------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 1 PID: 16 at lib/refcount.c:187 refcount_sub_and_test_checked+0x2c9/0x310 lib/refcount.c:187
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 4.20.0-rc3+ #313
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x244/0x39d lib/dump_stack.c:113
 panic+0x2ad/0x55c kernel/panic.c:188
 __warn.cold.8+0x20/0x45 kernel/panic.c:540
 report_bug+0x254/0x2d0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:290
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:969
RIP: 0010:refcount_sub_and_test_checked+0x2c9/0x310 lib/refcount.c:187
Code: 89 de e8 8a 1c ed fd 84 db 74 07 31 db e9 4d ff ff ff e8 aa 1b ed fd 48 c7 c7 20 b2 60 88 c6 05 49 62 80 06 01 e8 f7 7b b6 fd <0f> 0b 31 db e9 2c ff ff ff 48 89 cf e8 26 6b 30 fe e9 41 fe ff ff
RSP: 0018:ffff8881d9b55e50 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000100 RSI: ffffffff8165eaf5 RDI: 0000000000000005
RBP: ffff8881d9b55f38 R08: ffff8881d9b4a440 R09: ffffed103b5e3ef8
R10: ffffed103b5e3ef8 R11: ffff8881daf1f7c7 R12: ffff8881d2a53a3c
R13: 00000000ffffcc01 R14: ffff8881d9b55f10 R15: ffff8881b2ba01c0
 sock_wfree+0xb8/0x180 net/core/sock.c:1821
 sctp_wfree+0x3a8/0xb40 net/sctp/socket.c:8586
 skb_release_head_state+0x15f/0x2e0 net/core/skbuff.c:612
 skb_release_all+0x15/0x60 net/core/skbuff.c:625
kobject: 'loop5' (00000000cc80bc05): kobject_uevent_env
 __kfree_skb net/core/skbuff.c:641 [inline]
 consume_skb+0x1ae/0x570 net/core/skbuff.c:701
kobject: 'loop5' (00000000cc80bc05): fill_kobj_path: path = '/devices/virtual/block/loop5'
kobject: 'loop0' (00000000ba669f82): kobject_uevent_env
 sctp_chunk_destroy net/sctp/sm_make_chunk.c:1462 [inline]
 sctp_chunk_put+0x2d4/0x450 net/sctp/sm_make_chunk.c:1489
kobject: 'loop0' (00000000ba669f82): fill_kobj_path: path = '/devices/virtual/block/loop0'
 sctp_datamsg_destroy net/sctp/chunk.c:128 [inline]
 sctp_datamsg_put+0x28b/0x620 net/sctp/chunk.c:145
kobject: 'loop4' (000000000eaba39c): kobject_uevent_env
 sctp_chunk_free+0x46/0x60 net/sctp/sm_make_chunk.c:1474
 __sctp_outq_teardown+0xa8e/0x11f0 net/sctp/outqueue.c:271
kobject: 'loop4' (000000000eaba39c): fill_kobj_path: path = '/devices/virtual/block/loop4'
kobject: 'loop3' (00000000847588c7): kobject_uevent_env
kobject: 'loop3' (00000000847588c7): fill_kobj_path: path = '/devices/virtual/block/loop3'
kobject: 'loop2' (000000007f7cf05d): kobject_uevent_env
 sctp_outq_free+0x15/0x20 net/sctp/outqueue.c:291
 sctp_association_free+0x2f0/0x972 net/sctp/associola.c:361
kobject: 'loop2' (000000007f7cf05d): fill_kobj_path: path = '/devices/virtual/block/loop2'
 sctp_cmd_delete_tcb net/sctp/sm_sideeffect.c:939 [inline]
 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1353 [inline]
 sctp_side_effects net/sctp/sm_sideeffect.c:1220 [inline]
 sctp_do_sm+0x4a32/0x7180 net/sctp/sm_sideeffect.c:1191
 sctp_assoc_bh_rcv+0x346/0x670 net/sctp/associola.c:1073
 sctp_inq_push+0x280/0x370 net/sctp/inqueue.c:95
 sctp_rcv+0x2e50/0x4170 net/sctp/input.c:271
 sctp6_rcv+0x15/0x30 net/sctp/ipv6.c:1064
 ip6_protocol_deliver_rcu+0x381/0x1950 net/ipv6/ip6_input.c:394
 ip6_input_finish+0x84/0x170 net/ipv6/ip6_input.c:434
 NF_HOOK include/linux/netfilter.h:289 [inline]
 ip6_input+0xe9/0x600 net/ipv6/ip6_input.c:443
 dst_input include/net/dst.h:450 [inline]
 ip6_rcv_finish+0x17a/0x330 net/ipv6/ip6_input.c:76
 NF_HOOK include/linux/netfilter.h:289 [inline]
 ipv6_rcv+0x115/0x640 net/ipv6/ip6_input.c:272
 __netif_receive_skb_one_core+0x14d/0x200 net/core/dev.c:4948
 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:5058
 process_backlog+0x24e/0x7a0 net/core/dev.c:5870
 napi_poll net/core/dev.c:6293 [inline]
 net_rx_action+0x7fa/0x19b0 net/core/dev.c:6359
 __do_softirq+0x308/0xb7e kernel/softirq.c:292
 run_ksoftirqd+0x5e/0x100 kernel/softirq.c:654
 smpboot_thread_fn+0x68b/0xa00 kernel/smpboot.c:164
 kthread+0x35a/0x440 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Kernel Offset: disabled
Rebooting in 86400 seconds..