BUG: unable to handle kernel NULL pointer dereference at 000000004c8a7d7a
IP: qlist_free_all+0x37/0x160 mm/kasan/quarantine.c:163
PGD 1d0982067 P4D 1d0982067 PUD 1c355a067 PMD 0 
Oops: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 31720 Comm: syz-executor3 Not tainted 4.15.0-rc1+ #114
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: 000000007882ff82 task.stack: 00000000c5a2b70b
RIP: 0010:qlist_free_all+0x37/0x160 mm/kasan/quarantine.c:163
RSP: 0018:ffff8801c3b0f490 EFLAGS: 00010246
RAX: ffff8801c0d01ac0 RBX: 0000000000000286 RCX: 0000000000000000
RDX: ffffea0007034040 RSI: ffffffffffffffff RDI: 0000000000000286
RBP: ffff8801c3b0f4c8 R08: 1ffff10038761e60 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8801c0d01ac0 R15: ffffffff85ecb440
FS:  0000000000000000(0000) GS:ffff8801db400000(0063) knlGS:00000000f773eb40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000000000104 CR3: 00000001c51a2000 CR4: 00000000001406f0
DR0: 0000000020001000 DR1: 0000000020000000 DR2: 0000000020001000
DR3: 0000000020000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 quarantine_reduce+0x141/0x170 mm/kasan/quarantine.c:259
 kasan_kmalloc+0xca/0xe0 mm/kasan/kasan.c:536
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489
 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3547
 kmem_cache_zalloc include/linux/slab.h:678 [inline]
 __kernfs_new_node+0xe2/0x570 fs/kernfs/dir.c:633
 kernfs_new_node+0x80/0xe0 fs/kernfs/dir.c:679
 __kernfs_create_file+0x4b/0x320 fs/kernfs/file.c:989
 sysfs_add_file_mode_ns+0x220/0x510 fs/sysfs/file.c:307
 create_files fs/sysfs/group.c:64 [inline]
 internal_create_group+0x238/0x8d0 fs/sysfs/group.c:134
 sysfs_create_group fs/sysfs/group.c:156 [inline]
 sysfs_create_groups+0x97/0x140 fs/sysfs/group.c:183
 device_add_groups drivers/base/core.c:1024 [inline]
 device_add_attrs drivers/base/core.c:1172 [inline]
 device_add+0x7de/0x1640 drivers/base/core.c:1804
 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:2307 [inline]
 __tun_chr_ioctl+0x1d7a/0x3dc0 drivers/net/tun.c:2512
 tun_chr_compat_ioctl+0x29/0x30 drivers/net/tun.c:2789
 C_SYSC_ioctl fs/compat_ioctl.c:1473 [inline]
 compat_SyS_ioctl+0x151/0x2a30 fs/compat_ioctl.c:1419
 do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline]
 do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389
 entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:125
RIP: 0023:0xf7f42c79
RSP: 002b:00000000f773e08c EFLAGS: 00000296 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000017 RCX: 00000000400454ca
RDX: 0000000020a5afd8 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Code: 55 48 89 e5 41 57 41 56 41 55 41 54 49 c7 c7 40 b4 ec 85 53 49 89 f4 48 83 ec 10 48 89 7d c8 4d 85 e4 4d 89 e5 0f 84 c8 00 00 00 <49> 63 95 04 01 00 00 4c 8b 30 48 29 d0 49 83 3f 00 48 89 c6 0f 
RIP: qlist_free_all+0x37/0x160 mm/kasan/quarantine.c:163 RSP: ffff8801c3b0f490
CR2: 0000000000000104
---[ end trace 02a8d418d38a450c ]---