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-mmots-kasan-gce-0,10.128.15.192' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 30.494660] refcount_t: underflow; use-after-free. [ 30.499740] ------------[ cut here ]------------ [ 30.504599] WARNING: CPU: 0 PID: 2988 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 30.513257] Kernel panic - not syncing: panic_on_warn set ... [ 30.513257] [ 30.520604] CPU: 0 PID: 2988 Comm: syzkaller140459 Not tainted 4.13.0-mm1+ #7 [ 30.527843] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.537182] Call Trace: [ 30.539745] dump_stack+0x194/0x257 [ 30.543352] ? arch_local_irq_restore+0x53/0x53 [ 30.548004] panic+0x1e4/0x417 [ 30.551171] ? __warn+0x1d9/0x1d9 [ 30.554593] ? show_regs_print_info+0x65/0x65 [ 30.559072] ? refcount_sub_and_test+0x167/0x1b0 [ 30.563797] __warn+0x1c4/0x1d9 [ 30.567051] ? refcount_sub_and_test+0x167/0x1b0 [ 30.571787] report_bug+0x211/0x2d0 [ 30.575404] fixup_bug+0x40/0x90 [ 30.578747] do_trap+0x260/0x390 [ 30.582094] do_error_trap+0x120/0x390 [ 30.585960] ? do_trap+0x390/0x390 [ 30.589473] ? refcount_sub_and_test+0x167/0x1b0 [ 30.594202] ? vprintk_emit+0x3ea/0x590 [ 30.598157] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 30.602982] do_invalid_op+0x1b/0x20 [ 30.606686] invalid_op+0x18/0x20 [ 30.610127] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 30.615456] RSP: 0018:ffff8801ce536920 EFLAGS: 00010286 [ 30.620792] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 30.628031] RDX: 0000000000000026 RSI: 1ffff10039ca6ce4 RDI: ffffed0039ca6d18 [ 30.635284] RBP: ffff8801ce5369b0 R08: ffff8801ce536010 R09: 0000000000000000 [ 30.642524] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff10039ca6d25 [ 30.649777] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801d28deae4 [ 30.657044] ? refcount_inc+0x50/0x50 [ 30.660816] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 30.665540] ? sctp_association_free+0x2d0/0x930 [ 30.670277] ? sctp_do_sm+0x28e7/0x6dd0 [ 30.674223] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 30.678947] ? sctp_close+0x3c6/0x980 [ 30.682718] ? inet_release+0xed/0x1c0 [ 30.686581] sctp_wfree+0x183/0x620 [ 30.690180] ? __sctp_write_space+0x910/0x910 [ 30.694656] skb_release_head_state+0x124/0x200 [ 30.699298] skb_release_all+0x15/0x60 [ 30.703159] consume_skb+0x153/0x490 [ 30.706842] ? sctp_chunk_put+0x99/0x420 [ 30.710882] ? alloc_skb_with_frags+0x710/0x710 [ 30.715523] ? sctp_chunk_hold+0x20/0x20 [ 30.719558] ? refcount_sub_and_test+0x115/0x1b0 [ 30.724286] ? refcount_inc+0x50/0x50 [ 30.728062] ? mark_held_locks+0xb2/0x100 [ 30.732183] ? sctp_datamsg_put+0x456/0x560 [ 30.736481] sctp_chunk_put+0x29c/0x420 [ 30.740427] ? sctp_chunk_hold+0x20/0x20 [ 30.744463] ? sctp_transport_dst_confirm+0x50/0x50 [ 30.749470] sctp_chunk_free+0x53/0x60 [ 30.753332] __sctp_outq_teardown+0xc7d/0x15a0 [ 30.757888] ? inet6_release+0x50/0x70 [ 30.761755] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 30.766660] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 30.771663] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 30.776652] ? unwind_dump+0x4c0/0x4c0 [ 30.780514] ? unwind_dump+0x4c0/0x4c0 [ 30.784378] ? copy_trace+0x1d0/0x1d0 [ 30.788155] ? check_noncircular+0x20/0x20 [ 30.792363] ? check_noncircular+0x20/0x20 [ 30.796569] ? unwind_get_return_address+0x61/0xa0 [ 30.801472] ? __save_stack_trace+0x61/0xd0 [ 30.805779] ? check_noncircular+0x20/0x20 [ 30.810005] ? print_usage_bug+0x480/0x480 [ 30.814236] ? find_held_lock+0x39/0x1d0 [ 30.818280] ? lock_downgrade+0x990/0x990 [ 30.822411] ? sk_dst_check+0x560/0x560 [ 30.826366] ? rcu_read_lock_sched_held+0x108/0x120 [ 30.831363] ? lock_release+0xd70/0xd70 [ 30.835320] sctp_outq_free+0x15/0x20 [ 30.839096] sctp_association_free+0x2d0/0x930 [ 30.843656] ? sctp_asconf_queue_teardown+0x700/0x700 [ 30.848822] ? sock_def_wakeup+0x222/0x350 [ 30.853029] ? sk_dst_check+0x560/0x560 [ 30.856978] ? sctp_association_put+0x74/0x2f0 [ 30.861542] ? sctp_association_hold+0x20/0x20 [ 30.866102] ? unwind_dump+0x4c0/0x4c0 [ 30.869966] ? sctp_sm_lookup_event+0x95/0x3c0 [ 30.874543] sctp_do_sm+0x28e7/0x6dd0 [ 30.878331] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 30.884369] ? print_usage_bug+0x480/0x480 [ 30.888584] ? __lock_acquire+0x20fd/0x4620 [ 30.892881] ? print_usage_bug+0x480/0x480 [ 30.897094] ? find_held_lock+0x39/0x1d0 [ 30.901141] ? lock_downgrade+0x990/0x990 [ 30.905272] ? skb_dequeue+0x22/0x180 [ 30.909054] ? do_raw_spin_trylock+0x190/0x190 [ 30.913637] ? mark_held_locks+0xb2/0x100 [ 30.917769] ? trace_hardirqs_on+0xd/0x10 [ 30.921898] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 30.926459] sctp_close+0x3c6/0x980 [ 30.930066] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 30.935316] ? unwind_get_return_address+0x61/0xa0 [ 30.940222] ? check_noncircular+0x20/0x20 [ 30.944441] ? depot_save_stack+0x12c/0x490 [ 30.948743] ? ipv6_sock_ac_close+0x2e8/0x3e0 [ 30.953217] ? ipv6_sock_mc_close+0x148/0x1a0 [ 30.957686] ? ipv6_sock_ac_drop+0x580/0x580 [ 30.962081] ? ip_mc_drop_socket+0x1ce/0x230 [ 30.966469] ? __fsnotify_parent+0xb4/0x3a0 [ 30.970767] inet_release+0xed/0x1c0 [ 30.974460] inet6_release+0x50/0x70 [ 30.978153] sock_release+0x8d/0x1e0 [ 30.981849] ? sock_release+0x1e0/0x1e0 [ 30.985799] sock_close+0x16/0x20 [ 30.989239] __fput+0x333/0x7f0 [ 30.992498] ? fput+0x140/0x140 [ 30.995754] ? _raw_spin_unlock_irq+0x27/0x70 [ 31.000227] ____fput+0x15/0x20 [ 31.003482] task_work_run+0x199/0x270 [ 31.007345] ? task_work_cancel+0x210/0x210 [ 31.011643] ? _raw_spin_unlock+0x22/0x30 [ 31.015763] ? switch_task_namespaces+0x87/0xc0 [ 31.020409] do_exit+0xa52/0x1b40 [ 31.023835] ? lock_downgrade+0x990/0x990 [ 31.027953] ? __do_page_fault+0x35b/0xb60 [ 31.032175] ? mm_update_next_owner+0x930/0x930 [ 31.036820] ? __lock_is_held+0xbc/0x140 [ 31.040869] ? __fd_install+0x2f7/0x6a0 [ 31.044829] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 31.049561] ? get_unused_fd_flags+0x190/0x190 [ 31.054137] ? copy_user_generic_unrolled+0x89/0xc0 [ 31.059134] ? _copy_to_user+0xa2/0xc0 [ 31.062999] ? fd_install+0x4d/0x60 [ 31.066601] ? SYSC_accept4+0x4f2/0x850 [ 31.070559] ? kernel_accept+0x2f0/0x2f0 [ 31.074616] ? do_page_fault+0xee/0x720 [ 31.078565] ? sctp_transport_get_idx+0x70/0x70 [ 31.083204] ? __do_page_fault+0xb60/0xb60 [ 31.087413] ? selinux_socket_listen+0x36/0x40 [ 31.091965] ? security_socket_listen+0x81/0xb0 [ 31.096624] do_group_exit+0x149/0x400 [ 31.100484] ? lockdep_sys_exit+0x47/0xf0 [ 31.104622] ? SyS_exit+0x30/0x30 [ 31.108057] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 31.113046] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 31.117776] SyS_exit_group+0x1d/0x20 [ 31.121559] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 31.126297] RIP: 0033:0x43ea08 [ 31.129459] RSP: 002b:00007ffc1270fe58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 31.137142] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ea08 [ 31.144399] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 31.151641] RBP: 0000000000000082 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 31.158881] R10: 000000000000001c R11: 0000000000000246 R12: 0000000000401730 [ 31.166136] R13: 00000000004017c0 R14: 0000000000000000 R15: 0000000000000000 [ 31.173581] Dumping ftrace buffer: [ 31.177168] (ftrace buffer empty) [ 31.180850] Kernel Offset: disabled [ 31.184458] Rebooting in 86400 seconds..