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-386-1,10.128.0.37' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 48.131645] refcount_t: underflow; use-after-free. [ 48.132563] ------------[ cut here ]------------ [ 48.133424] WARNING: CPU: 1 PID: 2991 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 48.134576] Kernel panic - not syncing: panic_on_warn set ... [ 48.134576] [ 48.135586] CPU: 1 PID: 2991 Comm: syzkaller376549 Not tainted 4.14.0-rc6+ #55 [ 48.136585] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.137803] Call Trace: [ 48.138162] dump_stack+0x194/0x257 [ 48.138665] ? arch_local_irq_restore+0x53/0x53 [ 48.139298] panic+0x1e4/0x417 [ 48.139731] ? __warn+0x1d9/0x1d9 [ 48.140197] ? show_regs_print_info+0x65/0x65 [ 48.140809] ? refcount_sub_and_test+0x167/0x1b0 [ 48.141451] __warn+0x1c4/0x1d9 [ 48.141895] ? refcount_sub_and_test+0x167/0x1b0 [ 48.142530] report_bug+0x211/0x2d0 [ 48.143028] fixup_bug+0x40/0x90 [ 48.143485] do_trap+0x260/0x390 [ 48.143946] do_error_trap+0x120/0x390 [ 48.144477] ? vprintk_emit+0x49b/0x590 [ 48.145017] ? do_trap+0x390/0x390 [ 48.145494] ? refcount_sub_and_test+0x167/0x1b0 [ 48.146125] ? vprintk_emit+0x3ea/0x590 [ 48.146673] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 48.147323] do_invalid_op+0x1b/0x20 [ 48.147836] invalid_op+0x18/0x20 [ 48.148300] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 48.149012] RSP: 0018:ffff8801d1e46858 EFLAGS: 00010286 [ 48.149737] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 48.150714] RDX: 0000000000000026 RSI: 1ffff1003a3c8ccb RDI: ffffed003a3c8cff [ 48.151685] RBP: ffff8801d1e468e8 R08: 0000000000000001 R09: 0000000000000000 [ 48.158269] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1003a3c8d0c [ 48.165504] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801d2bda2bc [ 48.172757] ? refcount_sub_and_test+0x167/0x1b0 [ 48.177480] ? refcount_inc+0x50/0x50 [ 48.181251] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 48.185971] ? sctp_association_free+0x2d0/0x930 [ 48.190703] ? sctp_do_sm+0x28e7/0x6dd0 [ 48.194644] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 48.199366] ? sctp_close+0x3c6/0x980 [ 48.203136] ? inet_release+0xed/0x1c0 [ 48.206993] sctp_wfree+0x183/0x620 [ 48.210588] ? __sctp_write_space+0x910/0x910 [ 48.215052] skb_release_head_state+0x124/0x200 [ 48.219690] skb_release_all+0x15/0x60 [ 48.223545] consume_skb+0x153/0x490 [ 48.227223] ? sctp_chunk_put+0x99/0x420 [ 48.231250] ? alloc_skb_with_frags+0x710/0x710 [ 48.235885] ? sctp_chunk_hold+0x20/0x20 [ 48.239916] ? refcount_sub_and_test+0x115/0x1b0 [ 48.244641] ? refcount_inc+0x50/0x50 [ 48.248411] ? mark_held_locks+0xaf/0x100 [ 48.252528] ? sctp_datamsg_put+0x456/0x560 [ 48.256822] sctp_chunk_put+0x29c/0x420 [ 48.260764] ? sctp_chunk_hold+0x20/0x20 [ 48.264795] ? sctp_transport_dst_confirm+0x50/0x50 [ 48.269777] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 48.274932] ? lock_release+0xa40/0xa40 [ 48.278880] ? show_initstate+0xb0/0xb0 [ 48.282824] sctp_chunk_free+0x53/0x60 [ 48.286679] __sctp_outq_teardown+0xc7d/0x15a0 [ 48.291235] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 48.296139] ? rcutorture_record_progress+0x10/0x10 [ 48.301133] ? is_bpf_text_address+0xa4/0x120 [ 48.305596] ? kernel_text_address+0x102/0x140 [ 48.310146] ? __kernel_text_address+0xd/0x40 [ 48.314609] ? unwind_get_return_address+0x61/0xa0 [ 48.319507] ? __save_stack_trace+0x7e/0xd0 [ 48.323802] ? add_lock_to_list.isra.33+0x292/0x39b [ 48.328792] ? check_noncircular+0x20/0x20 [ 48.332997] ? print_irqtrace_events+0x270/0x270 [ 48.337732] ? check_noncircular+0x20/0x20 [ 48.341942] ? lock_acquire+0x1d5/0x580 [ 48.345881] ? lock_acquire+0x1d5/0x580 [ 48.349822] ? lock_timer_base+0x1a3/0x2b0 [ 48.354026] ? find_held_lock+0x35/0x1d0 [ 48.358060] ? sock_def_wakeup+0x1f9/0x350 [ 48.362260] ? lock_downgrade+0x990/0x990 [ 48.366378] ? lock_release+0xa40/0xa40 [ 48.370324] sctp_outq_free+0x15/0x20 [ 48.374089] sctp_association_free+0x2d0/0x930 [ 48.378640] ? sctp_asconf_queue_teardown+0x700/0x700 [ 48.383796] ? sock_def_wakeup+0x222/0x350 [ 48.388000] ? sk_dst_check+0x560/0x560 [ 48.391941] ? sctp_association_put+0x74/0x2f0 [ 48.396488] ? sctp_association_hold+0x20/0x20 [ 48.401034] ? lock_downgrade+0x990/0x990 [ 48.405159] sctp_do_sm+0x28e7/0x6dd0 [ 48.408939] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 48.414965] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 48.420123] ? print_irqtrace_events+0x270/0x270 [ 48.424843] ? __lock_acquire+0x6aa/0x3d50 [ 48.429045] ? print_irqtrace_events+0x270/0x270 [ 48.433768] ? check_usage_backwards+0x20a/0x420 [ 48.438503] ? find_held_lock+0x35/0x1d0 [ 48.442536] ? skb_dequeue+0x12a/0x180 [ 48.446390] ? lock_downgrade+0x990/0x990 [ 48.450521] ? do_raw_spin_trylock+0x190/0x190 [ 48.455073] ? mark_held_locks+0xaf/0x100 [ 48.459198] ? trace_hardirqs_on+0xd/0x10 [ 48.463319] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 48.467873] sctp_close+0x3c6/0x980 [ 48.471464] ? check_noncircular+0x20/0x20 [ 48.475672] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 48.480916] ? check_noncircular+0x20/0x20 [ 48.485116] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 48.490272] ? search_extable+0x35/0x40 [ 48.494222] ? copy_user_handle_tail+0x40/0x80 [ 48.498771] ? ex_handler_default+0x18/0x90 [ 48.503056] ? __pte+0x60/0x60 [ 48.506220] ? locks_remove_file+0x3fa/0x5a0 [ 48.510597] ? fcntl_setlk+0x10c0/0x10c0 [ 48.514628] ? __fsnotify_parent+0xb4/0x3a0 [ 48.518919] ? ip_mc_drop_socket+0x1ce/0x230 [ 48.523300] inet_release+0xed/0x1c0 [ 48.526984] sock_release+0x8d/0x1e0 [ 48.530663] ? sock_release+0x1e0/0x1e0 [ 48.534620] sock_close+0x16/0x20 [ 48.538042] __fput+0x327/0x7e0 [ 48.541295] ? fput+0x140/0x140 [ 48.544545] ? _raw_spin_unlock_irq+0x27/0x70 [ 48.549024] ____fput+0x15/0x20 [ 48.552270] task_work_run+0x199/0x270 [ 48.556128] ? task_work_cancel+0x210/0x210 [ 48.560418] ? check_noncircular+0x20/0x20 [ 48.564618] ? __do_page_fault+0xd60/0xd60 [ 48.568819] ? do_page_fault+0xee/0x720 [ 48.572763] get_signal+0x1343/0x16d0 [ 48.576532] ? check_noncircular+0x20/0x20 [ 48.580732] ? find_held_lock+0x35/0x1d0 [ 48.584772] ? ptrace_notify+0x130/0x130 [ 48.588801] ? find_held_lock+0x35/0x1d0 [ 48.592838] ? put_unused_fd+0x62/0x70 [ 48.596692] ? lock_downgrade+0x990/0x990 [ 48.600809] ? do_raw_spin_trylock+0x190/0x190 [ 48.605363] do_signal+0x94/0x1ee0 [ 48.608867] ? alloc_fdtable+0x280/0x280 [ 48.612891] ? cpumask_weight.constprop.3+0x45/0x45 [ 48.618320] ? _copy_to_user+0xa2/0xc0 [ 48.622186] ? setup_sigcontext+0x7d0/0x7d0 [ 48.626473] ? fput+0xd2/0x140 [ 48.629638] ? SYSC_accept4+0x4ec/0x850 [ 48.633583] ? kernel_accept+0x2f0/0x2f0 [ 48.637628] ? handle_mm_fault+0x410/0x8d0 [ 48.641830] ? down_read_trylock+0xdb/0x170 [ 48.646116] ? __do_page_fault+0x31e/0xd60 [ 48.650318] ? __handle_mm_fault+0x39c0/0x39c0 [ 48.654866] ? vmacache_find+0x5f/0x280 [ 48.658815] ? vmacache_update+0xfe/0x130 [ 48.662934] ? exit_to_usermode_loop+0x8c/0x310 [ 48.667574] exit_to_usermode_loop+0x214/0x310 [ 48.672128] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 48.677644] do_fast_syscall_32+0x83e/0xf05 [ 48.681950] ? do_int80_syscall_32+0x940/0x940 [ 48.686504] ? syscall_return_slowpath+0x2b3/0x510 [ 48.691400] ? finish_task_switch+0x1aa/0x740 [ 48.695864] ? prepare_exit_to_usermode+0x2d0/0x2d0 [ 48.700850] ? retint_user+0x18/0x20 [ 48.704534] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 48.709348] entry_SYSENTER_compat+0x51/0x60 [ 48.713721] RIP: 0023:0xf7f97c79 [ 48.717053] RSP: 002b:00000000f67901ec EFLAGS: 00000296 ORIG_RAX: 000000000000016c [ 48.724813] RAX: fffffffffffffff2 RBX: 0000000000000003 RCX: 0000000020b53ff0 [ 48.732050] RDX: 0000000020137ffc RSI: 0000000000080000 RDI: 0000000000000000 [ 48.739287] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 48.746532] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 48.753766] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 48.761212] Dumping ftrace buffer: [ 48.764779] (ftrace buffer empty) [ 48.768457] Kernel Offset: disabled [ 48.772057] Rebooting in 86400 seconds..