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-1,10.128.0.61' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 41.646547] refcount_t: underflow; use-after-free. [ 41.647472] ------------[ cut here ]------------ [ 41.648299] WARNING: CPU: 0 PID: 2985 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 41.649484] Kernel panic - not syncing: panic_on_warn set ... [ 41.649484] [ 41.650459] CPU: 0 PID: 2985 Comm: syzkaller989314 Not tainted 4.13.0-mm1+ #7 [ 41.651416] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 41.652670] Call Trace: [ 41.653036] dump_stack+0x194/0x257 [ 41.653532] ? arch_local_irq_restore+0x53/0x53 [ 41.654171] panic+0x1e4/0x417 [ 41.654612] ? __warn+0x1d9/0x1d9 [ 41.655115] ? show_regs_print_info+0x65/0x65 [ 41.655771] ? refcount_sub_and_test+0x167/0x1b0 [ 41.656408] __warn+0x1c4/0x1d9 [ 41.656858] ? refcount_sub_and_test+0x167/0x1b0 [ 41.657499] report_bug+0x211/0x2d0 [ 41.658011] fixup_bug+0x40/0x90 [ 41.658497] do_trap+0x260/0x390 [ 41.658982] do_error_trap+0x120/0x390 [ 41.659507] ? vprintk_emit+0x49b/0x590 [ 41.660049] ? do_trap+0x390/0x390 [ 41.660606] ? refcount_sub_and_test+0x167/0x1b0 [ 41.661261] ? vprintk_emit+0x3ea/0x590 [ 41.661805] ? lock_release+0xd70/0xd70 [ 41.662348] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 41.663001] do_invalid_op+0x1b/0x20 [ 41.663508] invalid_op+0x18/0x20 [ 41.663977] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 41.664689] RSP: 0018:ffff8801cebbe808 EFLAGS: 00010286 [ 41.665434] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 41.666471] RDX: 0000000000000026 RSI: 1ffff10039d77cc1 RDI: ffffed0039d77cf5 [ 41.672375] RBP: ffff8801cebbe898 R08: ffff8801cebbdef8 R09: 0000000000000000 [ 41.679623] R10: ffff8801ce9dc180 R11: 0000000000000000 R12: 1ffff10039d77d02 [ 41.686869] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801d2862ae4 [ 41.694139] ? refcount_sub_and_test+0x167/0x1b0 [ 41.698871] ? refcount_inc+0x50/0x50 [ 41.702645] ? add_lock_to_list.isra.33+0x1ff/0x4f0 [ 41.707646] sctp_wfree+0x183/0x620 [ 41.711244] ? __sctp_write_space+0x910/0x910 [ 41.715717] skb_release_head_state+0x124/0x200 [ 41.720358] skb_release_all+0x15/0x60 [ 41.724218] consume_skb+0x153/0x490 [ 41.727905] ? alloc_skb_with_frags+0x710/0x710 [ 41.732549] ? __unwind_start+0x169/0x330 [ 41.736667] ? refcount_sub_and_test+0x115/0x1b0 [ 41.741394] ? refcount_inc+0x50/0x50 [ 41.745163] ? unwind_get_return_address+0x61/0xa0 [ 41.750082] sctp_chunk_put+0x29c/0x420 [ 41.754038] ? sctp_chunk_hold+0x20/0x20 [ 41.758076] ? refcount_sub_and_test+0x115/0x1b0 [ 41.762812] ? refcount_sub_and_test+0x115/0x1b0 [ 41.767539] ? refcount_inc+0x50/0x50 [ 41.771318] ? __lock_acquire+0x732/0x4620 [ 41.775532] sctp_datamsg_put+0x22d/0x560 [ 41.779659] ? sctp_transport_dst_confirm+0x50/0x50 [ 41.784666] sctp_chunk_free+0x46/0x60 [ 41.788529] __sctp_outq_teardown+0xc7d/0x15a0 [ 41.793085] ? inet6_release+0x50/0x70 [ 41.796960] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 41.801868] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 41.806859] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 41.811849] ? unwind_dump+0x4c0/0x4c0 [ 41.815723] ? unwind_dump+0x4c0/0x4c0 [ 41.819588] ? copy_trace+0x1d0/0x1d0 [ 41.823377] ? check_noncircular+0x20/0x20 [ 41.827586] ? check_noncircular+0x20/0x20 [ 41.831792] ? unwind_get_return_address+0x61/0xa0 [ 41.836709] ? __save_stack_trace+0x61/0xd0 [ 41.841016] ? check_noncircular+0x20/0x20 [ 41.845233] ? print_usage_bug+0x480/0x480 [ 41.849445] ? find_held_lock+0x39/0x1d0 [ 41.853486] ? lock_downgrade+0x990/0x990 [ 41.857614] ? sk_dst_check+0x560/0x560 [ 41.861562] ? rcu_read_lock_sched_held+0x108/0x120 [ 41.866552] ? lock_release+0xd70/0xd70 [ 41.870509] sctp_outq_free+0x15/0x20 [ 41.874282] sctp_association_free+0x2d0/0x930 [ 41.878854] ? sctp_asconf_queue_teardown+0x700/0x700 [ 41.884024] ? sock_def_wakeup+0x222/0x350 [ 41.888232] ? sk_dst_check+0x560/0x560 [ 41.892181] ? sctp_association_put+0x74/0x2f0 [ 41.896734] ? sctp_association_hold+0x20/0x20 [ 41.901289] ? unwind_dump+0x4c0/0x4c0 [ 41.905153] ? sctp_sm_lookup_event+0x95/0x3c0 [ 41.909709] sctp_do_sm+0x28e7/0x6dd0 [ 41.913494] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 41.919530] ? print_usage_bug+0x480/0x480 [ 41.923734] ? __lock_acquire+0x20fd/0x4620 [ 41.928034] ? print_usage_bug+0x480/0x480 [ 41.932245] ? find_held_lock+0x39/0x1d0 [ 41.936295] ? lock_downgrade+0x990/0x990 [ 41.940429] ? skb_dequeue+0x22/0x180 [ 41.944216] ? do_raw_spin_trylock+0x190/0x190 [ 41.948789] ? mark_held_locks+0xb2/0x100 [ 41.952946] ? trace_hardirqs_on+0xd/0x10 [ 41.957081] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 41.961643] sctp_close+0x3c6/0x980 [ 41.965256] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 41.970510] ? unwind_get_return_address+0x61/0xa0 [ 41.975437] ? check_noncircular+0x20/0x20 [ 41.979668] ? depot_save_stack+0x12c/0x490 [ 41.983991] ? ipv6_sock_ac_close+0x2e8/0x3e0 [ 41.988478] ? ipv6_sock_mc_close+0x148/0x1a0 [ 41.992963] ? ipv6_sock_ac_drop+0x580/0x580 [ 41.997368] ? ip_mc_drop_socket+0x1ce/0x230 [ 42.001762] ? __fsnotify_parent+0xb4/0x3a0 [ 42.006076] inet_release+0xed/0x1c0 [ 42.009784] inet6_release+0x50/0x70 [ 42.013493] sock_release+0x8d/0x1e0 [ 42.017214] ? sock_release+0x1e0/0x1e0 [ 42.021169] sock_close+0x16/0x20 [ 42.024604] __fput+0x333/0x7f0 [ 42.027861] ? fput+0x140/0x140 [ 42.031116] ? _raw_spin_unlock_irq+0x27/0x70 [ 42.035589] ____fput+0x15/0x20 [ 42.038844] task_work_run+0x199/0x270 [ 42.042708] ? task_work_cancel+0x210/0x210 [ 42.047002] ? _raw_spin_unlock+0x22/0x30 [ 42.051122] ? switch_task_namespaces+0x87/0xc0 [ 42.055769] do_exit+0xa52/0x1b40 [ 42.059194] ? __do_page_fault+0x35b/0xb60 [ 42.063406] ? get_unused_fd_flags+0x190/0x190 [ 42.067969] ? mm_update_next_owner+0x930/0x930 [ 42.072614] ? __lock_is_held+0xbc/0x140 [ 42.076660] ? __fd_install+0x2f7/0x6a0 [ 42.080605] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 42.085337] ? get_unused_fd_flags+0x190/0x190 [ 42.089895] ? retint_kernel+0x10/0x10 [ 42.093770] ? copy_user_generic_unrolled+0x89/0xc0 [ 42.098763] ? _copy_to_user+0xa2/0xc0 [ 42.102627] ? fd_install+0x4d/0x60 [ 42.106230] ? SYSC_accept4+0x4f2/0x850 [ 42.110186] ? kernel_accept+0x2f0/0x2f0 [ 42.114229] ? do_page_fault+0xee/0x720 [ 42.118180] ? sctp_transport_get_idx+0x70/0x70 [ 42.122828] ? selinux_socket_listen+0x36/0x40 [ 42.127382] ? security_socket_listen+0x81/0xb0 [ 42.132031] do_group_exit+0x149/0x400 [ 42.135901] ? lockdep_sys_exit+0x47/0xf0 [ 42.140024] ? SyS_exit+0x30/0x30 [ 42.143450] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 42.148441] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 42.153176] SyS_exit_group+0x1d/0x20 [ 42.156950] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 42.161680] RIP: 0033:0x43e9f8 [ 42.164842] RSP: 002b:00007ffc63e30e18 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 42.172525] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043e9f8 [ 42.179766] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 42.187017] RBP: 0000000000000082 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 42.194261] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401720 [ 42.201503] R13: 00000000004017b0 R14: 0000000000000000 R15: 0000000000000000 [ 42.208953] Dumping ftrace buffer: [ 42.212523] (ftrace buffer empty) [ 42.216210] Kernel Offset: disabled [ 42.219818] Rebooting in 86400 seconds..