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-2,10.128.0.45' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 53.460474] refcount_t: underflow; use-after-free. [ 53.465552] ------------[ cut here ]------------ [ 53.470410] WARNING: CPU: 0 PID: 2983 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 53.479097] Kernel panic - not syncing: panic_on_warn set ... [ 53.479097] [ 53.486430] CPU: 0 PID: 2983 Comm: syzkaller108783 Not tainted 4.13.0-mm1+ #7 [ 53.493671] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 53.503017] Call Trace: [ 53.505580] dump_stack+0x194/0x257 [ 53.509183] ? arch_local_irq_restore+0x53/0x53 [ 53.513836] panic+0x1e4/0x417 [ 53.516998] ? __warn+0x1d9/0x1d9 [ 53.520424] ? show_regs_print_info+0x65/0x65 [ 53.524905] ? refcount_sub_and_test+0x167/0x1b0 [ 53.529629] __warn+0x1c4/0x1d9 [ 53.532880] ? refcount_sub_and_test+0x167/0x1b0 [ 53.537611] report_bug+0x211/0x2d0 [ 53.541215] fixup_bug+0x40/0x90 [ 53.544553] do_trap+0x260/0x390 [ 53.547899] do_error_trap+0x120/0x390 [ 53.551763] ? do_trap+0x390/0x390 [ 53.555284] ? refcount_sub_and_test+0x167/0x1b0 [ 53.560007] ? vprintk_emit+0x3ea/0x590 [ 53.563961] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 53.568779] do_invalid_op+0x1b/0x20 [ 53.572464] invalid_op+0x18/0x20 [ 53.575887] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 53.581222] RSP: 0018:ffff8801ce616920 EFLAGS: 00010286 [ 53.586559] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 53.593805] RDX: 0000000000000026 RSI: 1ffff10039cc2ce4 RDI: ffffed0039cc2d18 [ 53.601047] RBP: ffff8801ce6169b0 R08: ffff8801ce616010 R09: 0000000000000000 [ 53.608286] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff10039cc2d25 [ 53.615526] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801d28c4ae4 [ 53.622798] ? refcount_inc+0x50/0x50 [ 53.626570] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 53.631295] ? sctp_association_free+0x2d0/0x930 [ 53.636038] ? sctp_do_sm+0x28e7/0x6dd0 [ 53.639980] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 53.644704] ? sctp_close+0x3c6/0x980 [ 53.648474] ? inet_release+0xed/0x1c0 [ 53.652337] sctp_wfree+0x183/0x620 [ 53.655935] ? __sctp_write_space+0x910/0x910 [ 53.660403] skb_release_head_state+0x124/0x200 [ 53.665044] skb_release_all+0x15/0x60 [ 53.668900] consume_skb+0x153/0x490 [ 53.672581] ? sctp_chunk_put+0x99/0x420 [ 53.676611] ? alloc_skb_with_frags+0x710/0x710 [ 53.681250] ? sctp_chunk_hold+0x20/0x20 [ 53.685284] ? refcount_sub_and_test+0x115/0x1b0 [ 53.690014] ? refcount_inc+0x50/0x50 [ 53.693786] ? mark_held_locks+0xb2/0x100 [ 53.697916] ? sctp_datamsg_put+0x456/0x560 [ 53.702217] sctp_chunk_put+0x29c/0x420 [ 53.706175] ? sctp_chunk_hold+0x20/0x20 [ 53.710215] ? sctp_transport_dst_confirm+0x50/0x50 [ 53.715222] sctp_chunk_free+0x53/0x60 [ 53.719083] __sctp_outq_teardown+0xc7d/0x15a0 [ 53.723635] ? inet6_release+0x50/0x70 [ 53.727501] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 53.732402] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 53.737391] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 53.742378] ? unwind_dump+0x4c0/0x4c0 [ 53.746237] ? unwind_dump+0x4c0/0x4c0 [ 53.750101] ? copy_trace+0x1d0/0x1d0 [ 53.753879] ? check_noncircular+0x20/0x20 [ 53.758084] ? check_noncircular+0x20/0x20 [ 53.762288] ? unwind_get_return_address+0x61/0xa0 [ 53.767197] ? __save_stack_trace+0x61/0xd0 [ 53.771489] ? check_noncircular+0x20/0x20 [ 53.775697] ? print_usage_bug+0x480/0x480 [ 53.779910] ? find_held_lock+0x39/0x1d0 [ 53.783953] ? lock_downgrade+0x990/0x990 [ 53.788080] ? sk_dst_check+0x560/0x560 [ 53.792030] ? rcu_read_lock_sched_held+0x108/0x120 [ 53.797022] ? lock_release+0xd70/0xd70 [ 53.800975] sctp_outq_free+0x15/0x20 [ 53.804789] sctp_association_free+0x2d0/0x930 [ 53.809347] ? sctp_asconf_queue_teardown+0x700/0x700 [ 53.814511] ? sock_def_wakeup+0x222/0x350 [ 53.818717] ? sk_dst_check+0x560/0x560 [ 53.822662] ? sctp_association_put+0x74/0x2f0 [ 53.827226] ? sctp_association_hold+0x20/0x20 [ 53.831782] ? unwind_dump+0x4c0/0x4c0 [ 53.835648] ? sctp_sm_lookup_event+0x95/0x3c0 [ 53.840214] sctp_do_sm+0x28e7/0x6dd0 [ 53.843999] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 53.850035] ? print_usage_bug+0x480/0x480 [ 53.854239] ? __lock_acquire+0x20fd/0x4620 [ 53.858552] ? print_usage_bug+0x480/0x480 [ 53.862760] ? find_held_lock+0x39/0x1d0 [ 53.866805] ? lock_downgrade+0x990/0x990 [ 53.870931] ? skb_dequeue+0x22/0x180 [ 53.874709] ? do_raw_spin_trylock+0x190/0x190 [ 53.879266] ? mark_held_locks+0xb2/0x100 [ 53.883393] ? trace_hardirqs_on+0xd/0x10 [ 53.887520] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 53.892077] sctp_close+0x3c6/0x980 [ 53.895684] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 53.900929] ? unwind_get_return_address+0x61/0xa0 [ 53.905832] ? check_noncircular+0x20/0x20 [ 53.910043] ? depot_save_stack+0x12c/0x490 [ 53.914343] ? ipv6_sock_ac_close+0x2e8/0x3e0 [ 53.918815] ? ipv6_sock_mc_close+0x148/0x1a0 [ 53.923280] ? ipv6_sock_ac_drop+0x580/0x580 [ 53.927659] ? ip_mc_drop_socket+0x1ce/0x230 [ 53.932036] ? __fsnotify_parent+0xb4/0x3a0 [ 53.936329] inet_release+0xed/0x1c0 [ 53.940017] inet6_release+0x50/0x70 [ 53.943712] sock_release+0x8d/0x1e0 [ 53.947397] ? sock_release+0x1e0/0x1e0 [ 53.951340] sock_close+0x16/0x20 [ 53.954765] __fput+0x333/0x7f0 [ 53.958033] ? fput+0x140/0x140 [ 53.961287] ? _raw_spin_unlock_irq+0x27/0x70 [ 53.965766] ____fput+0x15/0x20 [ 53.969021] task_work_run+0x199/0x270 [ 53.972883] ? task_work_cancel+0x210/0x210 [ 53.977179] ? _raw_spin_unlock+0x22/0x30 [ 53.981299] ? switch_task_namespaces+0x87/0xc0 [ 53.985945] do_exit+0xa52/0x1b40 [ 53.989369] ? lock_downgrade+0x990/0x990 [ 53.993492] ? __do_page_fault+0x35b/0xb60 [ 53.997714] ? mm_update_next_owner+0x930/0x930 [ 54.002359] ? __lock_is_held+0xbc/0x140 [ 54.006404] ? __fd_install+0x2f7/0x6a0 [ 54.010358] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 54.015088] ? get_unused_fd_flags+0x190/0x190 [ 54.019654] ? copy_user_generic_unrolled+0x89/0xc0 [ 54.024644] ? _copy_to_user+0xa2/0xc0 [ 54.028508] ? fd_install+0x4d/0x60 [ 54.032119] ? SYSC_accept4+0x4f2/0x850 [ 54.036070] ? kernel_accept+0x2f0/0x2f0 [ 54.040110] ? do_page_fault+0xee/0x720 [ 54.044056] ? sctp_transport_get_idx+0x70/0x70 [ 54.048697] ? __do_page_fault+0xb60/0xb60 [ 54.052906] ? selinux_socket_listen+0x36/0x40 [ 54.057470] ? security_socket_listen+0x81/0xb0 [ 54.062117] do_group_exit+0x149/0x400 [ 54.065977] ? lockdep_sys_exit+0x47/0xf0 [ 54.070096] ? SyS_exit+0x30/0x30 [ 54.073538] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 54.078527] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 54.083269] SyS_exit_group+0x1d/0x20 [ 54.087044] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 54.091768] RIP: 0033:0x43e9f8 [ 54.094932] RSP: 002b:00007ffcb0ce6988 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 54.102613] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043e9f8 [ 54.109855] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 54.117096] RBP: 0000000000000082 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 54.124338] R10: 000000000000001c R11: 0000000000000246 R12: 0000000000401720 [ 54.131580] R13: 00000000004017b0 R14: 0000000000000000 R15: 0000000000000000 [ 54.139770] Dumping ftrace buffer: [ 54.143349] (ftrace buffer empty) [ 54.147036] Kernel Offset: disabled [ 54.150645] Rebooting in 86400 seconds..