------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 8091 at lib/refcount.c:28 refcount_warn_saturate+0x165/0x1b0 lib/refcount.c:28
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 8091 Comm: syz-executor378 Not tainted 5.4.0-syzkaller #0
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+0x1fb/0x318 lib/dump_stack.c:118
 panic+0x264/0x7a9 kernel/panic.c:221
 __warn+0x20e/0x210 kernel/panic.c:582
 report_bug+0x1b6/0x2f0 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 do_error_trap+0xd7/0x440 arch/x86/kernel/traps.c:267
 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:refcount_warn_saturate+0x165/0x1b0 lib/refcount.c:28
Code: c7 28 7b c8 88 31 c0 e8 99 1b ba fd 0f 0b eb 83 e8 40 02 e8 fd c6 05 db 3e b1 05 01 48 c7 c7 54 7b c8 88 31 c0 e8 7b 1b ba fd <0f> 0b e9 62 ff ff ff e8 1f 02 e8 fd c6 05 bb 3e b1 05 01 48 c7 c7
RSP: 0018:ffff88809222f6a0 EFLAGS: 00010246
RAX: c3ab58b299cc6000 RBX: 0000000000000003 RCX: ffff888094fa62c0
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffff88809222f6b0 R08: ffffffff815fa274 R09: fffffbfff13c8332
R10: fffffbfff13c8332 R11: 0000000000000000 R12: 0000000000000900
R13: 00000000ffffff01 R14: 0000000000000003 R15: ffff8880a9ba6a04
 refcount_sub_and_test include/linux/refcount.h:261 [inline]
 sock_wfree+0x1d5/0x200 net/core/sock.c:1965
 sctp_wfree+0x3c7/0x740 net/sctp/socket.c:9113
 skb_release_head_state+0x100/0x210 net/core/skbuff.c:652
 skb_release_all net/core/skbuff.c:663 [inline]
 __kfree_skb+0x25/0x1c0 net/core/skbuff.c:679
 consume_skb+0x72/0x110 net/core/skbuff.c:838
 sctp_chunk_destroy net/sctp/sm_make_chunk.c:1454 [inline]
 sctp_chunk_put+0x17b/0x200 net/sctp/sm_make_chunk.c:1481
 sctp_chunk_free+0x59/0x60 net/sctp/sm_make_chunk.c:1468
 __sctp_outq_teardown+0x210/0xa30 net/sctp/outqueue.c:219
 sctp_outq_free+0x15/0x20 net/sctp/outqueue.c:276
 sctp_association_free+0x271/0x870 net/sctp/associola.c:339
 sctp_cmd_delete_tcb net/sctp/sm_sideeffect.c:934 [inline]
 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1322 [inline]
 sctp_side_effects net/sctp/sm_sideeffect.c:1189 [inline]
 sctp_do_sm+0x3e98/0x5730 net/sctp/sm_sideeffect.c:1160
 sctp_primitive_ABORT+0x99/0xd0 net/sctp/primitive.c:104
 sctp_close+0x277/0x7e0 net/sctp/socket.c:1513
 inet_release+0x165/0x1c0 net/ipv4/af_inet.c:427
 __sock_release net/socket.c:591 [inline]
 sock_close+0xe1/0x260 net/socket.c:1269
 __fput+0x2e4/0x740 fs/file_table.c:280
 ____fput+0x15/0x20 fs/file_table.c:313
 task_work_run+0x17e/0x1b0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x5c4/0x2020 kernel/exit.c:797
 do_group_exit+0x15c/0x2b0 kernel/exit.c:895
 __do_sys_exit_group+0x17/0x20 kernel/exit.c:906
 __se_sys_exit_group+0x14/0x20 kernel/exit.c:904
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:904
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x43ef98
Code: Bad RIP value.
RSP: 002b:00007fff39bbc948 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ef98
RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000
RBP: 00000000004be7a8 R08: 00000000000000e7 R09: ffffffffffffffd0
R10: 000000002059aff8 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000006d01a0 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..