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-next-kasan-gce-3,10.128.0.43' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 45.807495] refcount_t: underflow; use-after-free. [ 45.808438] ------------[ cut here ]------------ [ 45.809276] WARNING: CPU: 1 PID: 3030 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 45.810464] Kernel panic - not syncing: panic_on_warn set ... [ 45.810464] [ 45.811490] CPU: 1 PID: 3030 Comm: syzkaller433278 Not tainted 4.13.0-rc5-next-20170815+ #3 [ 45.812676] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.813983] Call Trace: [ 45.814401] dump_stack+0x194/0x257 [ 45.814894] ? arch_local_irq_restore+0x53/0x53 [ 45.815528] panic+0x1e4/0x417 [ 45.816009] ? __warn+0x1d9/0x1d9 [ 45.816472] ? show_regs_print_info+0x65/0x65 [ 45.817084] ? refcount_sub_and_test+0x167/0x1b0 [ 45.817735] __warn+0x1c4/0x1d9 [ 45.818178] ? refcount_sub_and_test+0x167/0x1b0 [ 45.818815] report_bug+0x211/0x2d0 [ 45.819320] fixup_bug+0x40/0x90 [ 45.819774] do_trap+0x260/0x390 [ 45.820236] do_error_trap+0x120/0x390 [ 45.820762] ? do_trap+0x390/0x390 [ 45.821257] ? refcount_sub_and_test+0x167/0x1b0 [ 45.821889] ? vprintk_emit+0x3ea/0x590 [ 45.822433] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 45.823141] do_invalid_op+0x1b/0x20 [ 45.823667] invalid_op+0x1e/0x30 [ 45.824167] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 45.824874] RSP: 0018:ffff8801d0c9e920 EFLAGS: 00010286 [ 45.825596] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 45.826548] RDX: 0000000000000026 RSI: 1ffff1003a193ce4 RDI: ffffed003a193d18 [ 45.827527] RBP: ffff8801d0c9e9b0 R08: 0000000000000001 R09: 0000000000000000 [ 45.834042] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1003a193d25 [ 45.841279] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801cf7d3a3c [ 45.848711] ? refcount_inc+0x50/0x50 [ 45.852563] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 45.857382] ? sctp_association_free+0x2d0/0x930 [ 45.862116] ? sctp_do_sm+0x28e7/0x6d90 [ 45.866056] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 45.870786] ? sctp_close+0x3c6/0x980 [ 45.874726] ? inet_release+0xed/0x1c0 [ 45.878584] sctp_wfree+0x183/0x620 [ 45.882178] ? __sctp_write_space+0x910/0x910 [ 45.886644] skb_release_head_state+0x124/0x200 [ 45.891282] skb_release_all+0x15/0x60 [ 45.895135] consume_skb+0x153/0x490 [ 45.898818] ? sctp_chunk_put+0x99/0x420 [ 45.902846] ? alloc_skb_with_frags+0x710/0x710 [ 45.907482] ? sctp_chunk_hold+0x20/0x20 [ 45.911514] ? refcount_sub_and_test+0x115/0x1b0 [ 45.916245] ? refcount_inc+0x50/0x50 [ 45.920014] ? mark_held_locks+0xaf/0x100 [ 45.924141] ? sctp_datamsg_put+0x456/0x560 [ 45.928445] sctp_chunk_put+0x29c/0x420 [ 45.932391] ? sctp_chunk_hold+0x20/0x20 [ 45.936424] ? sctp_transport_dst_confirm+0x50/0x50 [ 45.941409] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 45.946565] ? lock_release+0xa40/0xa40 [ 45.950508] ? __read_once_size_nocheck.constprop.8+0x10/0x10 [ 45.956363] ? entry_SYSCALL_64_fastpath+0x1f/0xbe [ 45.961258] ? bpf_prog_kallsyms_find+0xbd/0x440 [ 45.965986] ? show_initstate+0xb0/0xb0 [ 45.969933] sctp_chunk_free+0x53/0x60 [ 45.973792] __sctp_outq_teardown+0xc7d/0x15a0 [ 45.978342] ? lock_downgrade+0x990/0x990 [ 45.982465] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 45.987370] ? unwind_dump+0x4c0/0x4c0 [ 45.991238] ? is_bpf_text_address+0xa4/0x120 [ 45.995702] ? __kernel_text_address+0xae/0xe0 [ 46.000256] ? unwind_get_return_address+0x61/0xa0 [ 46.005153] ? __save_stack_trace+0x7e/0xd0 [ 46.009450] ? add_lock_to_list.isra.35+0x1ff/0x4f0 [ 46.014439] ? SOFTIRQ_verbose+0x10/0x10 [ 46.018465] ? save_stack_trace+0x16/0x20 [ 46.022582] ? check_noncircular+0x20/0x20 [ 46.026782] ? print_usage_bug+0x480/0x480 [ 46.030993] ? lock_acquire+0x1d5/0x580 [ 46.034930] ? lock_acquire+0x1d5/0x580 [ 46.038869] ? lock_timer_base+0x1a3/0x2b0 [ 46.043074] ? find_held_lock+0x35/0x1d0 [ 46.047109] ? sock_def_wakeup+0x1f9/0x350 [ 46.051317] ? lock_downgrade+0x990/0x990 [ 46.055436] ? lock_release+0xa40/0xa40 [ 46.059383] sctp_outq_free+0x15/0x20 [ 46.063151] sctp_association_free+0x2d0/0x930 [ 46.067705] ? sctp_asconf_queue_teardown+0x700/0x700 [ 46.072864] ? sock_def_wakeup+0x222/0x350 [ 46.077718] ? sk_dst_check+0x560/0x560 [ 46.081665] ? sctp_association_put+0x74/0x2f0 [ 46.086215] ? sctp_association_hold+0x20/0x20 [ 46.090768] ? sctp_sm_lookup_event+0x95/0x3c0 [ 46.095320] sctp_do_sm+0x28e7/0x6d90 [ 46.099534] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 46.105564] ? print_usage_bug+0x480/0x480 [ 46.109764] ? __lock_acquire+0x6aa/0x3bc0 [ 46.113970] ? print_usage_bug+0x480/0x480 [ 46.118177] ? __lock_acquire+0x6aa/0x3bc0 [ 46.122386] ? find_held_lock+0x35/0x1d0 [ 46.126420] ? skb_dequeue+0x12a/0x180 [ 46.130274] ? lock_downgrade+0x990/0x990 [ 46.134392] ? do_raw_spin_trylock+0x190/0x190 [ 46.138944] ? mark_held_locks+0xaf/0x100 [ 46.143074] ? trace_hardirqs_on+0xd/0x10 [ 46.147196] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 46.151749] sctp_close+0x3c6/0x980 [ 46.155350] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 46.160592] ? unwind_get_return_address+0x61/0xa0 [ 46.165488] ? __save_stack_trace+0x7e/0xd0 [ 46.169781] ? check_noncircular+0x20/0x20 [ 46.173985] ? check_noncircular+0x20/0x20 [ 46.178196] ? ipv6_sock_ac_close+0x2e8/0x3e0 [ 46.182660] ? ipv6_sock_mc_close+0x148/0x1a0 [ 46.187120] ? ipv6_sock_ac_drop+0x580/0x580 [ 46.191493] ? ip_mc_drop_socket+0x1ce/0x230 [ 46.195867] ? __fsnotify_parent+0xb4/0x3a0 [ 46.200164] inet_release+0xed/0x1c0 [ 46.203847] inet6_release+0x50/0x70 [ 46.207529] sock_release+0x8d/0x1e0 [ 46.211211] ? sock_release+0x1e0/0x1e0 [ 46.215151] sock_close+0x16/0x20 [ 46.218572] __fput+0x327/0x7e0 [ 46.221824] ? fput+0x140/0x140 [ 46.225073] ? _raw_spin_unlock_irq+0x27/0x70 [ 46.229540] ____fput+0x15/0x20 [ 46.232788] task_work_run+0x199/0x270 [ 46.236653] ? task_work_cancel+0x210/0x210 [ 46.240942] ? _raw_spin_unlock+0x22/0x30 [ 46.245065] ? switch_task_namespaces+0x87/0xc0 [ 46.249711] do_exit+0xa52/0x1b30 [ 46.253128] ? find_held_lock+0x35/0x1d0 [ 46.257165] ? lock_downgrade+0x990/0x990 [ 46.261281] ? mm_update_next_owner+0x930/0x930 [ 46.265920] ? __lock_is_held+0xb6/0x140 [ 46.269963] ? __fd_install+0x2f7/0x6a0 [ 46.273902] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 46.278628] ? get_unused_fd_flags+0x190/0x190 [ 46.283190] ? copy_user_generic_unrolled+0x89/0xc0 [ 46.288174] ? _copy_to_user+0xa2/0xc0 [ 46.292032] ? fd_install+0x4d/0x60 [ 46.295626] ? SYSC_accept4+0x4ec/0x850 [ 46.299573] ? kernel_accept+0x2f0/0x2f0 [ 46.303611] ? lock_downgrade+0x990/0x990 [ 46.307738] ? handle_mm_fault+0x4e3/0x940 [ 46.311944] ? __handle_mm_fault+0x3980/0x3980 [ 46.316494] ? vmacache_find+0x61/0x270 [ 46.320439] do_group_exit+0x149/0x400 [ 46.324294] ? SyS_exit+0x30/0x30 [ 46.327714] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 46.333828] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 46.338814] SyS_exit_group+0x1d/0x20 [ 46.342583] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 46.347305] RIP: 0033:0x43e9f8 [ 46.350462] RSP: 002b:00007ffee58562e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 46.358147] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043e9f8 [ 46.365382] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 46.372627] RBP: 0000000000000086 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 46.379956] R10: 000000000000001c R11: 0000000000000246 R12: 0000000000401720 [ 46.387200] R13: 00000000004017b0 R14: 0000000000000000 R15: 0000000000000000 [ 46.394600] Dumping ftrace buffer: [ 46.398178] (ftrace buffer empty) [ 46.401857] Kernel Offset: disabled [ 46.405455] Rebooting in 86400 seconds..