TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 0 PID: 1833 Comm: kworker/0:2 Not tainted 4.9.111-g03c70fe #10 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events p9_poll_workfn task: ffff8801ce254800 task.stack: ffff8801ce258000 RIP: 0010:[] [] __lock_acquire+0xa1b/0x4070 kernel/locking/lockdep.c:3224 RSP: 0018:ffff8801ce25f8e0 EFLAGS: 00010006 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000018 RBP: ffff8801ce25fa90 R08: 0000000000000001 R09: 0000000000000001 R10: ffff8801ce254800 R11: 0000000000000001 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000018 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fffdef5d418 CR3: 00000001c4ebf000 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: 0000000041b58ab3 ffff8801ce2550f0 0000000000000002 0000000000000001 0000000000000000 ffff8801ce255112 ffff8801ce25fad0 0000000000000046 ffff8801ce2550b4 0000000000000000 ffff8801ce25faf0 ffffffff812367c4 Call Trace: [] lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756 [] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:112 [inline] [] _raw_spin_lock_irqsave+0x4e/0x62 kernel/locking/spinlock.c:159 [] p9_conn_cancel+0xaa/0x4c0 net/9p/trans_fd.c:201 [] p9_poll_mux net/9p/trans_fd.c:630 [inline] [] p9_poll_workfn+0x222/0x330 net/9p/trans_fd.c:1097 [] process_one_work+0x7e1/0x1500 kernel/workqueue.c:2092 [] worker_thread+0xd6/0x10a0 kernel/workqueue.c:2226 [] kthread+0x26d/0x300 kernel/kthread.c:211 [] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373 Code: 25 28 00 00 00 0f 85 17 27 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f 85 51 27 00 00 49 81 3e a0 8c e9 84 0f 84 08 f7 RIP [] __lock_acquire+0xa1b/0x4070 kernel/locking/lockdep.c:3224 RSP ---[ end trace 687ceb7822fe78d5 ]---