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-3,10.128.0.7' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 31.727302] refcount_t: underflow; use-after-free. [ 31.728230] ------------[ cut here ]------------ [ 31.728895] WARNING: CPU: 1 PID: 2924 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 31.730191] Kernel panic - not syncing: panic_on_warn set ... [ 31.730191] [ 31.731192] CPU: 1 PID: 2924 Comm: syzkaller290734 Not tainted 4.13.0-rc4+ #31 [ 31.732191] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.733421] Call Trace: [ 31.733816] dump_stack+0x194/0x257 [ 31.734308] ? arch_local_irq_restore+0x53/0x53 [ 31.734943] panic+0x1e4/0x417 [ 31.735377] ? __warn+0x1d9/0x1d9 [ 31.735843] ? show_regs_print_info+0x65/0x65 [ 31.736482] ? refcount_sub_and_test+0x167/0x1b0 [ 31.737168] __warn+0x1c4/0x1d9 [ 31.737620] ? refcount_sub_and_test+0x167/0x1b0 [ 31.738302] report_bug+0x211/0x2d0 [ 31.738798] fixup_bug+0x40/0x90 [ 31.739256] do_trap+0x260/0x390 [ 31.739719] do_error_trap+0x120/0x390 [ 31.740242] ? vprintk_emit+0x49b/0x590 [ 31.740778] ? do_trap+0x390/0x390 [ 31.741258] ? refcount_sub_and_test+0x167/0x1b0 [ 31.741917] ? vprintk_emit+0x3ea/0x590 [ 31.742460] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 31.743128] do_invalid_op+0x1b/0x20 [ 31.743648] invalid_op+0x1e/0x30 [ 31.744114] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 31.744835] RSP: 0018:ffff8801d35c6ce8 EFLAGS: 00010286 [ 31.745575] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 31.746529] RDX: 0000000000000026 RSI: 1ffff1003a6b8d5d RDI: ffffed003a6b8d91 [ 31.747833] RBP: ffff8801d35c6d78 R08: 0000000000000001 R09: 0000000000000000 [ 31.755072] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1003a6b8d9e [ 31.762311] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801d006927c [ 31.769570] ? refcount_sub_and_test+0x167/0x1b0 [ 31.774294] ? refcount_inc+0x50/0x50 [ 31.778069] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 31.782817] ? sctp_association_free+0x2d0/0x930 [ 31.787541] ? sctp_do_sm+0x28e7/0x6d90 [ 31.791482] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 31.796204] ? sctp_close+0x3c6/0x980 [ 31.799971] ? inet_release+0xed/0x1c0 [ 31.803830] sctp_wfree+0x183/0x620 [ 31.807425] ? __sctp_write_space+0x910/0x910 [ 31.811889] skb_release_head_state+0x124/0x200 [ 31.816530] skb_release_all+0x15/0x60 [ 31.820386] consume_skb+0x153/0x490 [ 31.824066] ? sctp_chunk_put+0x99/0x420 [ 31.828094] ? pskb_carve+0x1db0/0x1db0 [ 31.832037] ? sctp_chunk_hold+0x20/0x20 [ 31.836071] ? refcount_sub_and_test+0x115/0x1b0 [ 31.840794] ? refcount_inc+0x50/0x50 [ 31.844561] ? mark_held_locks+0xaf/0x100 [ 31.848678] ? sctp_datamsg_put+0x456/0x560 [ 31.852978] sctp_chunk_put+0x29c/0x420 [ 31.856923] ? sctp_chunk_hold+0x20/0x20 [ 31.860956] ? sctp_transport_dst_confirm+0x50/0x50 [ 31.865951] ? check_noncircular+0x20/0x20 [ 31.870152] ? check_noncircular+0x20/0x20 [ 31.874354] ? check_noncircular+0x20/0x20 [ 31.878570] sctp_chunk_free+0x53/0x60 [ 31.882430] __sctp_outq_teardown+0xc7d/0x15a0 [ 31.886991] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 31.891894] ? try_to_wake_up+0xf9/0x1600 [ 31.896019] ? lock_downgrade+0x990/0x990 [ 31.900136] ? lock_downgrade+0x990/0x990 [ 31.904258] ? do_raw_spin_trylock+0x190/0x190 [ 31.908805] ? do_raw_spin_trylock+0x190/0x190 [ 31.913368] ? trace_hardirqs_off+0xd/0x10 [ 31.917572] ? _raw_spin_unlock_irqrestore+0xa6/0xba [ 31.922643] ? try_to_wake_up+0xf9/0x1600 [ 31.926764] ? check_noncircular+0x20/0x20 [ 31.930971] ? migrate_swap_stop+0x970/0x970 [ 31.935350] ? save_stack_trace+0x16/0x20 [ 31.939467] ? save_trace+0x11f/0x350 [ 31.943240] ? print_usage_bug+0x480/0x480 [ 31.947442] ? lock_acquire+0x1d5/0x580 [ 31.951389] ? lock_acquire+0x1d5/0x580 [ 31.955332] ? lock_timer_base+0x1a3/0x2b0 [ 31.959548] ? find_held_lock+0x35/0x1d0 [ 31.963586] ? sock_def_wakeup+0x1f9/0x350 [ 31.967788] ? lock_downgrade+0x990/0x990 [ 31.971900] ? find_held_lock+0x35/0x1d0 [ 31.975929] ? lock_release+0xa40/0xa40 [ 31.979886] sctp_outq_free+0x15/0x20 [ 31.983658] sctp_association_free+0x2d0/0x930 [ 31.988229] ? sctp_asconf_queue_teardown+0x700/0x700 [ 31.993388] ? sock_def_wakeup+0x222/0x350 [ 31.997589] ? sk_dst_check+0x560/0x560 [ 32.001535] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 32.006520] ? trace_hardirqs_on+0xd/0x10 [ 32.010638] ? __wake_up+0x3f/0x50 [ 32.014150] sctp_do_sm+0x28e7/0x6d90 [ 32.017918] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 32.023085] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 32.029119] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 32.034277] ? print_usage_bug+0x480/0x480 [ 32.038490] ? print_usage_bug+0x480/0x480 [ 32.042705] ? reacquire_held_locks+0x1fd/0x3d0 [ 32.047347] ? find_held_lock+0x35/0x1d0 [ 32.051390] ? skb_dequeue+0x12a/0x180 [ 32.055248] ? lock_downgrade+0x990/0x990 [ 32.059372] ? do_raw_spin_trylock+0x190/0x190 [ 32.063928] ? mark_held_locks+0xaf/0x100 [ 32.068053] ? trace_hardirqs_on+0xd/0x10 [ 32.072179] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 32.076734] sctp_close+0x3c6/0x980 [ 32.080338] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 32.085586] ? check_noncircular+0x20/0x20 [ 32.089788] ? lock_downgrade+0x990/0x990 [ 32.093902] ? lock_downgrade+0x990/0x990 [ 32.098019] ? do_raw_spin_trylock+0x190/0x190 [ 32.102571] ? locks_remove_file+0x414/0x560 [ 32.106948] ? fcntl_setlk+0x10c0/0x10c0 [ 32.110980] ? __fsnotify_parent+0xb4/0x3a0 [ 32.115275] ? ip_mc_drop_socket+0x1ce/0x230 [ 32.119656] inet_release+0xed/0x1c0 [ 32.123356] sock_release+0x8d/0x1e0 [ 32.127037] ? sock_release+0x1e0/0x1e0 [ 32.130977] sock_close+0x16/0x20 [ 32.134399] __fput+0x327/0x7e0 [ 32.137658] ? fput+0x140/0x140 [ 32.141080] ? alloc_fdtable+0x280/0x280 [ 32.145109] ? cpumask_weight.constprop.3+0x45/0x45 [ 32.150097] ____fput+0x15/0x20 [ 32.153343] task_work_run+0x18a/0x260 [ 32.157199] ? task_work_cancel+0x210/0x210 [ 32.161490] ? exit_to_usermode_loop+0x98/0x2d0 [ 32.166131] exit_to_usermode_loop+0x26d/0x2d0 [ 32.170684] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 32.176192] ? __do_page_fault+0x2b8/0xb60 [ 32.180398] syscall_return_slowpath+0x3a7/0x450 [ 32.185121] ? prepare_exit_to_usermode+0x220/0x220 [ 32.190104] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 32.195002] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 32.199985] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 32.204713] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 32.209434] RIP: 0033:0x445d99 [ 32.212592] RSP: 002b:00007feb5f0dfdc8 EFLAGS: 00000202 ORIG_RAX: 000000000000002b [ 32.220264] RAX: ffffffffffffff99 RBX: 0000000000000000 RCX: 0000000000445d99 [ 32.227499] RDX: 0000000020ffd000 RSI: 0000000020ffc000 RDI: 0000000000000003 [ 32.234736] RBP: 0000000000000000 R08: 00007feb5f0e0700 R09: 00007feb5f0e0700 [ 32.241972] R10: 00007feb5f0e0700 R11: 0000000000000202 R12: 0000000000000000 [ 32.249207] R13: 00007fff8d1a479f R14: 00007feb5f0e09c0 R15: 0000000000000000 [ 32.257053] Dumping ftrace buffer: [ 32.260605] (ftrace buffer empty) [ 32.264282] Kernel Offset: disabled [ 32.267879] Rebooting in 86400 seconds..