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-1,10.128.0.39' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 41.982502] refcount_t: underflow; use-after-free. [ 41.983388] ------------[ cut here ]------------ [ 41.984144] WARNING: CPU: 1 PID: 3003 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 41.985353] Kernel panic - not syncing: panic_on_warn set ... [ 41.985353] [ 41.986375] CPU: 1 PID: 3003 Comm: syzkaller075749 Not tainted 4.13.0-rc5+ #42 [ 41.987341] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 41.988657] Call Trace: [ 41.989017] dump_stack+0x194/0x257 [ 41.989511] ? arch_local_irq_restore+0x53/0x53 [ 41.990160] panic+0x1e4/0x417 [ 41.990610] ? __warn+0x1d9/0x1d9 [ 41.991074] ? show_regs_print_info+0x65/0x65 [ 41.991688] ? refcount_sub_and_test+0x167/0x1b0 [ 41.992320] __warn+0x1c4/0x1d9 [ 41.992762] ? refcount_sub_and_test+0x167/0x1b0 [ 41.993396] report_bug+0x211/0x2d0 [ 41.993893] fixup_bug+0x40/0x90 [ 41.994348] do_trap+0x260/0x390 [ 41.994827] do_error_trap+0x120/0x390 [ 41.995356] ? do_trap+0x390/0x390 [ 41.995833] ? refcount_sub_and_test+0x167/0x1b0 [ 41.996500] ? vprintk_emit+0x3ea/0x590 [ 41.997059] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 41.997733] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 41.998394] do_invalid_op+0x1b/0x20 [ 41.998893] invalid_op+0x1e/0x30 [ 41.999361] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 42.000073] RSP: 0018:ffff8801d15f6810 EFLAGS: 00010282 [ 42.000797] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 42.001748] RDX: 0000000000000026 RSI: 1ffff1003a2becc2 RDI: ffffed003a2becf6 [ 42.003284] RBP: ffff8801d15f68a0 R08: 0000000000000001 R09: 0000000000000000 [ 42.010520] R10: ffff8801d15f7030 R11: 0000000000000000 R12: 1ffff1003a2bed03 [ 42.017763] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801d0ffaa3c [ 42.025035] ? refcount_inc+0x50/0x50 [ 42.028809] ? is_bpf_text_address+0x7b/0x120 [ 42.033278] sctp_wfree+0x183/0x620 [ 42.036873] ? __sctp_write_space+0x910/0x910 [ 42.041339] skb_release_head_state+0x124/0x200 [ 42.045978] skb_release_all+0x15/0x60 [ 42.049830] consume_skb+0x153/0x490 [ 42.053512] ? pskb_carve+0x1db0/0x1db0 [ 42.057453] ? is_bpf_text_address+0xa4/0x120 [ 42.061913] ? refcount_sub_and_test+0x115/0x1b0 [ 42.066639] ? refcount_inc+0x50/0x50 [ 42.070422] sctp_chunk_put+0x29c/0x420 [ 42.074364] ? save_trace+0x11f/0x350 [ 42.078134] ? sctp_chunk_hold+0x20/0x20 [ 42.082161] ? graph_lock+0x170/0x170 [ 42.085933] ? refcount_sub_and_test+0x115/0x1b0 [ 42.090666] ? refcount_sub_and_test+0x115/0x1b0 [ 42.095396] ? refcount_inc+0x50/0x50 [ 42.099170] ? __lock_acquire+0x2de2/0x3dc0 [ 42.103470] sctp_datamsg_put+0x22d/0x560 [ 42.107591] ? sctp_transport_dst_confirm+0x50/0x50 [ 42.112590] sctp_chunk_free+0x46/0x60 [ 42.116452] __sctp_outq_teardown+0xc7d/0x15a0 [ 42.121010] ? bpf_prog_kallsyms_find+0xbd/0x440 [ 42.125745] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 42.130639] ? is_bpf_text_address+0x7b/0x120 [ 42.135101] ? lock_downgrade+0x990/0x990 [ 42.139217] ? lock_release+0xa40/0xa40 [ 42.143163] ? update_stack_state+0x700/0x700 [ 42.147625] ? print_usage_bug+0x480/0x480 [ 42.151834] ? is_bpf_text_address+0xa4/0x120 [ 42.156295] ? unwind_get_return_address+0x61/0xa0 [ 42.161283] ? __save_stack_trace+0x7e/0xd0 [ 42.165578] ? check_noncircular+0x20/0x20 [ 42.169779] ? print_usage_bug+0x480/0x480 [ 42.173981] ? save_stack_trace+0x16/0x20 [ 42.178097] ? save_trace+0x11f/0x350 [ 42.181873] ? lock_acquire+0x1d5/0x580 [ 42.185812] ? lock_acquire+0x1d5/0x580 [ 42.189753] ? lock_timer_base+0x1a3/0x2b0 [ 42.193956] ? find_held_lock+0x35/0x1d0 [ 42.197993] ? sock_def_wakeup+0x1f9/0x350 [ 42.202193] ? lock_downgrade+0x990/0x990 [ 42.206308] ? lock_release+0xa40/0xa40 [ 42.210256] sctp_outq_free+0x15/0x20 [ 42.214049] sctp_association_free+0x2d0/0x930 [ 42.218609] ? sctp_asconf_queue_teardown+0x700/0x700 [ 42.223770] ? sock_def_wakeup+0x222/0x350 [ 42.227973] ? sk_dst_check+0x560/0x560 [ 42.231920] ? sctp_association_put+0x74/0x2f0 [ 42.236475] ? sctp_association_hold+0x20/0x20 [ 42.241032] ? __is_insn_slot_addr+0x1fc/0x330 [ 42.245586] ? sctp_sm_lookup_event+0x95/0x3c0 [ 42.250135] sctp_do_sm+0x28e7/0x6d90 [ 42.253905] ? check_noncircular+0x20/0x20 [ 42.258117] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 42.264146] ? print_usage_bug+0x480/0x480 [ 42.268351] ? print_usage_bug+0x480/0x480 [ 42.272566] ? find_held_lock+0x35/0x1d0 [ 42.276603] ? skb_dequeue+0x12a/0x180 [ 42.280458] ? lock_downgrade+0x990/0x990 [ 42.284579] ? do_raw_spin_trylock+0x190/0x190 [ 42.289133] ? mark_held_locks+0xaf/0x100 [ 42.293255] ? trace_hardirqs_on+0xd/0x10 [ 42.297382] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 42.301941] sctp_close+0x3c6/0x980 [ 42.305543] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 42.310785] ? unwind_get_return_address+0x61/0xa0 [ 42.315684] ? __save_stack_trace+0x7e/0xd0 [ 42.319981] ? check_noncircular+0x20/0x20 [ 42.324189] ? ipv6_sock_ac_close+0x2e8/0x3e0 [ 42.328655] ? ipv6_sock_mc_close+0x148/0x1a0 [ 42.333119] ? ipv6_sock_ac_drop+0x580/0x580 [ 42.337495] ? ip_mc_drop_socket+0x1ce/0x230 [ 42.341871] ? __fsnotify_parent+0xb4/0x3a0 [ 42.346165] inet_release+0xed/0x1c0 [ 42.349848] inet6_release+0x50/0x70 [ 42.353533] sock_release+0x8d/0x1e0 [ 42.357215] ? sock_release+0x1e0/0x1e0 [ 42.361164] sock_close+0x16/0x20 [ 42.364589] __fput+0x327/0x7e0 [ 42.367840] ? fput+0x140/0x140 [ 42.371087] ? do_raw_spin_trylock+0x190/0x190 [ 42.375647] ? check_same_owner+0x320/0x320 [ 42.379938] ____fput+0x15/0x20 [ 42.383184] task_work_run+0x18a/0x260 [ 42.387039] ? task_work_cancel+0x210/0x210 [ 42.391330] ? _raw_spin_unlock+0x22/0x30 [ 42.395460] ? switch_task_namespaces+0x87/0xc0 [ 42.400100] do_exit+0xa3a/0x1b10 [ 42.403531] ? __fd_install+0x2da/0x6a0 [ 42.407478] ? mm_update_next_owner+0x930/0x930 [ 42.412119] ? __lock_is_held+0xb6/0x140 [ 42.416158] ? __fd_install+0x2f7/0x6a0 [ 42.420097] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 42.424823] ? get_unused_fd_flags+0x190/0x190 [ 42.429378] ? retint_kernel+0x10/0x10 [ 42.433247] ? copy_user_generic_unrolled+0x89/0xc0 [ 42.438232] ? _copy_to_user+0xa2/0xc0 [ 42.442091] ? fd_install+0x4d/0x60 [ 42.445687] ? SYSC_accept4+0x4ec/0x850 [ 42.449632] ? kernel_accept+0x2f0/0x2f0 [ 42.453659] ? __do_page_fault+0x51b/0xb60 [ 42.457859] ? lock_downgrade+0x990/0x990 [ 42.461981] ? down_read_trylock+0xdb/0x170 [ 42.466272] ? __handle_mm_fault+0x3860/0x3860 [ 42.470820] ? vmacache_find+0x61/0x270 [ 42.474768] do_group_exit+0x149/0x400 [ 42.478625] ? SyS_exit+0x30/0x30 [ 42.482044] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 42.487028] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 42.491753] SyS_exit_group+0x1d/0x20 [ 42.495523] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 42.500243] RIP: 0033:0x43e9f8 [ 42.503397] RSP: 002b:00007ffdd0c83af8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 42.511071] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043e9f8 [ 42.518307] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 42.525546] RBP: 0000000000000086 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 42.532787] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401720 [ 42.540031] R13: 00000000004017b0 R14: 0000000000000000 R15: 0000000000000000 [ 42.547434] Dumping ftrace buffer: [ 42.550987] (ftrace buffer empty) [ 42.554665] Kernel Offset: disabled [ 42.558262] Rebooting in 86400 seconds..