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-7,10.128.0.27' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 56.079185] refcount_t: underflow; use-after-free. [ 56.080143] ------------[ cut here ]------------ [ 56.080789] WARNING: CPU: 1 PID: 3019 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 56.081948] Kernel panic - not syncing: panic_on_warn set ... [ 56.081948] [ 56.082923] CPU: 1 PID: 3019 Comm: syzkaller909903 Not tainted 4.13.0-rc7+ #56 [ 56.083889] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 56.085190] Call Trace: [ 56.085575] dump_stack+0x194/0x257 [ 56.086081] ? arch_local_irq_restore+0x53/0x53 [ 56.086712] panic+0x1e4/0x417 [ 56.087145] ? __warn+0x1d9/0x1d9 [ 56.087611] ? show_regs_print_info+0x65/0x65 [ 56.088258] ? retint_kernel+0x10/0x10 [ 56.088785] ? refcount_sub_and_test+0x167/0x1b0 [ 56.089428] __warn+0x1c4/0x1d9 [ 56.089870] ? refcount_sub_and_test+0x169/0x1b0 [ 56.090516] ? refcount_sub_and_test+0x167/0x1b0 [ 56.091186] report_bug+0x211/0x2d0 [ 56.091708] fixup_bug+0x40/0x90 [ 56.092180] do_trap+0x260/0x390 [ 56.092640] do_error_trap+0x120/0x390 [ 56.093164] ? do_trap+0x390/0x390 [ 56.093641] ? refcount_sub_and_test+0x167/0x1b0 [ 56.094271] ? vprintk_emit+0x3ea/0x590 [ 56.094812] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 56.095471] do_invalid_op+0x1b/0x20 [ 56.095981] invalid_op+0x1e/0x30 [ 56.096443] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 56.097231] RSP: 0018:ffff8801d0d56330 EFLAGS: 00010286 [ 56.097964] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 56.099034] RDX: 0000000000000026 RSI: 1ffff1003a1aac26 RDI: ffffed003a1aac5a [ 56.104626] RBP: ffff8801d0d563c0 R08: 0000000000000001 R09: 0000000000000000 [ 56.111870] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1003a1aac67 [ 56.119106] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801d23f59fc [ 56.126360] ? refcount_inc+0x50/0x50 [ 56.130127] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 56.134846] ? sctp_association_free+0x2d0/0x930 [ 56.139565] ? sctp_do_sm+0x28e7/0x6d90 [ 56.143504] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 56.148221] ? sctp_close+0x3c6/0x980 [ 56.151988] ? inet_release+0xed/0x1c0 [ 56.155845] sctp_wfree+0x183/0x620 [ 56.159437] ? __sctp_write_space+0x910/0x910 [ 56.163901] skb_release_head_state+0x124/0x200 [ 56.168539] skb_release_all+0x15/0x60 [ 56.172393] consume_skb+0x153/0x490 [ 56.176077] ? sctp_chunk_put+0x99/0x420 [ 56.180104] ? pskb_carve+0x1db0/0x1db0 [ 56.184052] ? sctp_chunk_hold+0x20/0x20 [ 56.188078] ? refcount_sub_and_test+0x115/0x1b0 [ 56.192801] ? refcount_inc+0x50/0x50 [ 56.196565] ? mark_held_locks+0xaf/0x100 [ 56.200689] ? sctp_datamsg_put+0x456/0x560 [ 56.204983] sctp_chunk_put+0x29c/0x420 [ 56.208928] ? sctp_chunk_hold+0x20/0x20 [ 56.212959] ? sctp_transport_dst_confirm+0x50/0x50 [ 56.217938] ? find_held_lock+0x35/0x1d0 [ 56.221982] sctp_chunk_free+0x53/0x60 [ 56.225839] __sctp_outq_teardown+0xc7d/0x15a0 [ 56.230395] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 56.235289] ? find_held_lock+0x35/0x1d0 [ 56.239334] ? print_usage_bug+0x480/0x480 [ 56.243536] ? do_raw_spin_trylock+0x190/0x190 [ 56.248085] ? print_usage_bug+0x480/0x480 [ 56.252300] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 56.257464] ? check_noncircular+0x20/0x20 [ 56.261666] ? print_usage_bug+0x480/0x480 [ 56.265863] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 56.271020] ? sock_destroy_inode+0x56/0x70 [ 56.275308] ? print_usage_bug+0x480/0x480 [ 56.279599] ? lock_acquire+0x1d5/0x580 [ 56.283551] ? lock_acquire+0x1d5/0x580 [ 56.287490] ? lock_timer_base+0x1a3/0x2b0 [ 56.291694] ? find_held_lock+0x35/0x1d0 [ 56.295736] ? sock_def_wakeup+0x1f9/0x350 [ 56.299938] ? lock_downgrade+0x990/0x990 [ 56.304053] ? lock_release+0xa40/0xa40 [ 56.307999] sctp_outq_free+0x15/0x20 [ 56.311766] sctp_association_free+0x2d0/0x930 [ 56.316320] ? sctp_asconf_queue_teardown+0x700/0x700 [ 56.321476] ? sock_def_wakeup+0x222/0x350 [ 56.325679] ? sk_dst_check+0x560/0x560 [ 56.329620] ? sctp_association_put+0x74/0x2f0 [ 56.334167] ? sctp_association_hold+0x20/0x20 [ 56.338716] ? find_held_lock+0x35/0x1d0 [ 56.342744] ? sctp_sm_lookup_event+0x95/0x3c0 [ 56.347294] sctp_do_sm+0x28e7/0x6d90 [ 56.351062] ? find_held_lock+0x35/0x1d0 [ 56.355096] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 56.361121] ? print_usage_bug+0x480/0x480 [ 56.365320] ? do_raw_spin_trylock+0x190/0x190 [ 56.369868] ? print_usage_bug+0x480/0x480 [ 56.374086] ? __kernel_text_address+0xae/0xe0 [ 56.378634] ? unwind_get_return_address+0x61/0xa0 [ 56.383534] ? find_held_lock+0x35/0x1d0 [ 56.387568] ? skb_dequeue+0x12a/0x180 [ 56.391439] ? lock_downgrade+0x990/0x990 [ 56.395610] ? do_raw_spin_trylock+0x190/0x190 [ 56.400169] ? mark_held_locks+0xaf/0x100 [ 56.404290] ? trace_hardirqs_on+0xd/0x10 [ 56.408411] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 56.412980] sctp_close+0x3c6/0x980 [ 56.416582] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 56.421827] ? dentry_free+0xcd/0x130 [ 56.425608] ? rcu_read_lock_sched_held+0x108/0x120 [ 56.430614] ? kmem_cache_free+0x249/0x280 [ 56.434833] ? dentry_free+0xd2/0x130 [ 56.438620] ? locks_remove_file+0x414/0x560 [ 56.443001] ? fcntl_setlk+0x10c0/0x10c0 [ 56.447044] ? __fsnotify_parent+0xb4/0x3a0 [ 56.451334] ? ip_mc_drop_socket+0x1ce/0x230 [ 56.455721] inet_release+0xed/0x1c0 [ 56.459408] sock_release+0x8d/0x1e0 [ 56.463090] ? sock_release+0x1e0/0x1e0 [ 56.467030] sock_close+0x16/0x20 [ 56.470451] __fput+0x327/0x7e0 [ 56.473706] ? fput+0x140/0x140 [ 56.476955] ? check_same_owner+0x320/0x320 [ 56.481242] ? do_raw_spin_trylock+0x190/0x190 [ 56.485791] ? check_same_owner+0x320/0x320 [ 56.490081] ____fput+0x15/0x20 [ 56.493329] task_work_run+0x18a/0x260 [ 56.497186] ? task_work_cancel+0x210/0x210 [ 56.501475] ? _raw_spin_unlock+0x22/0x30 [ 56.505589] ? switch_task_namespaces+0x87/0xc0 [ 56.510229] do_exit+0xa3a/0x1b10 [ 56.513649] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 56.518808] ? print_usage_bug+0x480/0x480 [ 56.523039] ? mm_update_next_owner+0x930/0x930 [ 56.527694] ? check_noncircular+0x20/0x20 [ 56.531898] ? check_noncircular+0x20/0x20 [ 56.536102] ? find_held_lock+0x35/0x1d0 [ 56.540133] ? find_held_lock+0x35/0x1d0 [ 56.544164] ? check_noncircular+0x20/0x20 [ 56.548364] ? check_noncircular+0x20/0x20 [ 56.552563] ? lock_downgrade+0x990/0x990 [ 56.556690] ? do_raw_spin_trylock+0x190/0x190 [ 56.561243] ? reacquire_held_locks+0x1fd/0x3d0 [ 56.565876] ? mark_held_locks+0xaf/0x100 [ 56.569994] ? reacquire_held_locks+0x1fd/0x3d0 [ 56.574631] ? check_noncircular+0x20/0x20 [ 56.578831] ? find_held_lock+0x35/0x1d0 [ 56.582865] ? release_sock+0x1d4/0x2a0 [ 56.586807] ? lock_downgrade+0x990/0x990 [ 56.590919] ? lock_downgrade+0x990/0x990 [ 56.595042] ? find_held_lock+0x35/0x1d0 [ 56.599074] ? get_signal+0x855/0x17e0 [ 56.602926] ? lock_downgrade+0x990/0x990 [ 56.607049] do_group_exit+0x149/0x400 [ 56.610902] ? __lock_is_held+0xb6/0x140 [ 56.614929] ? SyS_exit+0x30/0x30 [ 56.618348] ? _raw_spin_unlock_irq+0x27/0x70 [ 56.622809] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 56.627794] get_signal+0x7e8/0x17e0 [ 56.631501] ? ptrace_notify+0x130/0x130 [ 56.635527] ? inet_autobind+0x1f/0x180 [ 56.639466] ? __local_bh_enable_ip+0x9d/0x160 [ 56.644020] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 56.649008] ? release_sock+0x1d4/0x2a0 [ 56.652947] ? trace_hardirqs_on+0xd/0x10 [ 56.657061] ? __local_bh_enable_ip+0x9d/0x160 [ 56.661618] ? _raw_spin_unlock_bh+0x30/0x40 [ 56.665992] ? release_sock+0x1d4/0x2a0 [ 56.669937] ? __release_sock+0x360/0x360 [ 56.674052] ? trace_hardirqs_on+0xd/0x10 [ 56.678171] do_signal+0x94/0x1ee0 [ 56.681680] ? inet_sendmsg+0x11f/0x5e0 [ 56.685618] ? inet_sendmsg+0x126/0x5e0 [ 56.689556] ? __might_sleep+0x95/0x190 [ 56.693500] ? setup_sigcontext+0x7d0/0x7d0 [ 56.697785] ? selinux_socket_sendmsg+0x36/0x40 [ 56.702420] ? security_socket_sendmsg+0x89/0xb0 [ 56.707140] ? inet_recvmsg+0x5f0/0x5f0 [ 56.711080] ? sock_sendmsg+0x4f/0x110 [ 56.714935] ? fput+0xd2/0x140 [ 56.718096] ? SYSC_sendto+0x40d/0x5a0 [ 56.721954] ? SYSC_connect+0x470/0x470 [ 56.725897] ? find_held_lock+0x35/0x1d0 [ 56.729928] ? exit_to_usermode_loop+0x98/0x300 [ 56.734569] exit_to_usermode_loop+0x224/0x300 [ 56.739121] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 56.744719] ? handle_mm_fault+0x4a2/0x860 [ 56.748916] ? down_read_trylock+0xdb/0x170 [ 56.753215] syscall_return_slowpath+0x3a7/0x450 [ 56.757937] ? prepare_exit_to_usermode+0x220/0x220 [ 56.762921] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 56.767816] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 56.772797] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 56.777524] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 56.782244] RIP: 0033:0x4473f9 [ 56.785402] RSP: 002b:00007fe962579db8 EFLAGS: 00000212 ORIG_RAX: 000000000000002c [ 56.793078] RAX: 000000000000001a RBX: 0000000000000000 RCX: 00000000004473f9 [ 56.800316] RDX: 000000000000001a RSI: 0000000020b54fe6 RDI: 0000000000000005 [ 56.807552] RBP: 0000000000000000 R08: 0000000020b54000 R09: 0000000000000010 [ 56.814788] R10: 0000000000000004 R11: 0000000000000212 R12: 0000000000000000 [ 56.822023] R13: 00000000007efd5f R14: 00007fe96257a9c0 R15: 0000000000000000 [ 56.829415] Dumping ftrace buffer: [ 56.832968] (ftrace buffer empty) [ 56.836648] Kernel Offset: disabled [ 56.840245] Rebooting in 86400 seconds..