R13: 00000000000001e4 R14: 00000000006f5e00 R15: 0000000000000007
------------[ cut here ]------------
kobject_add_internal failed for ppp0 (error: -12 parent: net)
WARNING: CPU: 0 PID: 9670 at lib/kobject.c:242 kobject_add_internal+0x42c/0xba0 lib/kobject.c:240
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 9670 Comm: syz-executor2 Not tainted 4.17.0-rc2+ #18
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 panic+0x22f/0x4de kernel/panic.c:184
 __warn.cold.8+0x163/0x1b3 kernel/panic.c:536
 report_bug+0x252/0x2d0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x1de/0x490 arch/x86/kernel/traps.c:296
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992
RIP: 0010:kobject_add_internal+0x42c/0xba0 lib/kobject.c:240
RSP: 0018:ffff88018b5f7240 EFLAGS: 00010282
RAX: 000000000000003d RBX: ffff88018b5fc6e8 RCX: ffffc900022a2000
RDX: 0000000000040000 RSI: ffffffff8160f4e1 RDI: ffff88018b5f6da0
RBP: ffff88018b5f7338 R08: ffff8801b36c0700 R09: 0000000000000006
R10: ffff8801b36c0700 R11: 0000000000000000 R12: 00000000fffffff4
R13: ffff8801d65ae680 R14: ffffffff884c5b40 R15: ffff8801d9bcaf00
 kobject_add_varg lib/kobject.c:364 [inline]
 kobject_add+0x13a/0x190 lib/kobject.c:408
 device_add+0x3a5/0x16d0 drivers/base/core.c:1796
 netdev_register_kobject+0x180/0x380 net/core/net-sysfs.c:1604
 register_netdevice+0x997/0x11c0 net/core/dev.c:7961
 ppp_unit_register drivers/net/ppp/ppp_generic.c:1010 [inline]
 ppp_dev_configure+0xa8b/0xe70 drivers/net/ppp/ppp_generic.c:1066
 ppp_create_interface drivers/net/ppp/ppp_generic.c:3030 [inline]
 ppp_unattached_ioctl drivers/net/ppp/ppp_generic.c:865 [inline]
 ppp_ioctl+0x1d0d/0x30b2 drivers/net/ppp/ppp_generic.c:601
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x1cf/0x16a0 fs/ioctl.c:684
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701
 __do_sys_ioctl fs/ioctl.c:708 [inline]
 __se_sys_ioctl fs/ioctl.c:706 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x455389
RSP: 002b:00007fe247a53c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fe247a546d4 RCX: 0000000000455389
RDX: 0000000020000180 RSI: 00000000c004743e RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014
R13: 00000000000001e4 R14: 00000000006f5e00 R15: 0000000000000007
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..