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-6,10.128.15.211' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 47.334555] refcount_t: underflow; use-after-free. [ 47.339655] ------------[ cut here ]------------ [ 47.344577] WARNING: CPU: 0 PID: 3030 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 47.353265] Kernel panic - not syncing: panic_on_warn set ... [ 47.353265] [ 47.360605] CPU: 0 PID: 3030 Comm: syzkaller772454 Not tainted 4.13.0-rc4-next-20170811 #2 [ 47.368976] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.378297] Call Trace: [ 47.380876] dump_stack+0x194/0x257 [ 47.384476] ? arch_local_irq_restore+0x53/0x53 [ 47.389121] panic+0x1e4/0x417 [ 47.392285] ? __warn+0x1d9/0x1d9 [ 47.395705] ? show_regs_print_info+0x65/0x65 [ 47.400179] ? refcount_sub_and_test+0x167/0x1b0 [ 47.404903] __warn+0x1c4/0x1d9 [ 47.408149] ? refcount_sub_and_test+0x167/0x1b0 [ 47.412875] report_bug+0x211/0x2d0 [ 47.416476] fixup_bug+0x40/0x90 [ 47.419808] do_trap+0x260/0x390 [ 47.423146] do_error_trap+0x120/0x390 [ 47.427002] ? do_trap+0x390/0x390 [ 47.430527] ? refcount_sub_and_test+0x167/0x1b0 [ 47.435246] ? vprintk_emit+0x3ea/0x590 [ 47.439196] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 47.444010] do_invalid_op+0x1b/0x20 [ 47.447695] invalid_op+0x1e/0x30 [ 47.451114] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 47.456439] RSP: 0018:ffff8801cfef6300 EFLAGS: 00010282 [ 47.461771] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 47.469007] RDX: 0000000000000026 RSI: 1ffff10039fdec20 RDI: ffffed0039fdec54 [ 47.476250] RBP: ffff8801cfef6390 R08: 0000000000000001 R09: 0000000000000000 [ 47.483507] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff10039fdec61 [ 47.490749] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801c03b2a3c [ 47.498016] ? refcount_inc+0x50/0x50 [ 47.501788] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 47.506509] ? sctp_association_free+0x2d0/0x930 [ 47.511229] ? sctp_do_sm+0x28e7/0x6d90 [ 47.515167] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 47.519887] ? sctp_close+0x3c6/0x980 [ 47.523657] ? inet_release+0xed/0x1c0 [ 47.527557] sctp_wfree+0x183/0x620 [ 47.531156] ? __sctp_write_space+0x910/0x910 [ 47.535625] skb_release_head_state+0x124/0x200 [ 47.540265] skb_release_all+0x15/0x60 [ 47.544121] consume_skb+0x153/0x490 [ 47.547806] ? sctp_chunk_put+0x99/0x420 [ 47.551853] ? alloc_skb_with_frags+0x710/0x710 [ 47.556578] ? sctp_chunk_hold+0x20/0x20 [ 47.560786] ? refcount_sub_and_test+0x115/0x1b0 [ 47.565519] ? refcount_inc+0x50/0x50 [ 47.569287] ? mark_held_locks+0xaf/0x100 [ 47.573409] ? sctp_datamsg_put+0x456/0x560 [ 47.577705] sctp_chunk_put+0x29c/0x420 [ 47.581651] ? sctp_chunk_hold+0x20/0x20 [ 47.585685] ? sctp_transport_dst_confirm+0x50/0x50 [ 47.590672] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 47.595831] ? lock_release+0xa40/0xa40 [ 47.599773] ? __read_once_size_nocheck.constprop.8+0x10/0x10 [ 47.605635] ? entry_SYSCALL_64_fastpath+0xbc/0xbe [ 47.610540] ? bpf_prog_kallsyms_find+0xbd/0x440 [ 47.615264] ? show_initstate+0xb0/0xb0 [ 47.619217] sctp_chunk_free+0x53/0x60 [ 47.623079] __sctp_outq_teardown+0xc7d/0x15a0 [ 47.627627] ? lock_downgrade+0x990/0x990 [ 47.631759] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 47.636655] ? unwind_dump+0x4c0/0x4c0 [ 47.640522] ? is_bpf_text_address+0xa4/0x120 [ 47.644984] ? __kernel_text_address+0xae/0xe0 [ 47.649552] ? unwind_get_return_address+0x61/0xa0 [ 47.654463] ? __save_stack_trace+0x7e/0xd0 [ 47.658758] ? add_lock_to_list.isra.35+0x1ff/0x4f0 [ 47.663929] ? SOFTIRQ_verbose+0x10/0x10 [ 47.667957] ? save_stack_trace+0x16/0x20 [ 47.672083] ? check_noncircular+0x20/0x20 [ 47.676295] ? print_usage_bug+0x480/0x480 [ 47.680524] ? lock_acquire+0x1d5/0x580 [ 47.684465] ? lock_acquire+0x1d5/0x580 [ 47.688414] ? lock_timer_base+0x1a3/0x2b0 [ 47.692627] ? find_held_lock+0x35/0x1d0 [ 47.696667] ? sock_def_wakeup+0x1f9/0x350 [ 47.700869] ? lock_downgrade+0x990/0x990 [ 47.704985] ? lock_release+0xa40/0xa40 [ 47.708930] sctp_outq_free+0x15/0x20 [ 47.712695] sctp_association_free+0x2d0/0x930 [ 47.717248] ? sctp_asconf_queue_teardown+0x700/0x700 [ 47.722426] ? sock_def_wakeup+0x222/0x350 [ 47.726633] ? sk_dst_check+0x560/0x560 [ 47.730574] ? sctp_association_put+0x74/0x2f0 [ 47.735120] ? sctp_association_hold+0x20/0x20 [ 47.739672] ? fault_create_debugfs_attr+0x1f0/0x1f0 [ 47.744740] ? __kernel_text_address+0xae/0xe0 [ 47.749290] ? unwind_get_return_address+0x61/0xa0 [ 47.754195] ? sctp_sm_lookup_event+0x95/0x3c0 [ 47.758745] sctp_do_sm+0x28e7/0x6d90 [ 47.762534] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 47.768585] ? save_stack_trace+0x16/0x20 [ 47.772701] ? kasan_slab_free+0x71/0xc0 [ 47.776731] ? print_usage_bug+0x480/0x480 [ 47.780932] ? __lock_acquire+0x6aa/0x3bc0 [ 47.785132] ? print_usage_bug+0x480/0x480 [ 47.789336] ? __lock_acquire+0x6aa/0x3bc0 [ 47.793544] ? find_held_lock+0x35/0x1d0 [ 47.797672] ? skb_dequeue+0x12a/0x180 [ 47.801535] ? lock_downgrade+0x990/0x990 [ 47.805655] ? do_raw_spin_trylock+0x190/0x190 [ 47.810209] ? mark_held_locks+0xaf/0x100 [ 47.814331] ? trace_hardirqs_on+0xd/0x10 [ 47.818454] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 47.823018] sctp_close+0x3c6/0x980 [ 47.826634] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 47.831879] ? unwind_get_return_address+0x61/0xa0 [ 47.836779] ? check_noncircular+0x20/0x20 [ 47.840991] ? check_noncircular+0x20/0x20 [ 47.845206] ? ipv6_sock_ac_close+0x2e8/0x3e0 [ 47.849686] ? ipv6_sock_mc_close+0x148/0x1a0 [ 47.854147] ? ipv6_sock_ac_drop+0x580/0x580 [ 47.858523] ? ip_mc_drop_socket+0x1ce/0x230 [ 47.862899] ? __fsnotify_parent+0xb4/0x3a0 [ 47.867187] inet_release+0xed/0x1c0 [ 47.870869] inet6_release+0x50/0x70 [ 47.874550] sock_release+0x8d/0x1e0 [ 47.878233] ? sock_release+0x1e0/0x1e0 [ 47.882173] sock_close+0x16/0x20 [ 47.885596] __fput+0x327/0x7e0 [ 47.888848] ? fput+0x140/0x140 [ 47.892094] ? _raw_spin_unlock_irq+0x27/0x70 [ 47.896562] ____fput+0x15/0x20 [ 47.899808] task_work_run+0x199/0x270 [ 47.903666] ? task_work_cancel+0x210/0x210 [ 47.907958] ? _raw_spin_unlock+0x22/0x30 [ 47.912076] ? switch_task_namespaces+0x87/0xc0 [ 47.916716] do_exit+0xa52/0x1b30 [ 47.920148] ? print_usage_bug+0x480/0x480 [ 47.924358] ? mm_update_next_owner+0x930/0x930 [ 47.929007] ? check_noncircular+0x20/0x20 [ 47.933207] ? check_noncircular+0x20/0x20 [ 47.937413] ? find_held_lock+0x35/0x1d0 [ 47.941460] ? find_held_lock+0x35/0x1d0 [ 47.945494] ? check_noncircular+0x20/0x20 [ 47.949696] ? check_noncircular+0x20/0x20 [ 47.953914] ? lock_downgrade+0x990/0x990 [ 47.958037] ? do_raw_spin_trylock+0x190/0x190 [ 47.962594] ? reacquire_held_locks+0x1fd/0x3d0 [ 47.967227] ? mark_held_locks+0xaf/0x100 [ 47.971340] ? reacquire_held_locks+0x1fd/0x3d0 [ 47.975975] ? check_noncircular+0x20/0x20 [ 47.980178] ? find_held_lock+0x35/0x1d0 [ 47.984213] ? release_sock+0x1d4/0x2a0 [ 47.988152] ? lock_downgrade+0x990/0x990 [ 47.992266] ? lock_downgrade+0x990/0x990 [ 47.996383] ? find_held_lock+0x35/0x1d0 [ 48.000424] ? get_signal+0x855/0x17e0 [ 48.004278] ? lock_downgrade+0x990/0x990 [ 48.008399] do_group_exit+0x149/0x400 [ 48.012252] ? __lock_is_held+0xb6/0x140 [ 48.016277] ? SyS_exit+0x30/0x30 [ 48.019697] ? _raw_spin_unlock_irq+0x27/0x70 [ 48.024159] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 48.029151] get_signal+0x7e8/0x17e0 [ 48.032855] ? ptrace_notify+0x130/0x130 [ 48.036883] ? __local_bh_enable_ip+0x9d/0x160 [ 48.041433] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 48.046422] ? release_sock+0x1d4/0x2a0 [ 48.050360] ? trace_hardirqs_on+0xd/0x10 [ 48.054473] ? __local_bh_enable_ip+0x9d/0x160 [ 48.059031] ? _raw_spin_unlock_bh+0x30/0x40 [ 48.063405] ? release_sock+0x1d4/0x2a0 [ 48.067351] ? trace_hardirqs_on+0xd/0x10 [ 48.071469] do_signal+0x94/0x1ee0 [ 48.074979] ? inet_sendmsg+0x11f/0x5e0 [ 48.078923] ? inet_sendmsg+0x126/0x5e0 [ 48.082866] ? __might_sleep+0x95/0x190 [ 48.086812] ? setup_sigcontext+0x7d0/0x7d0 [ 48.091102] ? selinux_socket_sendmsg+0x36/0x40 [ 48.095738] ? security_socket_sendmsg+0x89/0xb0 [ 48.100462] ? inet_recvmsg+0x5f0/0x5f0 [ 48.104404] ? sock_sendmsg+0x4f/0x110 [ 48.108267] ? fput+0xd2/0x140 [ 48.111426] ? SYSC_sendto+0x40d/0x5a0 [ 48.115285] ? SYSC_connect+0x470/0x470 [ 48.119228] ? find_held_lock+0x35/0x1d0 [ 48.123438] ? exit_to_usermode_loop+0x98/0x300 [ 48.128089] exit_to_usermode_loop+0x224/0x300 [ 48.132642] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 48.138166] ? handle_mm_fault+0x4e3/0x940 [ 48.142366] ? down_read_trylock+0xdb/0x170 [ 48.146658] syscall_return_slowpath+0x42f/0x500 [ 48.151381] ? prepare_exit_to_usermode+0x2c0/0x2c0 [ 48.156364] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 48.161261] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 48.166251] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 48.170989] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 48.175713] RIP: 0033:0x445429 [ 48.178869] RSP: 002b:00007ffb0dde1db8 EFLAGS: 00000212 ORIG_RAX: 000000000000002c [ 48.186541] RAX: 00000000000000d1 RBX: 0000000000000000 RCX: 0000000000445429 [ 48.193775] RDX: 00000000000000d1 RSI: 0000000020446000 RDI: 0000000000000003 [ 48.201010] RBP: 0000000000000000 R08: 0000000020e88000 R09: 0000000000000080 [ 48.208244] R10: 0000000000000010 R11: 0000000000000212 R12: 0000000000000000 [ 48.215481] R13: 00007fff2f2c678f R14: 00007ffb0dde29c0 R15: 0000000000000000 [ 48.222923] Dumping ftrace buffer: [ 48.226486] (ftrace buffer empty) [ 48.230164] Kernel Offset: disabled [ 48.233762] Rebooting in 86400 seconds..