BUG: unable to handle kernel NULL pointer dereference at 00000000000000fc
PGD 19fa21067 P4D 19fa21067 PUD 19fa22067 PMD 0 
Oops: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 20065 Comm: kworker/u4:0 Not tainted 4.16.0+ #10
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: krdsd rds_connect_worker
RIP: 0010:qlist_free_all+0x37/0x160 mm/kasan/quarantine.c:163
RSP: 0018:ffff880198517180 EFLAGS: 00010246
RAX: ffff8800323a3762 RBX: 0000000000000282 RCX: 0000000000000000
RDX: ffffea0000c8e8c0 RSI: ffffea0000c8e8df RDI: 0000000000000282
RBP: ffff8801985171b8 R08: ffff8801b544ee78 R09: 0000000000000006
R10: ffff8801b544e640 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8800323a3762 R15: ffffffff88d18760
FS:  0000000000000000(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000fc CR3: 000000019fa20000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 quarantine_reduce+0x141/0x170 mm/kasan/quarantine.c:259
 kasan_kmalloc+0x99/0xe0 mm/kasan/kasan.c:538
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
 slab_post_alloc_hook mm/slab.h:444 [inline]
 slab_alloc mm/slab.c:3392 [inline]
 kmem_cache_alloc+0x11b/0x760 mm/slab.c:3552
 sock_alloc_inode+0x6f/0x300 net/socket.c:243
 alloc_inode+0x63/0x190 fs/inode.c:209
 new_inode_pseudo+0x69/0x1a0 fs/inode.c:894
 sock_alloc+0x41/0x270 net/socket.c:564
 __sock_create+0x161/0x920 net/socket.c:1249
 sock_create_kern+0x3b/0x50 net/socket.c:1331
 rds_tcp_conn_path_connect+0x2a3/0x960 net/rds/tcp_connect.c:108
 rds_connect_worker+0x190/0x260 net/rds/threads.c:175
 process_one_work+0xc1e/0x1b50 kernel/workqueue.c:2145
 worker_thread+0x1cc/0x1440 kernel/workqueue.c:2279
 kthread+0x345/0x410 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:411
Code: 55 48 89 e5 41 57 49 c7 c7 60 87 d1 88 41 56 41 55 41 54 49 89 f4 53 48 83 ec 10 48 89 7d c8 4d 89 e5 4d 85 e4 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: ffff880198517180
CR2: 00000000000000fc
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