INIT: Entering runlevel: 2 [info] Using makefile-style concurrent boot in runlevel 2. [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added 'ci-upstream-next-kasan-gce-7,10.128.0.9' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 37.148819] refcount_t: underflow; use-after-free. [ 37.149661] ------------[ cut here ]------------ [ 37.150558] WARNING: CPU: 1 PID: 3544 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 37.151785] Kernel panic - not syncing: panic_on_warn set ... [ 37.151785] [ 37.152879] CPU: 1 PID: 3544 Comm: syzkaller316831 Not tainted 4.13.0-rc5-next-20170817+ #5 [ 37.154006] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 37.155293] Call Trace: [ 37.155653] dump_stack+0x194/0x257 [ 37.156182] ? arch_local_irq_restore+0x53/0x53 [ 37.156817] panic+0x1e4/0x417 [ 37.157249] ? __warn+0x1d9/0x1d9 [ 37.157713] ? show_regs_print_info+0x65/0x65 [ 37.158325] ? refcount_sub_and_test+0x167/0x1b0 [ 37.158959] __warn+0x1c4/0x1d9 [ 37.159406] ? refcount_sub_and_test+0x167/0x1b0 [ 37.160084] report_bug+0x211/0x2d0 [ 37.160579] fixup_bug+0x40/0x90 [ 37.161034] do_trap+0x260/0x390 [ 37.161507] do_error_trap+0x120/0x390 [ 37.162052] ? do_trap+0x390/0x390 [ 37.162583] ? refcount_sub_and_test+0x167/0x1b0 [ 37.163266] ? vprintk_emit+0x3ea/0x590 [ 37.163851] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 37.164518] do_invalid_op+0x1b/0x20 [ 37.165020] invalid_op+0x18/0x20 [ 37.165484] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 37.166203] RSP: 0018:ffff8801c216e300 EFLAGS: 00010282 [ 37.167014] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 37.168004] RDX: 0000000000000026 RSI: 1ffff1003842dc20 RDI: ffffed003842dc54 [ 37.169137] RBP: ffff8801c216e390 R08: 0000000000000001 R09: 0000000000000000 [ 37.176381] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1003842dc61 [ 37.183706] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801dad6aa3c [ 37.190968] ? refcount_inc+0x50/0x50 [ 37.194734] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 37.199456] ? sctp_association_free+0x2d0/0x930 [ 37.204180] ? sctp_do_sm+0x28e7/0x6d90 [ 37.208120] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 37.212837] ? sctp_close+0x3c6/0x980 [ 37.216703] ? inet_release+0xed/0x1c0 [ 37.220560] sctp_wfree+0x183/0x620 [ 37.224242] ? __sctp_write_space+0x910/0x910 [ 37.228706] skb_release_head_state+0x124/0x200 [ 37.233436] skb_release_all+0x15/0x60 [ 37.237290] consume_skb+0x153/0x490 [ 37.240971] ? sctp_chunk_put+0x99/0x420 [ 37.244998] ? alloc_skb_with_frags+0x710/0x710 [ 37.249634] ? sctp_chunk_hold+0x20/0x20 [ 37.253667] ? refcount_sub_and_test+0x115/0x1b0 [ 37.258396] ? refcount_inc+0x50/0x50 [ 37.262164] ? mark_held_locks+0xaf/0x100 [ 37.266284] ? sctp_datamsg_put+0x456/0x560 [ 37.270583] sctp_chunk_put+0x29c/0x420 [ 37.275104] ? sctp_chunk_hold+0x20/0x20 [ 37.279137] ? sctp_transport_dst_confirm+0x50/0x50 [ 37.284126] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 37.289285] ? find_held_lock+0x35/0x1d0 [ 37.293334] sctp_chunk_free+0x53/0x60 [ 37.297189] __sctp_outq_teardown+0xc7d/0x15a0 [ 37.301747] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 37.306648] ? print_usage_bug+0x480/0x480 [ 37.310862] ? print_usage_bug+0x480/0x480 [ 37.315061] ? __free_insn_slot+0x5c0/0x5c0 [ 37.319352] ? unwind_dump+0x4c0/0x4c0 [ 37.323215] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 37.328376] ? is_bpf_text_address+0xa4/0x120 [ 37.332838] ? __kernel_text_address+0xae/0xe0 [ 37.337395] ? unwind_get_return_address+0x61/0xa0 [ 37.342295] ? check_noncircular+0x20/0x20 [ 37.346494] ? print_usage_bug+0x480/0x480 [ 37.350693] ? print_usage_bug+0x480/0x480 [ 37.354907] ? lock_acquire+0x1d5/0x580 [ 37.358851] ? lock_acquire+0x1d5/0x580 [ 37.362791] ? lock_timer_base+0x1a3/0x2b0 [ 37.367002] ? find_held_lock+0x35/0x1d0 [ 37.371039] ? sock_def_wakeup+0x1f9/0x350 [ 37.375241] ? lock_downgrade+0x990/0x990 [ 37.379360] ? lock_release+0xa40/0xa40 [ 37.383306] sctp_outq_free+0x15/0x20 [ 37.387162] sctp_association_free+0x2d0/0x930 [ 37.391713] ? sctp_asconf_queue_teardown+0x700/0x700 [ 37.396870] ? sock_def_wakeup+0x222/0x350 [ 37.401075] ? sk_dst_check+0x560/0x560 [ 37.405017] ? sctp_association_put+0x74/0x2f0 [ 37.409575] ? sctp_association_hold+0x20/0x20 [ 37.414128] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 37.419284] ? sctp_sm_lookup_event+0x95/0x3c0 [ 37.423844] sctp_do_sm+0x28e7/0x6d90 [ 37.427629] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 37.433665] ? lock_release+0xa40/0xa40 [ 37.437611] ? print_usage_bug+0x480/0x480 [ 37.441810] ? unwind_dump+0x4c0/0x4c0 [ 37.445665] ? print_usage_bug+0x480/0x480 [ 37.449871] ? is_bpf_text_address+0xa4/0x120 [ 37.454342] ? __kernel_text_address+0xae/0xe0 [ 37.458902] ? unwind_get_return_address+0x61/0xa0 [ 37.463799] ? find_held_lock+0x35/0x1d0 [ 37.467833] ? skb_dequeue+0x12a/0x180 [ 37.471686] ? lock_downgrade+0x990/0x990 [ 37.475806] ? do_raw_spin_trylock+0x190/0x190 [ 37.480358] ? mark_held_locks+0xaf/0x100 [ 37.484477] ? trace_hardirqs_on+0xd/0x10 [ 37.488602] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 37.493159] sctp_close+0x3c6/0x980 [ 37.496758] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 37.502001] ? lock_release+0xa40/0xa40 [ 37.505944] ? dentry_free+0xcd/0x130 [ 37.509728] ? rcu_read_lock_sched_held+0x108/0x120 [ 37.514716] ? kmem_cache_free+0x249/0x280 [ 37.518921] ? dentry_free+0xd2/0x130 [ 37.522693] ? ipv6_sock_ac_close+0x2e8/0x3e0 [ 37.527156] ? ipv6_sock_mc_close+0x148/0x1a0 [ 37.531617] ? ipv6_sock_ac_drop+0x580/0x580 [ 37.535996] ? ip_mc_drop_socket+0x1ce/0x230 [ 37.540382] ? __fsnotify_parent+0xb4/0x3a0 [ 37.544675] inet_release+0xed/0x1c0 [ 37.548366] inet6_release+0x50/0x70 [ 37.552051] sock_release+0x8d/0x1e0 [ 37.555735] ? sock_release+0x1e0/0x1e0 [ 37.559671] sock_close+0x16/0x20 [ 37.563177] __fput+0x327/0x7e0 [ 37.566437] ? fput+0x140/0x140 [ 37.569683] ? check_same_owner+0x320/0x320 [ 37.573968] ? _raw_spin_unlock_irq+0x27/0x70 [ 37.578439] ____fput+0x15/0x20 [ 37.581689] task_work_run+0x199/0x270 [ 37.585548] ? task_work_cancel+0x210/0x210 [ 37.589836] ? _raw_spin_unlock+0x22/0x30 [ 37.593949] ? switch_task_namespaces+0x87/0xc0 [ 37.598588] do_exit+0xa52/0x1b30 [ 37.602012] ? print_usage_bug+0x480/0x480 [ 37.606222] ? lock_release+0xa40/0xa40 [ 37.610165] ? mm_update_next_owner+0x930/0x930 [ 37.614801] ? check_noncircular+0x20/0x20 [ 37.619004] ? check_noncircular+0x20/0x20 [ 37.623209] ? find_held_lock+0x35/0x1d0 [ 37.627240] ? find_held_lock+0x35/0x1d0 [ 37.631277] ? check_noncircular+0x20/0x20 [ 37.635478] ? check_noncircular+0x20/0x20 [ 37.639677] ? lock_downgrade+0x990/0x990 [ 37.643801] ? do_raw_spin_trylock+0x190/0x190 [ 37.648353] ? reacquire_held_locks+0x1fd/0x3d0 [ 37.652986] ? mark_held_locks+0xaf/0x100 [ 37.657100] ? reacquire_held_locks+0x1fd/0x3d0 [ 37.661736] ? check_noncircular+0x20/0x20 [ 37.665938] ? find_held_lock+0x35/0x1d0 [ 37.669972] ? release_sock+0x1d4/0x2a0 [ 37.673913] ? lock_downgrade+0x990/0x990 [ 37.678027] ? lock_downgrade+0x990/0x990 [ 37.682155] ? find_held_lock+0x35/0x1d0 [ 37.686187] ? get_signal+0x855/0x17e0 [ 37.690042] ? lock_downgrade+0x990/0x990 [ 37.694169] do_group_exit+0x149/0x400 [ 37.698028] ? __lock_is_held+0xb6/0x140 [ 37.702060] ? SyS_exit+0x30/0x30 [ 37.705485] ? _raw_spin_unlock_irq+0x27/0x70 [ 37.709948] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 37.714937] get_signal+0x7e8/0x17e0 [ 37.718645] ? ptrace_notify+0x130/0x130 [ 37.722689] ? __local_bh_enable_ip+0x9d/0x160 [ 37.727248] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 37.732238] ? release_sock+0x1d4/0x2a0 [ 37.736184] ? trace_hardirqs_on+0xd/0x10 [ 37.740307] ? __local_bh_enable_ip+0x9d/0x160 [ 37.744861] ? _raw_spin_unlock_bh+0x30/0x40 [ 37.749256] ? release_sock+0x1d4/0x2a0 [ 37.753200] ? trace_hardirqs_on+0xd/0x10 [ 37.757323] do_signal+0x94/0x1ee0 [ 37.760836] ? inet_sendmsg+0x11f/0x5e0 [ 37.764773] ? inet_sendmsg+0x126/0x5e0 [ 37.768714] ? __might_sleep+0x95/0x190 [ 37.772656] ? setup_sigcontext+0x7d0/0x7d0 [ 37.776943] ? selinux_socket_sendmsg+0x36/0x40 [ 37.781582] ? security_socket_sendmsg+0x89/0xb0 [ 37.786311] ? inet_recvmsg+0x5f0/0x5f0 [ 37.790251] ? sock_sendmsg+0x4f/0x110 [ 37.794103] ? fput+0xd2/0x140 [ 37.797268] ? SYSC_sendto+0x40d/0x5a0 [ 37.801122] ? SYSC_connect+0x470/0x470 [ 37.805068] ? find_held_lock+0x35/0x1d0 [ 37.809105] ? exit_to_usermode_loop+0x98/0x300 [ 37.813751] exit_to_usermode_loop+0x224/0x300 [ 37.818304] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 37.823813] ? handle_mm_fault+0x4e3/0x940 [ 37.828012] ? down_read_trylock+0xdb/0x170 [ 37.832304] syscall_return_slowpath+0x42f/0x500 [ 37.837026] ? prepare_exit_to_usermode+0x2c0/0x2c0 [ 37.842008] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 37.846909] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 37.851976] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 37.856709] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 37.861430] RIP: 0033:0x4455a9 [ 37.864584] RSP: 002b:00007f0949bdbdb8 EFLAGS: 00000212 ORIG_RAX: 000000000000002c [ 37.872261] RAX: 0000000000000064 RBX: 0000000000000000 RCX: 00000000004455a9 [ 37.879498] RDX: 0000000000000064 RSI: 0000000020aa3000 RDI: 000000000000006f [ 37.886733] RBP: 0000000000000000 R08: 0000000020aa4fe4 R09: 000000000000001c [ 37.893973] R10: 0000000000000080 R11: 0000000000000212 R12: 0000000000000000 [ 37.901208] R13: 00007fff5f09991f R14: 00007f0949bdc9c0 R15: 0000000000000000 [ 37.908601] Dumping ftrace buffer: [ 37.912155] (ftrace buffer empty) [ 37.915838] Kernel Offset: disabled [ 37.919434] Rebooting in 86400 seconds..