TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies.  Check SNMP counters.
BUG: unable to handle kernel NULL pointer dereference at           (null)
IP:           (null)
PGD 35e8a067 P4D 35e8a067 PUD 8f245067 PMD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 23290 Comm: kworker/1:2 Not tainted 4.14.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: pencrypt padata_serial_worker
task: ffff8880a56982c0 task.stack: ffff88801e168000
RIP: 0010:          (null)
RSP: 0018:ffff88801e16fcc8 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff888057573350 RCX: 1ffff11003c2dfa1
RDX: 1ffff1100aeae662 RSI: 0000000000000000 RDI: ffff888057573300
RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000002
R10: 000000000011ce8a R11: ffff8880a56982c0 R12: 0000000000000001
R13: ffff88801e16fd08 R14: ffff888057573358 R15: ffff8880a5c06f00
FS:  0000000000000000(0000) GS:ffff8880aed00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000000d0ac000 CR4: 00000000001426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies.  Check SNMP counters.
Call Trace:
 padata_serial_worker+0x24e/0x3b0 kernel/padata.c:307
 process_one_work+0x7c0/0x14c0 kernel/workqueue.c:2116
==================================================================
BUG: KASAN: use-after-free in __list_add_valid+0x93/0xa0 lib/list_debug.c:26
Read of size 8 at addr ffff8880956041d0 by task syz-executor.2/28712
 worker_thread+0x5d7/0x1080 kernel/workqueue.c:2250

CPU: 0 PID: 28712 Comm: syz-executor.2 Not tainted 4.14.184-syzkaller #0
 kthread+0x30d/0x420 kernel/kthread.c:232
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x283 lib/dump_stack.c:58
Code: 
 Bad RIP value.
 print_address_description.cold+0x54/0x1dc mm/kasan/report.c:252
RIP:           (null) RSP: ffff88801e16fcc8
CR2: 0000000000000000
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0xa9/0x2b9 mm/kasan/report.c:393
---[ end trace 22836d00f8561feb ]---
 __list_add_valid+0x93/0xa0 lib/list_debug.c:26