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-0,10.128.15.198' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 30.381743] refcount_t: underflow; use-after-free. [ 30.382635] ------------[ cut here ]------------ [ 30.383502] WARNING: CPU: 1 PID: 3010 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 30.384746] Kernel panic - not syncing: panic_on_warn set ... [ 30.384746] [ 30.385716] CPU: 1 PID: 3010 Comm: syzkaller469126 Not tainted 4.13.0-rc6+ #46 [ 30.386679] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.387971] Call Trace: [ 30.388330] dump_stack+0x194/0x257 [ 30.388847] ? arch_local_irq_restore+0x53/0x53 [ 30.389479] panic+0x1e4/0x417 [ 30.389933] ? __warn+0x1d9/0x1d9 [ 30.390398] ? show_regs_print_info+0x65/0x65 [ 30.391027] ? refcount_sub_and_test+0x167/0x1b0 [ 30.391699] __warn+0x1c4/0x1d9 [ 30.392143] ? refcount_sub_and_test+0x167/0x1b0 [ 30.392795] report_bug+0x211/0x2d0 [ 30.393346] fixup_bug+0x40/0x90 [ 30.393816] do_trap+0x260/0x390 [ 30.394277] do_error_trap+0x120/0x390 [ 30.394817] ? do_trap+0x390/0x390 [ 30.395294] ? refcount_sub_and_test+0x167/0x1b0 [ 30.395926] ? vprintk_emit+0x3ea/0x590 [ 30.396467] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 30.397116] do_invalid_op+0x1b/0x20 [ 30.397634] invalid_op+0x1e/0x30 [ 30.398099] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 30.398871] RSP: 0018:ffff8801d0ca6310 EFLAGS: 00010282 [ 30.399585] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 30.400589] RDX: 0000000000000026 RSI: 1ffff1003a194c22 RDI: ffffed003a194c56 [ 30.401543] RBP: ffff8801d0ca63a0 R08: 0000000000000001 R09: 0000000000000000 [ 30.406691] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1003a194c63 [ 30.413938] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801d3bd7a3c [ 30.421209] ? refcount_inc+0x50/0x50 [ 30.424981] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 30.429797] ? sctp_association_free+0x2d0/0x930 [ 30.434530] ? sctp_do_sm+0x28e7/0x6d90 [ 30.438478] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 30.443202] ? sctp_close+0x3c6/0x980 [ 30.446973] ? inet_release+0xed/0x1c0 [ 30.450835] sctp_wfree+0x183/0x620 [ 30.454433] ? __sctp_write_space+0x910/0x910 [ 30.458902] skb_release_head_state+0x124/0x200 [ 30.463544] skb_release_all+0x15/0x60 [ 30.467402] consume_skb+0x153/0x490 [ 30.471086] ? sctp_chunk_put+0x99/0x420 [ 30.475115] ? pskb_carve+0x1db0/0x1db0 [ 30.479058] ? sctp_chunk_hold+0x20/0x20 [ 30.483093] ? refcount_sub_and_test+0x115/0x1b0 [ 30.487833] ? refcount_inc+0x50/0x50 [ 30.491603] ? mark_held_locks+0xaf/0x100 [ 30.495735] ? sctp_datamsg_put+0x456/0x560 [ 30.500035] sctp_chunk_put+0x29c/0x420 [ 30.503980] ? sctp_chunk_hold+0x20/0x20 [ 30.508014] ? sctp_transport_dst_confirm+0x50/0x50 [ 30.513006] ? noop_count+0x40/0x40 [ 30.516614] sctp_chunk_free+0x53/0x60 [ 30.520472] __sctp_outq_teardown+0xc7d/0x15a0 [ 30.525032] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 30.529932] ? lock_downgrade+0x990/0x990 [ 30.534054] ? lock_release+0xa40/0xa40 [ 30.538008] ? __free_insn_slot+0x5c0/0x5c0 [ 30.542303] ? update_stack_state+0x700/0x700 [ 30.546768] ? print_usage_bug+0x480/0x480 [ 30.550982] ? is_bpf_text_address+0xa4/0x120 [ 30.555449] ? __kernel_text_address+0xae/0xe0 [ 30.560006] ? unwind_get_return_address+0x61/0xa0 [ 30.564910] ? __save_stack_trace+0x7e/0xd0 [ 30.569205] ? check_noncircular+0x20/0x20 [ 30.573409] ? print_usage_bug+0x480/0x480 [ 30.577621] ? SOFTIRQ_verbose+0x10/0x10 [ 30.581652] ? save_stack_trace+0x16/0x20 [ 30.585769] ? save_trace+0x11f/0x350 [ 30.589545] ? lock_acquire+0x1d5/0x580 [ 30.593490] ? lock_acquire+0x1d5/0x580 [ 30.597436] ? lock_timer_base+0x1a3/0x2b0 [ 30.601643] ? find_held_lock+0x35/0x1d0 [ 30.605687] ? sock_def_wakeup+0x1f9/0x350 [ 30.609895] ? lock_downgrade+0x990/0x990 [ 30.614014] ? lock_release+0xa40/0xa40 [ 30.617964] sctp_outq_free+0x15/0x20 [ 30.621734] sctp_association_free+0x2d0/0x930 [ 30.626289] ? sctp_asconf_queue_teardown+0x700/0x700 [ 30.631450] ? sock_def_wakeup+0x222/0x350 [ 30.635654] ? sk_dst_check+0x560/0x560 [ 30.639599] ? sctp_association_put+0x74/0x2f0 [ 30.644150] ? sctp_association_hold+0x20/0x20 [ 30.648703] ? print_usage_bug+0x480/0x480 [ 30.652909] ? sctp_sm_lookup_event+0x95/0x3c0 [ 30.657462] sctp_do_sm+0x28e7/0x6d90 [ 30.661240] ? check_noncircular+0x20/0x20 [ 30.665454] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 30.671484] ? print_usage_bug+0x480/0x480 [ 30.675686] ? exit_to_usermode_loop+0x224/0x300 [ 30.680407] ? syscall_return_slowpath+0x3a7/0x450 [ 30.685308] ? print_usage_bug+0x480/0x480 [ 30.689513] ? find_held_lock+0x35/0x1d0 [ 30.693554] ? find_held_lock+0x35/0x1d0 [ 30.697596] ? skb_dequeue+0x12a/0x180 [ 30.701452] ? lock_downgrade+0x990/0x990 [ 30.705586] ? do_raw_spin_trylock+0x190/0x190 [ 30.710138] ? mark_held_locks+0xaf/0x100 [ 30.714268] ? trace_hardirqs_on+0xd/0x10 [ 30.718397] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 30.722951] sctp_close+0x3c6/0x980 [ 30.726554] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 30.731800] ? unwind_get_return_address+0x61/0xa0 [ 30.736704] ? trace_hardirqs_off+0xd/0x10 [ 30.740906] ? _raw_spin_unlock_irqrestore+0xa6/0xba [ 30.745976] ? check_noncircular+0x20/0x20 [ 30.750185] ? ipv6_sock_ac_close+0x2e8/0x3e0 [ 30.754650] ? ipv6_sock_mc_close+0x148/0x1a0 [ 30.759114] ? ipv6_sock_ac_drop+0x580/0x580 [ 30.763486] ? ip_mc_drop_socket+0x1ce/0x230 [ 30.767863] ? __fsnotify_parent+0xb4/0x3a0 [ 30.772153] inet_release+0xed/0x1c0 [ 30.775838] inet6_release+0x50/0x70 [ 30.779518] sock_release+0x8d/0x1e0 [ 30.783203] ? sock_release+0x1e0/0x1e0 [ 30.787141] sock_close+0x16/0x20 [ 30.790560] __fput+0x327/0x7e0 [ 30.793813] ? fput+0x140/0x140 [ 30.797065] ? do_raw_spin_trylock+0x190/0x190 [ 30.801614] ? check_same_owner+0x320/0x320 [ 30.805905] ____fput+0x15/0x20 [ 30.809151] task_work_run+0x18a/0x260 [ 30.813006] ? task_work_cancel+0x210/0x210 [ 30.817325] ? _raw_spin_unlock+0x22/0x30 [ 30.821444] ? switch_task_namespaces+0x87/0xc0 [ 30.826085] do_exit+0xa3a/0x1b10 [ 30.829507] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 30.834667] ? print_usage_bug+0x480/0x480 [ 30.838874] ? mm_update_next_owner+0x930/0x930 [ 30.843544] ? check_noncircular+0x20/0x20 [ 30.847745] ? check_noncircular+0x20/0x20 [ 30.851953] ? find_held_lock+0x35/0x1d0 [ 30.855984] ? find_held_lock+0x35/0x1d0 [ 30.860014] ? check_noncircular+0x20/0x20 [ 30.864215] ? check_noncircular+0x20/0x20 [ 30.868426] ? lock_downgrade+0x990/0x990 [ 30.872552] ? do_raw_spin_trylock+0x190/0x190 [ 30.877105] ? reacquire_held_locks+0x1fd/0x3d0 [ 30.881741] ? mark_held_locks+0xaf/0x100 [ 30.885853] ? reacquire_held_locks+0x1fd/0x3d0 [ 30.890490] ? check_noncircular+0x20/0x20 [ 30.894692] ? find_held_lock+0x35/0x1d0 [ 30.898727] ? release_sock+0x1d4/0x2a0 [ 30.902667] ? lock_downgrade+0x990/0x990 [ 30.906781] ? lock_downgrade+0x990/0x990 [ 30.910899] ? find_held_lock+0x35/0x1d0 [ 30.914937] ? get_signal+0x855/0x17e0 [ 30.918791] ? lock_downgrade+0x990/0x990 [ 30.922915] do_group_exit+0x149/0x400 [ 30.926768] ? __lock_is_held+0xb6/0x140 [ 30.930797] ? SyS_exit+0x30/0x30 [ 30.934216] ? _raw_spin_unlock_irq+0x27/0x70 [ 30.938684] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 30.943676] get_signal+0x7e8/0x17e0 [ 30.947380] ? ptrace_notify+0x130/0x130 [ 30.951407] ? inet_autobind+0x1f/0x180 [ 30.955347] ? __local_bh_enable_ip+0x9d/0x160 [ 30.959896] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 30.964886] ? release_sock+0x1d4/0x2a0 [ 30.968828] ? trace_hardirqs_on+0xd/0x10 [ 30.972945] ? __local_bh_enable_ip+0x9d/0x160 [ 30.977499] ? _raw_spin_unlock_bh+0x30/0x40 [ 30.981877] ? release_sock+0x1d4/0x2a0 [ 30.985823] ? trace_hardirqs_on+0xd/0x10 [ 30.989946] do_signal+0x94/0x1ee0 [ 30.993456] ? inet_sendmsg+0x11f/0x5e0 [ 30.997396] ? inet_sendmsg+0x126/0x5e0 [ 31.001337] ? __might_sleep+0x95/0x190 [ 31.005283] ? setup_sigcontext+0x7d0/0x7d0 [ 31.009578] ? selinux_socket_sendmsg+0x36/0x40 [ 31.014217] ? security_socket_sendmsg+0x89/0xb0 [ 31.018945] ? inet_recvmsg+0x5f0/0x5f0 [ 31.022890] ? sock_sendmsg+0x4f/0x110 [ 31.026745] ? fput+0xd2/0x140 [ 31.029904] ? SYSC_sendto+0x40d/0x5a0 [ 31.033762] ? SYSC_connect+0x470/0x470 [ 31.037708] ? find_held_lock+0x35/0x1d0 [ 31.041740] ? exit_to_usermode_loop+0x98/0x300 [ 31.046394] exit_to_usermode_loop+0x224/0x300 [ 31.050949] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 31.056455] ? handle_mm_fault+0x4a2/0x860 [ 31.060659] ? down_read_trylock+0xdb/0x170 [ 31.064957] syscall_return_slowpath+0x3a7/0x450 [ 31.069681] ? prepare_exit_to_usermode+0x220/0x220 [ 31.074668] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 31.079568] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 31.084557] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 31.089291] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 31.094014] RIP: 0033:0x445429 [ 31.097174] RSP: 002b:00007f8da55fadb8 EFLAGS: 00000212 ORIG_RAX: 000000000000002c [ 31.104852] RAX: 00000000000000d1 RBX: 0000000000000000 RCX: 0000000000445429 [ 31.112093] RDX: 00000000000000d1 RSI: 0000000020446000 RDI: 0000000000000003 [ 31.119331] RBP: 0000000000000000 R08: 0000000020e88000 R09: 0000000000000080 [ 31.126571] R10: 0000000000000010 R11: 0000000000000212 R12: 0000000000000000 [ 31.133815] R13: 00007fff70813aff R14: 00007f8da55fb9c0 R15: 0000000000000000 [ 31.141225] Dumping ftrace buffer: [ 31.144793] (ftrace buffer empty) [ 31.148473] Kernel Offset: disabled [ 31.152071] Rebooting in 86400 seconds..