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-386-3,10.128.15.196' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 48.939775] refcount_t: underflow; use-after-free. [ 48.945127] ------------[ cut here ]------------ [ 48.949914] WARNING: CPU: 0 PID: 2997 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 48.958585] Kernel panic - not syncing: panic_on_warn set ... [ 48.958585] [ 48.965920] CPU: 0 PID: 2997 Comm: syzkaller872394 Not tainted 4.14.0-rc3+ #27 [ 48.973245] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.982573] Call Trace: [ 48.985141] dump_stack+0x194/0x257 [ 48.988748] ? arch_local_irq_restore+0x53/0x53 [ 48.993402] panic+0x1e4/0x417 [ 48.996573] ? __warn+0x1d9/0x1d9 [ 48.999999] ? show_regs_print_info+0x65/0x65 [ 49.004471] ? retint_kernel+0x10/0x10 [ 49.008340] ? refcount_sub_and_test+0x167/0x1b0 [ 49.013067] __warn+0x1c4/0x1d9 [ 49.016318] ? refcount_sub_and_test+0x167/0x1b0 [ 49.021050] report_bug+0x211/0x2d0 [ 49.024657] fixup_bug+0x40/0x90 [ 49.028000] do_trap+0x260/0x390 [ 49.031347] do_error_trap+0x120/0x390 [ 49.035209] ? do_trap+0x390/0x390 [ 49.038720] ? refcount_sub_and_test+0x167/0x1b0 [ 49.043448] ? vprintk_emit+0x3ea/0x590 [ 49.047401] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 49.052221] do_invalid_op+0x1b/0x20 [ 49.055907] invalid_op+0x18/0x20 [ 49.059329] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 49.064675] RSP: 0018:ffff8801d5506390 EFLAGS: 00010286 [ 49.070010] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 49.077247] RDX: 0000000000000026 RSI: 1ffff1003aaa0c32 RDI: ffffed003aaa0c66 [ 49.084487] RBP: ffff8801d5506420 R08: ffff8801d5505a80 R09: 0000000000000000 [ 49.091728] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1003aaa0c73 [ 49.098968] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801cf578a24 [ 49.106233] ? refcount_inc+0x50/0x50 [ 49.110008] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 49.114732] ? sctp_association_free+0x2d0/0x930 [ 49.119456] ? sctp_do_sm+0x28e7/0x6dd0 [ 49.123398] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 49.128120] ? sctp_close+0x3c6/0x980 [ 49.131890] ? inet_release+0xed/0x1c0 [ 49.135752] sctp_wfree+0x183/0x620 [ 49.139348] ? __sctp_write_space+0x910/0x910 [ 49.143820] skb_release_head_state+0x124/0x200 [ 49.148459] skb_release_all+0x15/0x60 [ 49.152316] consume_skb+0x153/0x490 [ 49.155999] ? sctp_chunk_put+0x99/0x420 [ 49.160032] ? alloc_skb_with_frags+0x710/0x710 [ 49.164674] ? sctp_chunk_hold+0x20/0x20 [ 49.168708] ? refcount_sub_and_test+0x115/0x1b0 [ 49.173432] ? refcount_inc+0x50/0x50 [ 49.177202] ? mark_held_locks+0xb2/0x100 [ 49.181320] ? sctp_datamsg_put+0x456/0x560 [ 49.185618] sctp_chunk_put+0x29c/0x420 [ 49.189562] ? sctp_chunk_hold+0x20/0x20 [ 49.193596] ? sctp_transport_dst_confirm+0x50/0x50 [ 49.198583] ? unwind_dump+0x4c0/0x4c0 [ 49.202445] ? unwind_dump+0x4c0/0x4c0 [ 49.206314] sctp_chunk_free+0x53/0x60 [ 49.210172] __sctp_outq_teardown+0xc7d/0x15a0 [ 49.214724] ? sock_release+0x8d/0x1e0 [ 49.218587] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 49.223486] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 49.228473] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 49.233458] ? unwind_dump+0x4c0/0x4c0 [ 49.237311] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 49.242298] ? unwind_dump+0x4c0/0x4c0 [ 49.246168] ? check_noncircular+0x20/0x20 [ 49.250374] ? check_noncircular+0x20/0x20 [ 49.254575] ? unwind_get_return_address+0x61/0xa0 [ 49.259476] ? __save_stack_trace+0x61/0xd0 [ 49.263770] ? check_noncircular+0x20/0x20 [ 49.267978] ? print_usage_bug+0x480/0x480 [ 49.272189] ? find_held_lock+0x39/0x1d0 [ 49.276233] ? lock_downgrade+0x990/0x990 [ 49.280357] ? sk_dst_check+0x560/0x560 [ 49.284301] ? rcu_read_lock_sched_held+0x108/0x120 [ 49.289290] ? lock_release+0xd70/0xd70 [ 49.293242] sctp_outq_free+0x15/0x20 [ 49.297010] sctp_association_free+0x2d0/0x930 [ 49.301565] ? sctp_asconf_queue_teardown+0x700/0x700 [ 49.306726] ? sock_def_wakeup+0x222/0x350 [ 49.310931] ? sk_dst_check+0x560/0x560 [ 49.314874] ? sctp_association_put+0x74/0x2f0 [ 49.319423] ? sctp_association_hold+0x20/0x20 [ 49.323976] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 49.329135] ? find_held_lock+0x39/0x1d0 [ 49.333172] sctp_do_sm+0x28e7/0x6dd0 [ 49.336957] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 49.342996] ? print_usage_bug+0x480/0x480 [ 49.347209] ? do_raw_spin_trylock+0x190/0x190 [ 49.351769] ? print_usage_bug+0x480/0x480 [ 49.355981] ? find_held_lock+0x39/0x1d0 [ 49.360024] ? lock_downgrade+0x990/0x990 [ 49.364149] ? skb_dequeue+0x22/0x180 [ 49.367928] ? do_raw_spin_trylock+0x190/0x190 [ 49.372483] ? mark_held_locks+0xb2/0x100 [ 49.376609] ? trace_hardirqs_on+0xd/0x10 [ 49.380737] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 49.385292] sctp_close+0x3c6/0x980 [ 49.388898] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 49.394144] ? dentry_free+0xcd/0x130 [ 49.397914] ? rcu_read_lock_sched_held+0x108/0x120 [ 49.402900] ? kmem_cache_free+0x249/0x280 [ 49.407107] ? dentry_free+0xd2/0x130 [ 49.410884] ? locks_remove_file+0x3fa/0x5a0 [ 49.415268] ? fcntl_setlk+0x10d0/0x10d0 [ 49.419301] ? __fsnotify_parent+0xb4/0x3a0 [ 49.423591] ? ip_mc_drop_socket+0x1ce/0x230 [ 49.427975] inet_release+0xed/0x1c0 [ 49.431663] sock_release+0x8d/0x1e0 [ 49.435346] ? sock_release+0x1e0/0x1e0 [ 49.439289] sock_close+0x16/0x20 [ 49.442712] __fput+0x333/0x7f0 [ 49.445982] ? fput+0x140/0x140 [ 49.449235] ? check_same_owner+0x320/0x320 [ 49.453531] ____fput+0x15/0x20 [ 49.456788] task_work_run+0x199/0x270 [ 49.460656] ? task_work_cancel+0x210/0x210 [ 49.464946] ? free_nsproxy+0x185/0x1f0 [ 49.468893] ? switch_task_namespaces+0xa2/0xc0 [ 49.473538] do_exit+0x9d2/0x1af0 [ 49.476971] ? mm_update_next_owner+0x930/0x930 [ 49.481610] ? save_stack_trace+0x16/0x20 [ 49.485726] ? __lock_acquire+0x20fd/0x4620 [ 49.490019] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 49.495205] ? check_noncircular+0x20/0x20 [ 49.499415] ? trace_hardirqs_on_caller+0x19e/0x5c0 [ 49.504405] ? trace_hardirqs_on+0xd/0x10 [ 49.508526] ? __wake_up_common_lock+0x1c2/0x310 [ 49.514157] ? check_noncircular+0x20/0x20 [ 49.518369] ? find_held_lock+0x39/0x1d0 [ 49.522414] ? lock_downgrade+0x990/0x990 [ 49.526533] ? recalc_sigpending_tsk+0x117/0x150 [ 49.531262] ? recalc_sigpending+0x103/0x160 [ 49.535654] ? recalc_sigpending_tsk+0x150/0x150 [ 49.540378] ? get_signal+0x2b2/0x16d0 [ 49.544246] do_group_exit+0x149/0x400 [ 49.548103] ? __lock_is_held+0xbc/0x140 [ 49.552134] ? SyS_exit+0x30/0x30 [ 49.555560] ? _raw_spin_unlock_irq+0x27/0x70 [ 49.560029] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 49.565019] get_signal+0x73f/0x16d0 [ 49.568713] ? ptrace_notify+0x130/0x130 [ 49.572753] ? __fd_install+0x2f7/0x6a0 [ 49.576699] ? __might_fault+0xe0/0x1d0 [ 49.580648] ? get_unused_fd_flags+0x190/0x190 [ 49.585213] do_signal+0x94/0x1ee0 [ 49.588722] ? __might_sleep+0x95/0x190 [ 49.592679] ? __might_fault+0x188/0x1d0 [ 49.596714] ? setup_sigcontext+0x7d0/0x7d0 [ 49.601004] ? fput+0xd2/0x140 [ 49.604169] ? SYSC_accept4+0x4f2/0x850 [ 49.608119] ? kernel_accept+0x2f0/0x2f0 [ 49.612159] ? handle_mm_fault+0x410/0x8d0 [ 49.616362] ? down_read_trylock+0xdb/0x170 [ 49.620652] ? __do_page_fault+0x31e/0xd60 [ 49.624859] ? __handle_mm_fault+0x39c0/0x39c0 [ 49.629409] ? vmacache_find+0x5f/0x280 [ 49.633354] ? vmacache_update+0xfe/0x130 [ 49.637471] ? exit_to_usermode_loop+0x8c/0x310 [ 49.642119] exit_to_usermode_loop+0x214/0x310 [ 49.646759] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 49.652279] do_fast_syscall_32+0x83e/0xf05 [ 49.656576] ? do_int80_syscall_32+0x940/0x940 [ 49.661133] ? lockdep_sys_exit+0x47/0xf0 [ 49.665249] ? syscall_return_slowpath+0x2b3/0x510 [ 49.670152] ? finish_task_switch+0x1aa/0x740 [ 49.674621] ? retint_user+0x18/0x20 [ 49.678310] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 49.683128] entry_SYSENTER_compat+0x51/0x60 [ 49.687504] RIP: 0023:0xf7fecc79 [ 49.690839] RSP: 002b:00000000f67e51ec EFLAGS: 00000296 ORIG_RAX: 000000000000016c [ 49.698520] RAX: 0000000000000004 RBX: 0000000000000003 RCX: 0000000020000000 [ 49.705931] RDX: 0000000020146ffc RSI: 0000000000000800 RDI: 0000000000000000 [ 49.713171] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 49.720409] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 49.727647] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 49.735040] Dumping ftrace buffer: [ 49.738590] (ftrace buffer empty) [ 49.742269] Kernel Offset: disabled [ 49.745874] Rebooting in 86400 seconds..