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-0,10.128.15.196' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 34.487204] refcount_t: underflow; use-after-free. [ 34.492253] ------------[ cut here ]------------ [ 34.497158] WARNING: CPU: 0 PID: 3045 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 34.505825] Kernel panic - not syncing: panic_on_warn set ... [ 34.505825] [ 34.513161] CPU: 0 PID: 3045 Comm: syzkaller577266 Not tainted 4.13.0-rc6-next-20170825+ #9 [ 34.521619] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.530946] Call Trace: [ 34.533510] dump_stack+0x194/0x257 [ 34.537112] ? arch_local_irq_restore+0x53/0x53 [ 34.541767] panic+0x1e4/0x41c [ 34.544931] ? refcount_error_report+0x214/0x214 [ 34.549657] ? show_regs_print_info+0x65/0x65 [ 34.554136] ? refcount_sub_and_test+0x167/0x1b0 [ 34.558860] __warn+0x1c4/0x1e0 [ 34.562110] ? refcount_sub_and_test+0x167/0x1b0 [ 34.566836] report_bug+0x211/0x2d0 [ 34.570442] fixup_bug+0x40/0x90 [ 34.573778] do_trap+0x260/0x390 [ 34.577122] do_error_trap+0x120/0x390 [ 34.580984] ? do_trap+0x390/0x390 [ 34.584502] ? refcount_sub_and_test+0x167/0x1b0 [ 34.589225] ? vprintk_emit+0x3ea/0x590 [ 34.593179] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 34.597997] do_invalid_op+0x1b/0x20 [ 34.601680] invalid_op+0x18/0x20 [ 34.605103] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 34.610433] RSP: 0018:ffff8801cc066920 EFLAGS: 00010286 [ 34.615769] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 34.623010] RDX: 0000000000000026 RSI: 1ffff1003980cce4 RDI: ffffed003980cd18 [ 34.630249] RBP: ffff8801cc0669b0 R08: ffff8801cc066010 R09: 0000000000000000 [ 34.637489] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1003980cd25 [ 34.644730] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801d2aa8ae4 [ 34.651994] ? refcount_inc+0x50/0x50 [ 34.655765] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 34.660499] ? sctp_association_free+0x2d0/0x930 [ 34.665225] ? sctp_do_sm+0x28e7/0x6dd0 [ 34.669170] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 34.673893] ? sctp_close+0x3c6/0x980 [ 34.677661] ? inet_release+0xed/0x1c0 [ 34.681523] sctp_wfree+0x183/0x620 [ 34.685120] ? __sctp_write_space+0x910/0x910 [ 34.689591] skb_release_head_state+0x124/0x200 [ 34.694232] skb_release_all+0x15/0x60 [ 34.698089] consume_skb+0x153/0x490 [ 34.701770] ? sctp_chunk_put+0x99/0x420 [ 34.705800] ? alloc_skb_with_frags+0x710/0x710 [ 34.710442] ? sctp_chunk_hold+0x20/0x20 [ 34.714478] ? refcount_sub_and_test+0x115/0x1b0 [ 34.719203] ? refcount_inc+0x50/0x50 [ 34.722975] ? mark_held_locks+0xb2/0x100 [ 34.727094] ? sctp_datamsg_put+0x456/0x560 [ 34.731392] sctp_chunk_put+0x29c/0x420 [ 34.735342] ? sctp_chunk_hold+0x20/0x20 [ 34.739385] ? sctp_transport_dst_confirm+0x50/0x50 [ 34.744399] sctp_chunk_free+0x53/0x60 [ 34.748260] __sctp_outq_teardown+0xc7d/0x15a0 [ 34.752813] ? inet6_release+0x50/0x70 [ 34.756675] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 34.761574] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 34.766563] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 34.771548] ? unwind_dump+0x4c0/0x4c0 [ 34.775410] ? unwind_dump+0x4c0/0x4c0 [ 34.779272] ? copy_trace+0x1d0/0x1d0 [ 34.783047] ? check_noncircular+0x20/0x20 [ 34.787253] ? check_noncircular+0x20/0x20 [ 34.791459] ? unwind_get_return_address+0x61/0xa0 [ 34.796358] ? __save_stack_trace+0x61/0xd0 [ 34.800653] ? check_noncircular+0x20/0x20 [ 34.804860] ? print_usage_bug+0x480/0x480 [ 34.809070] ? find_held_lock+0x39/0x1d0 [ 34.813112] ? lock_downgrade+0x990/0x990 [ 34.817238] ? sk_dst_check+0x560/0x560 [ 34.821184] ? rcu_read_lock_sched_held+0x108/0x120 [ 34.826175] ? lock_release+0xd70/0xd70 [ 34.830127] sctp_outq_free+0x15/0x20 [ 34.833900] sctp_association_free+0x2d0/0x930 [ 34.838457] ? sctp_asconf_queue_teardown+0x700/0x700 [ 34.843620] ? sock_def_wakeup+0x222/0x350 [ 34.847827] ? sk_dst_check+0x560/0x560 [ 34.851773] ? sctp_association_put+0x74/0x2f0 [ 34.856326] ? sctp_association_hold+0x20/0x20 [ 34.860882] ? unwind_dump+0x4c0/0x4c0 [ 34.864744] ? sctp_sm_lookup_event+0x95/0x3c0 [ 34.869301] sctp_do_sm+0x28e7/0x6dd0 [ 34.873087] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 34.879119] ? print_usage_bug+0x480/0x480 [ 34.883328] ? __lock_acquire+0x20f4/0x4620 [ 34.887622] ? print_usage_bug+0x480/0x480 [ 34.891832] ? find_held_lock+0x39/0x1d0 [ 34.895874] ? lock_downgrade+0x990/0x990 [ 34.900003] ? skb_dequeue+0x22/0x180 [ 34.903782] ? do_raw_spin_trylock+0x190/0x190 [ 34.908341] ? mark_held_locks+0xb2/0x100 [ 34.912475] ? trace_hardirqs_on+0xd/0x10 [ 34.916607] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 34.921165] sctp_close+0x3c6/0x980 [ 34.924772] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 34.930018] ? unwind_get_return_address+0x61/0xa0 [ 34.934920] ? check_noncircular+0x20/0x20 [ 34.939125] ? depot_save_stack+0x12c/0x490 [ 34.943424] ? ipv6_sock_ac_close+0x2e8/0x3e0 [ 34.948908] ? ipv6_sock_mc_close+0x148/0x1a0 [ 34.953373] ? ipv6_sock_ac_drop+0x580/0x580 [ 34.957755] ? ip_mc_drop_socket+0x1ce/0x230 [ 34.962149] ? __fsnotify_parent+0xb4/0x3a0 [ 34.966445] inet_release+0xed/0x1c0 [ 34.970136] inet6_release+0x50/0x70 [ 34.973822] sock_release+0x8d/0x1e0 [ 34.977508] ? sock_release+0x1e0/0x1e0 [ 34.981451] sock_close+0x16/0x20 [ 34.984875] __fput+0x333/0x7f0 [ 34.988130] ? fput+0x140/0x140 [ 34.991383] ? _raw_spin_unlock_irq+0x27/0x70 [ 34.995862] ____fput+0x15/0x20 [ 34.999112] task_work_run+0x199/0x270 [ 35.002974] ? task_work_cancel+0x210/0x210 [ 35.007266] ? _raw_spin_unlock+0x22/0x30 [ 35.011390] ? switch_task_namespaces+0x87/0xc0 [ 35.016035] do_exit+0xa52/0x1b40 [ 35.019466] ? lock_downgrade+0x990/0x990 [ 35.023597] ? mm_update_next_owner+0x930/0x930 [ 35.028241] ? __lock_is_held+0xbc/0x140 [ 35.032286] ? __fd_install+0x2f7/0x6a0 [ 35.036232] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 35.040962] ? get_unused_fd_flags+0x190/0x190 [ 35.045531] ? copy_user_generic_unrolled+0x89/0xc0 [ 35.050522] ? _copy_to_user+0xa2/0xc0 [ 35.054471] ? fd_install+0x4d/0x60 [ 35.058084] ? SYSC_accept4+0x4f2/0x850 [ 35.062031] ? kernel_accept+0x2f0/0x2f0 [ 35.066072] ? handle_mm_fault+0x4a2/0x860 [ 35.070278] ? __handle_mm_fault+0x39c0/0x39c0 [ 35.074832] ? vmacache_find+0x61/0x270 [ 35.078783] do_group_exit+0x149/0x400 [ 35.082642] ? SyS_exit+0x30/0x30 [ 35.086067] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 35.091052] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 35.095779] SyS_exit_group+0x1d/0x20 [ 35.099548] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 35.104272] RIP: 0033:0x43ea08 [ 35.107432] RSP: 002b:00007ffd4dd1fbf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 35.115113] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ea08 [ 35.122355] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 35.129594] RBP: 0000000000000086 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 35.136833] R10: 000000000000001c R11: 0000000000000246 R12: 0000000000401730 [ 35.144072] R13: 00000000004017c0 R14: 0000000000000000 R15: 0000000000000000 [ 35.151799] Dumping ftrace buffer: [ 35.155364] (ftrace buffer empty) [ 35.159045] Kernel Offset: disabled [ 35.162649] Rebooting in 86400 seconds..