BUG: unable to handle kernel NULL pointer dereference at 00000000000000fc
IP: qlist_free_all+0x37/0x160 mm/kasan/quarantine.c:163
PGD 1cad71067 P4D 1cad71067 PUD 1cad70067 PMD 0 
Oops: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 2378 Comm: udevd Not tainted 4.16.0+ #376
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:qlist_free_all+0x37/0x160 mm/kasan/quarantine.c:163
RSP: 0018:ffff8801cae5f9e0 EFLAGS: 00010246
RAX: ffff8801ca290d80 RBX: 0000000000000286 RCX: 0000000000000000
RDX: ffffea000728a400 RSI: dead0000000000ff RDI: 0000000000000286
RBP: ffff8801cae5fa18 R08: 1ffff100395cbf0a R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8801ca290d80 R15: ffffffff885127e0
FS:  00007fa6912d67a0(0000) GS:ffff8801db100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000fc CR3: 00000001cad67004 CR4: 00000000001606e0
DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 quarantine_reduce+0x141/0x170 mm/kasan/quarantine.c:259
 kasan_kmalloc+0xca/0xe0 mm/kasan/kasan.c:537
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489
 slab_post_alloc_hook mm/slab.h:443 [inline]
 slab_alloc mm/slab.c:3380 [inline]
 __do_kmalloc mm/slab.c:3704 [inline]
 __kmalloc+0x14b/0x760 mm/slab.c:3715
 kmalloc include/linux/slab.h:517 [inline]
 kernfs_fop_write+0x1ad/0x440 fs/kernfs/file.c:293
 __vfs_write+0xef/0x970 fs/read_write.c:480
 vfs_write+0x189/0x510 fs/read_write.c:544
 SYSC_write fs/read_write.c:589 [inline]
 SyS_write+0xef/0x220 fs/read_write.c:581
 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x7fa6909de370
RSP: 002b:00007ffe581b52e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000123c7a0 RCX: 00007fa6909de370
RDX: 0000000000000006 RSI: 000000000041f4f9 RDI: 000000000000000b
RBP: 000000000122e200 R08: 000000000041f4f1 R09: 00007fa690a347d0
R10: 7269762f73656369 R11: 0000000000000246 R12: 000000000000000b
R13: 0000000000000010 R14: 000000000123c790 R15: 0000000001223250
Code: 55 48 89 e5 41 57 41 56 41 55 41 54 49 c7 c7 e0 27 51 88 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 fc 00 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: ffff8801cae5f9e0
CR2: 00000000000000fc
---[ end trace 011ca865e4cbff2c ]---