net.ipv6.conf.syz0.accept_dad = 0
net.ipv6.conf.syz0.router_solicitations = 0
executing program
syzkaller login: [   23.118468] ------------[ cut here ]------------
[   23.125189] WARNING: CPU: 0 PID: 3008 at drivers/net/tun.c:1744 tun_get_user+0x2de3/0x36d0
[   23.126128] Kernel panic - not syncing: panic_on_warn set ...
[   23.126128] 
[   23.126810] CPU: 0 PID: 3008 Comm: syzkaller750906 Not tainted 4.14.0-rc5-next-20171018+ #8
[   23.127622] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
[   23.128364] Call Trace:
[   23.128630]  dump_stack+0x194/0x257
[   23.128970]  ? arch_local_irq_restore+0x53/0x53
[   23.129410]  ? vsnprintf+0x1ed/0x1900
[   23.129791]  panic+0x1e4/0x41c
[   23.130191]  ? refcount_error_report+0x214/0x214
[   23.130681]  ? show_regs_print_info+0x65/0x65
[   23.131143]  ? __warn+0x1a9/0x1e0
[   23.131494]  ? tun_get_user+0x2de3/0x36d0
[   23.131918]  __warn+0x1c4/0x1e0
[   23.132251]  ? tun_get_user+0x2de3/0x36d0
[   23.132680]  report_bug+0x211/0x2d0
[   23.133043]  fixup_bug+0x40/0x90
[   23.133399]  do_trap+0x260/0x390
[   23.133684]  do_error_trap+0x120/0x390
[   23.133921]  ? kfree_skbmem+0xe2/0x1d0
[   23.134201]  ? do_trap+0x390/0x390
[   23.134568]  ? __mutex_unlock_slowpath+0xe9/0xac0
[   23.135066]  ? tun_get_user+0x2de3/0x36d0
[   23.135501]  ? wait_for_completion+0x770/0x770
[   23.135967]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   23.136460]  do_invalid_op+0x1b/0x20
[   23.136865]  invalid_op+0x18/0x20
[   23.137227] RIP: 0010:tun_get_user+0x2de3/0x36d0
[   23.137701] RSP: 0018:ffff88003845f730 EFLAGS: 00010286
[   23.138234] RAX: dffffc0000000000 RBX: ffff88006ceee9d8 RCX: dffffc0000000000
[   23.138956] RDX: ffffffff87024140 RSI: 0000000000000000 RDI: 0000000000000282
[   23.139648] RBP: ffff88003845fae0 R08: 0000000000000001 R09: 0000000000000000
[   23.140375] R10: ffffffff870692e0 R11: 0000000000000000 R12: ffff88006a62aa40
[   23.141369] R13: ffff88006ceeea48 R14: 0000000000000000 R15: ffff880068b08b80
[   23.142113]  ? __thp_get_unmapped_area+0x130/0x130
[   23.142473]  ? tun_build_skb.isra.48+0x16e0/0x16e0
[   23.142800]  ? kmem_cache_alloc+0x12e/0x760
[   23.143102]  ? do_mmap+0x69b/0xd40
[   23.143343]  ? vm_mmap_pgoff+0x1de/0x280
[   23.143617]  ? SyS_mmap_pgoff+0x23b/0x5f0
[   23.143899]  ? SyS_mmap+0x16/0x20
[   23.144141]  ? entry_SYSCALL_64_fastpath+0x1f/0xbe
[   23.144477]  ? trace_hardirqs_on+0xd/0x10
[   23.145226]  ? check_noncircular+0x20/0x20
[   23.145587]  ? tun_get+0x1ab/0x2e0
[   23.145895]  ? lock_release+0xa40/0xa40
[   23.146203]  ? __lock_is_held+0xb6/0x140
[   23.146506]  ? tun_get+0x1d4/0x2e0
[   23.146763]  ? tun_chr_close+0x60/0x60
[   23.147024]  ? __check_object_size+0x25d/0x4f0
[   23.147377]  ? rcu_note_context_switch+0x710/0x710
[   23.147786]  tun_chr_write_iter+0xb9/0x160
[   23.148133]  do_iter_readv_writev+0x525/0x7f0
[   23.148483]  ? vfs_dedupe_file_range+0x8f0/0x8f0
[   23.148892]  ? rw_verify_area+0xe5/0x2b0
[   23.149219]  do_iter_write+0x154/0x540
[   23.149541]  ? dup_iter+0x260/0x260
[   23.149804]  ? handle_mm_fault+0x410/0x8d0
[   23.150106]  ? __do_page_fault+0x31e/0xd60
[   23.150379]  vfs_writev+0x18a/0x340
[   23.150607]  ? __fget_light+0x297/0x380
[   23.150848]  ? vfs_iter_write+0xb0/0xb0
[   23.151127]  ? __do_page_fault+0x3d6/0xd60
[   23.151458]  ? down_read_killable+0x180/0x180
[   23.151829]  ? mm_fault_error+0x2c0/0x2c0
[   23.152147]  ? vm_mmap_pgoff+0x13b/0x280
[   23.152474]  ? __fdget_pos+0x130/0x190
[   23.152774]  ? do_page_fault+0xee/0x720
[   23.153069]  ? __fdget_raw+0x20/0x20
[   23.153409]  ? __do_page_fault+0xd60/0xd60
[   23.153760]  do_writev+0xfc/0x2a0
[   23.154034]  ? do_writev+0xfc/0x2a0
[   23.154323]  ? vfs_writev+0x340/0x340
[   23.154629]  ? entry_SYSCALL_64_fastpath+0x5/0xbe
[   23.154983]  ? trace_hardirqs_on_caller+0x421/0x5c0
[   23.155327]  SyS_writev+0x27/0x30
[   23.155563]  entry_SYSCALL_64_fastpath+0x1f/0xbe
[   23.155916] RIP: 0033:0x439e67
[   23.156135] RSP: 002b:00007fff560f5598 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
[   23.156786] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000439e67
[   23.157423] RDX: 0000000000000002 RSI: 00007fff560f55b0 RDI: 0000000000000003
[   23.157959] RBP: 0000000000000082 R08: 0000000000000066 R09: 0000000000000004
[   23.158484] R10: 00000000bbbbbbbb R11: 0000000000000246 R12: 0000000000000000
[   23.159004] R13: 0000000000402480 R14: 0000000000402510 R15: 0000000000000000
[   23.160966] Dumping ftrace buffer:
[   23.161265]    (ftrace buffer empty)
[   23.161499] Kernel Offset: disabled
[   23.161722] Rebooting in 86400 seconds..