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-3,10.128.0.23' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 42.165468] refcount_t: underflow; use-after-free. [ 42.166329] ------------[ cut here ]------------ [ 42.166973] WARNING: CPU: 1 PID: 2992 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 42.168245] Kernel panic - not syncing: panic_on_warn set ... [ 42.168245] [ 42.169217] CPU: 1 PID: 2992 Comm: syzkaller627312 Not tainted 4.14.0-rc6+ #145 [ 42.170252] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.171471] Call Trace: [ 42.171835] dump_stack+0x194/0x257 [ 42.172331] ? arch_local_irq_restore+0x53/0x53 [ 42.172964] panic+0x1e4/0x417 [ 42.173399] ? __warn+0x1d9/0x1d9 [ 42.173868] ? show_regs_print_info+0x65/0x65 [ 42.174491] ? refcount_sub_and_test+0x167/0x1b0 [ 42.175127] __warn+0x1c4/0x1d9 [ 42.175573] ? refcount_sub_and_test+0x167/0x1b0 [ 42.176225] report_bug+0x211/0x2d0 [ 42.176724] fixup_bug+0x40/0x90 [ 42.177180] do_trap+0x260/0x390 [ 42.177641] do_error_trap+0x120/0x390 [ 42.178160] ? vprintk_emit+0x49b/0x590 [ 42.178697] ? do_trap+0x390/0x390 [ 42.179175] ? refcount_sub_and_test+0x167/0x1b0 [ 42.179808] ? vprintk_emit+0x3ea/0x590 [ 42.180367] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 42.181019] do_invalid_op+0x1b/0x20 [ 42.181521] invalid_op+0x18/0x20 [ 42.181986] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 42.182695] RSP: 0018:ffff8801d222e908 EFLAGS: 00010286 [ 42.183406] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 42.184359] RDX: 0000000000000026 RSI: 1ffff1003a445ce1 RDI: ffffed003a445d15 [ 42.185311] RBP: ffff8801d222e998 R08: 0000000000000001 R09: 0000000000000000 [ 42.190990] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1003a445d22 [ 42.198227] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801d2756a3c [ 42.205486] ? refcount_sub_and_test+0x167/0x1b0 [ 42.210219] ? refcount_inc+0x50/0x50 [ 42.213990] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 42.218712] ? sctp_association_free+0x2d0/0x930 [ 42.223436] ? sctp_do_sm+0x28e7/0x6dd0 [ 42.227374] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 42.232094] ? sctp_close+0x3c6/0x980 [ 42.235864] ? inet_release+0xed/0x1c0 [ 42.239722] sctp_wfree+0x183/0x620 [ 42.243317] ? __sctp_write_space+0x910/0x910 [ 42.247780] skb_release_head_state+0x124/0x200 [ 42.252416] skb_release_all+0x15/0x60 [ 42.256269] consume_skb+0x153/0x490 [ 42.259949] ? sctp_chunk_put+0x99/0x420 [ 42.263977] ? alloc_skb_with_frags+0x710/0x710 [ 42.268615] ? sctp_chunk_hold+0x20/0x20 [ 42.272649] ? refcount_sub_and_test+0x115/0x1b0 [ 42.277371] ? refcount_inc+0x50/0x50 [ 42.281152] ? mark_held_locks+0xaf/0x100 [ 42.285282] ? sctp_datamsg_put+0x456/0x560 [ 42.289590] sctp_chunk_put+0x29c/0x420 [ 42.293539] ? sctp_chunk_hold+0x20/0x20 [ 42.297572] ? sctp_transport_dst_confirm+0x50/0x50 [ 42.302559] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 42.307719] ? lock_release+0xa40/0xa40 [ 42.311664] ? show_initstate+0xb0/0xb0 [ 42.315609] sctp_chunk_free+0x53/0x60 [ 42.319466] __sctp_outq_teardown+0xc7d/0x15a0 [ 42.324023] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 42.328926] ? rcutorture_record_progress+0x10/0x10 [ 42.333916] ? is_bpf_text_address+0xa4/0x120 [ 42.338379] ? kernel_text_address+0x102/0x140 [ 42.342930] ? __kernel_text_address+0xd/0x40 [ 42.347395] ? unwind_get_return_address+0x61/0xa0 [ 42.352294] ? __save_stack_trace+0x7e/0xd0 [ 42.356591] ? add_lock_to_list.isra.33+0x292/0x39b [ 42.361584] ? check_noncircular+0x20/0x20 [ 42.365793] ? print_irqtrace_events+0x270/0x270 [ 42.370545] ? lock_acquire+0x1d5/0x580 [ 42.374486] ? lock_acquire+0x1d5/0x580 [ 42.378429] ? lock_timer_base+0x1a3/0x2b0 [ 42.382634] ? find_held_lock+0x35/0x1d0 [ 42.386670] ? sock_def_wakeup+0x1f9/0x350 [ 42.390873] ? lock_downgrade+0x990/0x990 [ 42.394993] ? lock_release+0xa40/0xa40 [ 42.398942] sctp_outq_free+0x15/0x20 [ 42.402711] sctp_association_free+0x2d0/0x930 [ 42.407264] ? sctp_asconf_queue_teardown+0x700/0x700 [ 42.412421] ? sock_def_wakeup+0x222/0x350 [ 42.416624] ? sk_dst_check+0x560/0x560 [ 42.420568] ? sctp_association_put+0x74/0x2f0 [ 42.425117] ? sctp_association_hold+0x20/0x20 [ 42.429669] ? __lock_is_held+0xb6/0x140 [ 42.433705] sctp_do_sm+0x28e7/0x6dd0 [ 42.437488] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 42.443519] ? print_irqtrace_events+0x270/0x270 [ 42.448241] ? __lock_acquire+0x6aa/0x3d50 [ 42.452447] ? print_irqtrace_events+0x270/0x270 [ 42.457186] ? find_held_lock+0x35/0x1d0 [ 42.461221] ? skb_dequeue+0x12a/0x180 [ 42.465079] ? lock_downgrade+0x990/0x990 [ 42.469197] ? do_raw_spin_trylock+0x190/0x190 [ 42.473751] ? mark_held_locks+0xaf/0x100 [ 42.477874] ? trace_hardirqs_on+0xd/0x10 [ 42.481996] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 42.486551] sctp_close+0x3c6/0x980 [ 42.490153] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 42.495394] ? __lock_acquire+0x6aa/0x3d50 [ 42.499598] ? check_noncircular+0x20/0x20 [ 42.503804] ? __lock_acquire+0x6aa/0x3d50 [ 42.508004] ? check_noncircular+0x20/0x20 [ 42.513374] ? locks_remove_file+0x3fa/0x5a0 [ 42.517752] ? fcntl_setlk+0x10c0/0x10c0 [ 42.521787] ? __fsnotify_parent+0xb4/0x3a0 [ 42.526079] ? ip_mc_drop_socket+0x1ce/0x230 [ 42.530461] inet_release+0xed/0x1c0 [ 42.534148] sock_release+0x8d/0x1e0 [ 42.537835] ? sock_release+0x1e0/0x1e0 [ 42.541775] sock_close+0x16/0x20 [ 42.545202] __fput+0x327/0x7e0 [ 42.548456] ? fput+0x140/0x140 [ 42.551708] ? _raw_spin_unlock_irq+0x27/0x70 [ 42.556184] ____fput+0x15/0x20 [ 42.559432] task_work_run+0x199/0x270 [ 42.563292] ? task_work_cancel+0x210/0x210 [ 42.567585] ? __do_page_fault+0x3d6/0xd60 [ 42.571795] get_signal+0x1343/0x16d0 [ 42.575565] ? mm_fault_error+0x2c0/0x2c0 [ 42.579683] ? ptrace_notify+0x130/0x130 [ 42.583714] ? check_noncircular+0x20/0x20 [ 42.587918] ? __do_page_fault+0xd60/0xd60 [ 42.592116] ? do_page_fault+0xee/0x720 [ 42.596059] ? __do_page_fault+0xd60/0xd60 [ 42.600263] ? check_noncircular+0x20/0x20 [ 42.604465] ? find_held_lock+0x35/0x1d0 [ 42.608496] ? retint_kernel+0x10/0x10 [ 42.612358] do_signal+0x94/0x1ee0 [ 42.615869] ? put_unused_fd+0x62/0x70 [ 42.619727] ? lock_downgrade+0x990/0x990 [ 42.623843] ? setup_sigcontext+0x7d0/0x7d0 [ 42.628131] ? do_raw_spin_trylock+0x190/0x190 [ 42.632683] ? __put_unused_fd+0x183/0x250 [ 42.636884] ? alloc_fdtable+0x280/0x280 [ 42.640914] ? cpumask_weight.constprop.3+0x45/0x45 [ 42.645899] ? _copy_to_user+0xa2/0xc0 [ 42.649756] ? _raw_spin_unlock+0x22/0x30 [ 42.653870] ? fput+0xd2/0x140 [ 42.657031] ? SYSC_accept4+0x4ec/0x850 [ 42.660977] ? exit_to_usermode_loop+0x8c/0x310 [ 42.665627] exit_to_usermode_loop+0x214/0x310 [ 42.670185] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 42.675688] ? _raw_spin_unlock_irq+0x27/0x70 [ 42.680155] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 42.685143] syscall_return_slowpath+0x42f/0x510 [ 42.689864] ? finish_task_switch+0x1aa/0x740 [ 42.694327] ? prepare_exit_to_usermode+0x2d0/0x2d0 [ 42.699313] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 42.704210] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 42.709194] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 42.713926] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 42.718647] RIP: 0033:0x445e39 [ 42.721804] RSP: 002b:00007fb1cbcb1dc8 EFLAGS: 00000202 ORIG_RAX: 0000000000000120 [ 42.729480] RAX: fffffffffffffff2 RBX: 0000000000000000 RCX: 0000000000445e39 [ 42.736716] RDX: 0000000020137ffc RSI: 0000000020b53ff0 RDI: 0000000000000003 [ 42.743953] RBP: 0000000000000000 R08: 00007fb1cbcb2700 R09: 00007fb1cbcb2700 [ 42.751191] R10: 0000000000080000 R11: 0000000000000202 R12: 0000000000000000 [ 42.758427] R13: 00000000007efe6f R14: 00007fb1cbcb29c0 R15: 0000000000000000 [ 42.765823] Dumping ftrace buffer: [ 42.769379] (ftrace buffer empty) [ 42.773060] Kernel Offset: disabled [ 42.776658] Rebooting in 86400 seconds..