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-kasan-gce-8,10.128.15.217' (ECDSA) to the list of known hosts. 2017/09/08 21:21:15 parsed 1 programs 2017/09/08 21:21:15 executed programs: 0 2017/09/08 21:21:20 executed programs: 482 syzkaller login: [ 56.482696] refcount_t: underflow; use-after-free. [ 56.488377] ------------[ cut here ]------------ [ 56.494121] WARNING: CPU: 1 PID: 5112 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 56.504338] Kernel panic - not syncing: panic_on_warn set ... [ 56.504338] [ 56.511718] CPU: 1 PID: 5112 Comm: syz-executor2 Not tainted 4.13.0+ #74 [ 56.518557] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 56.527912] Call Trace: [ 56.530504] dump_stack+0x194/0x257 [ 56.534136] ? arch_local_irq_restore+0x53/0x53 [ 56.538823] panic+0x1e4/0x417 [ 56.542018] ? __warn+0x1d9/0x1d9 [ 56.545468] ? show_regs_print_info+0x65/0x65 [ 56.549972] ? retint_kernel+0x10/0x10 [ 56.553868] ? refcount_sub_and_test+0x167/0x1b0 [ 56.558624] __warn+0x1c4/0x1d9 [ 56.561906] ? refcount_sub_and_test+0x169/0x1b0 [ 56.566665] ? refcount_sub_and_test+0x167/0x1b0 [ 56.571423] report_bug+0x211/0x2d0 [ 56.575061] fixup_bug+0x40/0x90 [ 56.578434] do_trap+0x260/0x390 [ 56.581809] do_error_trap+0x120/0x390 [ 56.585748] ? do_trap+0x390/0x390 [ 56.589282] ? refcount_sub_and_test+0x167/0x1b0 [ 56.594035] ? vprintk_emit+0x3ea/0x590 [ 56.598026] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 56.602881] do_invalid_op+0x1b/0x20 [ 56.606590] invalid_op+0x18/0x20 [ 56.610036] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 56.615387] RSP: 0018:ffff8801c5d36300 EFLAGS: 00010282 [ 56.620751] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 56.628024] RDX: 0000000000000026 RSI: 1ffff10038ba6c20 RDI: ffffed0038ba6c54 [ 56.635305] RBP: ffff8801c5d36390 R08: ffff8801c5d359f0 R09: 0000000000000000 [ 56.642571] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff10038ba6c61 [ 56.649837] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801c5dcf6a4 [ 56.657144] ? refcount_inc+0x50/0x50 [ 56.660951] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 56.665711] ? sctp_association_free+0x2d0/0x930 [ 56.670471] ? sctp_do_sm+0x28e7/0x6dd0 [ 56.674452] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 56.679220] ? sctp_close+0x3c6/0x980 [ 56.683019] ? inet_release+0xed/0x1c0 [ 56.686915] sctp_wfree+0x183/0x620 [ 56.690550] ? __sctp_write_space+0x910/0x910 [ 56.695061] skb_release_head_state+0x124/0x200 [ 56.699738] skb_release_all+0x15/0x60 [ 56.703626] consume_skb+0x153/0x490 [ 56.707332] ? sctp_chunk_put+0x99/0x420 [ 56.711389] ? alloc_skb_with_frags+0x710/0x710 [ 56.716056] ? sctp_chunk_hold+0x20/0x20 [ 56.720119] ? refcount_sub_and_test+0x115/0x1b0 [ 56.724865] ? refcount_inc+0x50/0x50 [ 56.728660] ? mark_held_locks+0xb2/0x100 [ 56.732814] ? sctp_datamsg_put+0x456/0x560 [ 56.737154] sctp_chunk_put+0x29c/0x420 [ 56.741136] ? sctp_chunk_hold+0x20/0x20 [ 56.745356] ? sctp_transport_dst_confirm+0x50/0x50 [ 56.750368] sctp_chunk_free+0x53/0x60 [ 56.754238] __sctp_outq_teardown+0xc7d/0x15a0 [ 56.758795] ? inet6_release+0x50/0x70 [ 56.762661] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 56.767565] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 56.772559] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 56.777549] ? unwind_dump+0x4c0/0x4c0 [ 56.781408] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 56.786397] ? unwind_dump+0x4c0/0x4c0 [ 56.790286] ? check_noncircular+0x20/0x20 [ 56.794500] ? check_noncircular+0x20/0x20 [ 56.798705] ? unwind_get_return_address+0x61/0xa0 [ 56.803609] ? __save_stack_trace+0x61/0xd0 [ 56.807904] ? check_noncircular+0x20/0x20 [ 56.812117] ? print_usage_bug+0x480/0x480 [ 56.816331] ? find_held_lock+0x39/0x1d0 [ 56.820374] ? lock_downgrade+0x990/0x990 [ 56.824502] ? sk_dst_check+0x560/0x560 [ 56.828457] ? rcu_read_lock_sched_held+0x108/0x120 [ 56.833453] ? lock_release+0xd70/0xd70 [ 56.837409] sctp_outq_free+0x15/0x20 [ 56.841181] sctp_association_free+0x2d0/0x930 [ 56.845739] ? sctp_asconf_queue_teardown+0x700/0x700 [ 56.850903] ? sock_def_wakeup+0x222/0x350 [ 56.855111] ? sk_dst_check+0x560/0x560 [ 56.859062] ? sctp_association_put+0x74/0x2f0 [ 56.863622] ? sctp_association_hold+0x20/0x20 [ 56.868179] ? unwind_dump+0x4c0/0x4c0 [ 56.872052] ? sctp_sm_lookup_event+0x95/0x3c0 [ 56.876618] sctp_do_sm+0x28e7/0x6dd0 [ 56.880405] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 56.886440] ? print_usage_bug+0x480/0x480 [ 56.890647] ? __lock_acquire+0x20fd/0x4620 [ 56.894947] ? print_usage_bug+0x480/0x480 [ 56.899169] ? find_held_lock+0x39/0x1d0 [ 56.903233] ? lock_downgrade+0x990/0x990 [ 56.907382] ? skb_dequeue+0x22/0x180 [ 56.911165] ? do_raw_spin_trylock+0x190/0x190 [ 56.915736] ? mark_held_locks+0xb2/0x100 [ 56.919892] ? trace_hardirqs_on+0xd/0x10 [ 56.924037] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 56.928606] sctp_close+0x3c6/0x980 [ 56.932216] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 56.937467] ? unwind_get_return_address+0x61/0xa0 [ 56.942373] ? check_noncircular+0x20/0x20 [ 56.946588] ? depot_save_stack+0x12c/0x490 [ 56.950892] ? ipv6_sock_ac_close+0x2e8/0x3e0 [ 56.955364] ? ipv6_sock_mc_close+0x148/0x1a0 [ 56.959834] ? ipv6_sock_ac_drop+0x580/0x580 [ 56.964219] ? ip_mc_drop_socket+0x1ce/0x230 [ 56.968609] ? __fsnotify_parent+0xb4/0x3a0 [ 56.972932] inet_release+0xed/0x1c0 [ 56.976625] inet6_release+0x50/0x70 [ 56.980313] sock_release+0x8d/0x1e0 [ 56.983998] ? sock_release+0x1e0/0x1e0 [ 56.987948] sock_close+0x16/0x20 [ 56.991374] __fput+0x333/0x7f0 [ 56.994634] ? fput+0x140/0x140 [ 56.997888] ? _raw_spin_unlock_irq+0x27/0x70 [ 57.002361] ____fput+0x15/0x20 [ 57.005612] task_work_run+0x199/0x270 [ 57.009476] ? task_work_cancel+0x210/0x210 [ 57.013771] ? _raw_spin_unlock+0x22/0x30 [ 57.017893] ? switch_task_namespaces+0x87/0xc0 [ 57.022540] do_exit+0xa52/0x1b40 [ 57.025967] ? plist_check_list+0xa0/0xa0 [ 57.030101] ? plist_del+0x47b/0x990 [ 57.033786] ? mm_update_next_owner+0x930/0x930 [ 57.038519] ? plist_add+0x760/0x760 [ 57.042207] ? unwind_dump+0x4c0/0x4c0 [ 57.046078] ? check_same_owner+0x320/0x320 [ 57.050376] ? find_held_lock+0x39/0x1d0 [ 57.054415] ? check_noncircular+0x20/0x20 [ 57.058634] ? lock_downgrade+0x990/0x990 [ 57.062754] ? refill_pi_state_cache.part.6+0x2f0/0x2f0 [ 57.068106] ? find_held_lock+0x39/0x1d0 [ 57.072150] ? lock_downgrade+0x990/0x990 [ 57.076272] ? recalc_sigpending_tsk+0x117/0x150 [ 57.081001] ? recalc_sigpending+0x103/0x160 [ 57.085390] ? recalc_sigpending_tsk+0x150/0x150 [ 57.090119] ? get_signal+0x397/0x17e0 [ 57.093990] do_group_exit+0x149/0x400 [ 57.097875] ? __lock_is_held+0xbc/0x140 [ 57.101909] ? SyS_exit+0x30/0x30 [ 57.105335] ? _raw_spin_unlock_irq+0x27/0x70 [ 57.109804] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 57.114795] get_signal+0x7e8/0x17e0 [ 57.118507] ? ptrace_notify+0x130/0x130 [ 57.122553] ? get_unused_fd_flags+0x190/0x190 [ 57.127119] ? exit_robust_list+0x240/0x240 [ 57.131424] do_signal+0x94/0x1ee0 [ 57.134939] ? __fd_install+0x2f7/0x6a0 [ 57.138885] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 57.143614] ? get_unused_fd_flags+0x190/0x190 [ 57.148182] ? setup_sigcontext+0x7d0/0x7d0 [ 57.152488] ? copy_user_generic_unrolled+0x89/0xc0 [ 57.157480] ? _copy_to_user+0xa2/0xc0 [ 57.161355] ? fd_install+0x4d/0x60 [ 57.164951] ? fput+0xd2/0x140 [ 57.168125] ? SYSC_accept4+0x4f2/0x850 [ 57.172079] ? __release_sock+0x360/0x360 [ 57.176223] ? exit_to_usermode_loop+0x98/0x300 [ 57.180893] exit_to_usermode_loop+0x224/0x300 [ 57.185449] ? sctp_inet_listen+0x141/0x850 [ 57.189753] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 57.195268] ? sctp_transport_get_idx+0x70/0x70 [ 57.199923] syscall_return_slowpath+0x42f/0x500 [ 57.204654] ? prepare_exit_to_usermode+0x2c0/0x2c0 [ 57.209646] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 57.214638] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 57.219625] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 57.224361] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 57.229086] RIP: 0033:0x451e59 [ 57.232248] RSP: 002b:00007f5f8b2bbcf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 57.239932] RAX: fffffffffffffe00 RBX: 00000000007180d8 RCX: 0000000000451e59 [ 57.247178] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000007180d8 [ 57.254421] RBP: 00000000007180b0 R08: 0000000000000000 R09: 0000000000000000 [ 57.261662] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 57.268907] R13: 0000000000a6f7ef R14: 00007f5f8b2bc9c0 R15: 000000000000000c [ 57.276732] Dumping ftrace buffer: [ 57.280302] (ftrace buffer empty) [ 57.283982] Kernel Offset: disabled [ 57.287587] Rebooting in 86400 seconds..