------------[ cut here ]------------ WARNING: CPU: 0 PID: 3030 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 lib/refcount.c:186 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 3030 Comm: syzkaller919576 Not tainted 4.13.0-rc6-next-20170825+ #9 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 panic+0x1e4/0x41c kernel/panic.c:181 __warn+0x1c4/0x1e0 kernel/panic.c:542 report_bug+0x211/0x2d0 lib/bug.c:183 fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:190 do_trap_no_signal arch/x86/kernel/traps.c:224 [inline] do_trap+0x260/0x390 arch/x86/kernel/traps.c:273 do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:310 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:323 invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:929 RIP: 0010:refcount_sub_and_test+0x167/0x1b0 lib/refcount.c:186 RSP: 0018:ffff88006bf76300 EFLAGS: 00010282 RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 RDX: 0000000000000026 RSI: 1ffff1000d7eec20 RDI: ffffed000d7eec54 RBP: ffff88006bf76390 R08: ffff88006bf759f0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1000d7eec61 R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff88006af27324 sctp_wfree+0x183/0x620 net/sctp/socket.c:7746 skb_release_head_state+0x124/0x200 net/core/skbuff.c:616 skb_release_all+0x15/0x60 net/core/skbuff.c:629 __kfree_skb net/core/skbuff.c:645 [inline] consume_skb+0x153/0x490 net/core/skbuff.c:705 sctp_chunk_destroy net/sctp/sm_make_chunk.c:1437 [inline] sctp_chunk_put+0x29c/0x420 net/sctp/sm_make_chunk.c:1464 sctp_chunk_free+0x53/0x60 net/sctp/sm_make_chunk.c:1451 __sctp_outq_teardown+0xc7d/0x15a0 net/sctp/outqueue.c:264 sctp_outq_free+0x15/0x20 net/sctp/outqueue.c:284 sctp_association_free+0x2d0/0x930 net/sctp/associola.c:357 sctp_cmd_delete_tcb net/sctp/sm_sideeffect.c:919 [inline] sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1333 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1200 [inline] sctp_do_sm+0x28e7/0x6dd0 net/sctp/sm_sideeffect.c:1171 sctp_primitive_SHUTDOWN+0xa0/0xd0 net/sctp/primitive.c:104 sctp_close+0x3c6/0x980 net/sctp/socket.c:1532 inet_release+0xed/0x1c0 net/ipv4/af_inet.c:425 inet6_release+0x50/0x70 net/ipv6/af_inet6.c:433 sock_release+0x8d/0x1e0 net/socket.c:597 sock_close+0x16/0x20 net/socket.c:1126 __fput+0x333/0x7f0 fs/file_table.c:210 ____fput+0x15/0x20 fs/file_table.c:246 task_work_run+0x199/0x270 kernel/task_work.c:112 exit_task_work include/linux/task_work.h:21 [inline] do_exit+0xa52/0x1b40 kernel/exit.c:865 do_group_exit+0x149/0x400 kernel/exit.c:968 get_signal+0x7e8/0x17e0 kernel/signal.c:2334 do_signal+0x94/0x1ee0 arch/x86/kernel/signal.c:808 exit_to_usermode_loop+0x224/0x300 arch/x86/entry/common.c:158 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath+0x42f/0x500 arch/x86/entry/common.c:266 entry_SYSCALL_64_fastpath+0xbc/0xbe RIP: 0033:0x43b279 RSP: 002b:00007f5cbc107db8 EFLAGS: 00000206 ORIG_RAX: 000000000000002c RAX: 0000000000000001 RBX: 0000000000000000 RCX: 000000000043b279 RDX: 0000000000000001 RSI: 0000000020018fff RDI: 0000000000000003 RBP: 0000000000000000 R08: 00000000206e4000 R09: 000000000000001c R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f5cbc1089c0 R15: 00007f5cbc108700 Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 86400 seconds..