+0x1a/0x40
[   33.770353]  ? __do_page_fault+0x3d6/0xd60
[   33.774555]  ? security_mmap_file+0x143/0x180
[   33.779027]  ? mm_fault_error+0x2c0/0x2c0
[   33.783149]  ? __fdget_pos+0x130/0x190
[   33.787013]  ? __fdget_raw+0x20/0x20
[   33.790695]  ? fget_raw+0x20/0x20
[   33.794114]  ? __do_page_fault+0xd60/0xd60
[   33.798322]  do_writev+0xfc/0x2a0
[   33.801742]  ? do_writev+0xfc/0x2a0
[   33.805339]  ? vfs_writev+0x340/0x340
[   33.809104]  ? entry_SYSCALL_64_fastpath+0x5/0xbe
[   33.813915]  ? trace_hardirqs_on_caller+0x421/0x5c0
[   33.818906]  SyS_writev+0x27/0x30
[   33.822327]  entry_SYSCALL_64_fastpath+0x1f/0xbe
[   33.827051] RIP: 0033:0x445080
[   33.830207] RSP: 002b:00007ffd3233bf28 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
[   33.837882] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000445080
[   33.845117] RDX: 0000000000000003 RSI: 00007ffd3233bf30 RDI: 0000000000000003
[   33.852353] RBP: 0000000000000082 R08: 0000000000000001 R09: 0000000000000002
[   33.859592] R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000402790
[   33.866829] R13: 0000000000402820 R14: 0000000000000000 R15: 0000000000000000
[   33.874219] Dumping ftrace buffer:
[   33.877767]    (ftrace buffer empty)
[   33.881444] Kernel Offset: disabled
[   33.885041] Rebooting in 86400 seconds..