------------[ cut here ]------------
kobject_add_internal failed for gre0 (error: -12 parent: net)
WARNING: CPU: 1 PID: 15003 at lib/kobject.c:244 kobject_add_internal+0x3f6/0xbc0 lib/kobject.c:242
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 15003 Comm: syz-executor7 Not tainted 4.15.0-rc3+ #219
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 panic+0x1e4/0x41c kernel/panic.c:183
 __warn+0x1dc/0x200 kernel/panic.c:547
 report_bug+0x211/0x2d0 lib/bug.c:184
 fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:177
 fixup_bug arch/x86/kernel/traps.c:246 [inline]
 do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:295
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
 invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:930
RIP: 0010:kobject_add_internal+0x3f6/0xbc0 lib/kobject.c:242
RSP: 0018:ffff8801c065f6f0 EFLAGS: 00010286
RAX: dffffc0000000008 RBX: ffff8801c0e63b28 RCX: ffffffff815a017e
RDX: 0000000000010000 RSI: ffffc9000190f000 RDI: 0000000000000246
RBP: ffff8801c065f7e8 R08: 1ffff100380cbe71 R09: 0000000000000000
R10: ffff8801d8236340 R11: 0000000000000000 R12: 1ffff100380cbee4
R13: 00000000fffffff4 R14: ffff8801d78bdc00 R15: ffffffff857e0d00
 kobject_add_varg lib/kobject.c:366 [inline]
 kobject_add+0x132/0x1f0 lib/kobject.c:411
 device_add+0x355/0x1640 drivers/base/core.c:1787
 netdev_register_kobject+0x183/0x360 net/core/net-sysfs.c:1604
 register_netdevice+0xb2b/0x1010 net/core/dev.c:7698
 tun_set_iff drivers/net/tun.c:2319 [inline]
 __tun_chr_ioctl+0x1d7a/0x3dc0 drivers/net/tun.c:2524
 tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:2773
 vfs_ioctl fs/ioctl.c:46 [inline]
 do_vfs_ioctl+0x1b1/0x1530 fs/ioctl.c:686
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452a39
RSP: 002b:00007ff8e4453c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ff8e4453aa0 RCX: 0000000000452a39
RDX: 000000002021c000 RSI: 00000000400454ca RDI: 0000000000000014
RBP: 00007ff8e4453a90 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000004b75fb
R13: 00007ff8e4453bc8 R14: 00000000004b75fb R15: 0000000000000000
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..