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-386-0,10.128.0.43' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 35.305810] refcount_t: underflow; use-after-free. [ 35.310878] ------------[ cut here ]------------ [ 35.315731] WARNING: CPU: 1 PID: 2990 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 35.324391] Kernel panic - not syncing: panic_on_warn set ... [ 35.324391] [ 35.331725] CPU: 1 PID: 2990 Comm: syzkaller475673 Not tainted 4.14.0-rc2+ #10 [ 35.339053] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 35.348388] Call Trace: [ 35.350947] dump_stack+0x194/0x257 [ 35.354549] ? arch_local_irq_restore+0x53/0x53 [ 35.359203] panic+0x1e4/0x417 [ 35.362367] ? __warn+0x1d9/0x1d9 [ 35.365791] ? show_regs_print_info+0x65/0x65 [ 35.370272] ? refcount_sub_and_test+0x167/0x1b0 [ 35.374996] __warn+0x1c4/0x1d9 [ 35.378247] ? refcount_sub_and_test+0x167/0x1b0 [ 35.382976] report_bug+0x211/0x2d0 [ 35.386580] fixup_bug+0x40/0x90 [ 35.389917] do_trap+0x260/0x390 [ 35.393269] do_error_trap+0x120/0x390 [ 35.397129] ? do_trap+0x390/0x390 [ 35.400641] ? refcount_sub_and_test+0x167/0x1b0 [ 35.406235] ? vprintk_emit+0x3ea/0x590 [ 35.410190] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 35.415009] do_invalid_op+0x1b/0x20 [ 35.418693] invalid_op+0x18/0x20 [ 35.422116] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 35.427444] RSP: 0018:ffff8801ce6fe7e0 EFLAGS: 00010282 [ 35.432780] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 35.440021] RDX: 0000000000000026 RSI: 1ffff10039cdfcbc RDI: ffffed0039cdfcf0 [ 35.447261] RBP: ffff8801ce6fe870 R08: ffff8801ce6fded0 R09: 0000000000000000 [ 35.454499] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff10039cdfcfd [ 35.461739] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801d28f2ae4 [ 35.469002] ? refcount_inc+0x50/0x50 [ 35.472774] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 35.477499] ? sctp_association_free+0x2d0/0x930 [ 35.482225] ? sctp_do_sm+0x28e7/0x6dd0 [ 35.486175] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 35.490898] ? sctp_close+0x3c6/0x980 [ 35.494668] ? inet_release+0xed/0x1c0 [ 35.498532] sctp_wfree+0x183/0x620 [ 35.502130] ? __sctp_write_space+0x910/0x910 [ 35.506600] skb_release_head_state+0x124/0x200 [ 35.511240] skb_release_all+0x15/0x60 [ 35.515096] consume_skb+0x153/0x490 [ 35.518779] ? sctp_chunk_put+0x99/0x420 [ 35.522810] ? alloc_skb_with_frags+0x710/0x710 [ 35.527447] ? sctp_chunk_hold+0x20/0x20 [ 35.531480] ? refcount_sub_and_test+0x115/0x1b0 [ 35.536206] ? refcount_inc+0x50/0x50 [ 35.539977] ? mark_held_locks+0xb2/0x100 [ 35.544097] ? sctp_datamsg_put+0x456/0x560 [ 35.548395] sctp_chunk_put+0x29c/0x420 [ 35.552343] ? sctp_chunk_hold+0x20/0x20 [ 35.556378] ? sctp_transport_dst_confirm+0x50/0x50 [ 35.561382] sctp_chunk_free+0x53/0x60 [ 35.565239] __sctp_outq_teardown+0xc7d/0x15a0 [ 35.569885] ? inet6_release+0x50/0x70 [ 35.573749] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 35.578651] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 35.583642] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 35.588626] ? unwind_dump+0x4c0/0x4c0 [ 35.592485] ? unwind_dump+0x4c0/0x4c0 [ 35.596346] ? copy_trace+0x1d0/0x1d0 [ 35.600124] ? check_noncircular+0x20/0x20 [ 35.604328] ? check_noncircular+0x20/0x20 [ 35.608530] ? unwind_get_return_address+0x61/0xa0 [ 35.613433] ? __save_stack_trace+0x61/0xd0 [ 35.617726] ? check_noncircular+0x20/0x20 [ 35.621934] ? print_usage_bug+0x480/0x480 [ 35.626146] ? find_held_lock+0x39/0x1d0 [ 35.630188] ? lock_downgrade+0x990/0x990 [ 35.634318] ? sk_dst_check+0x560/0x560 [ 35.638268] ? rcu_read_lock_sched_held+0x108/0x120 [ 35.643268] ? lock_release+0xd70/0xd70 [ 35.647223] sctp_outq_free+0x15/0x20 [ 35.651008] sctp_association_free+0x2d0/0x930 [ 35.655565] ? sctp_asconf_queue_teardown+0x700/0x700 [ 35.660724] ? sock_def_wakeup+0x222/0x350 [ 35.664940] ? sk_dst_check+0x560/0x560 [ 35.668895] ? sctp_association_put+0x74/0x2f0 [ 35.673447] ? sctp_association_hold+0x20/0x20 [ 35.678001] ? unwind_dump+0x4c0/0x4c0 [ 35.681866] sctp_do_sm+0x28e7/0x6dd0 [ 35.685652] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 35.691685] ? print_usage_bug+0x480/0x480 [ 35.695888] ? __lock_acquire+0x20fd/0x4620 [ 35.700186] ? print_usage_bug+0x480/0x480 [ 35.704393] ? find_held_lock+0x39/0x1d0 [ 35.708434] ? lock_downgrade+0x990/0x990 [ 35.712559] ? skb_dequeue+0x22/0x180 [ 35.716337] ? do_raw_spin_trylock+0x190/0x190 [ 35.720893] ? mark_held_locks+0xb2/0x100 [ 35.725021] ? trace_hardirqs_on+0xd/0x10 [ 35.729146] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 35.733704] sctp_close+0x3c6/0x980 [ 35.737313] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 35.742567] ? unwind_get_return_address+0x61/0xa0 [ 35.747468] ? check_noncircular+0x20/0x20 [ 35.751677] ? depot_save_stack+0x3b5/0x490 [ 35.755976] ? ipv6_sock_ac_close+0x2e8/0x3e0 [ 35.760445] ? ipv6_sock_mc_close+0x148/0x1a0 [ 35.764916] ? ip_mc_drop_socket+0x1ce/0x230 [ 35.769297] ? __fsnotify_parent+0xb4/0x3a0 [ 35.773598] inet_release+0xed/0x1c0 [ 35.777295] inet6_release+0x50/0x70 [ 35.780986] sock_release+0x8d/0x1e0 [ 35.784675] ? sock_release+0x1e0/0x1e0 [ 35.788623] sock_close+0x16/0x20 [ 35.792051] __fput+0x333/0x7f0 [ 35.795312] ? fput+0x140/0x140 [ 35.798572] ? _raw_spin_unlock_irq+0x27/0x70 [ 35.803047] ____fput+0x15/0x20 [ 35.806303] task_work_run+0x199/0x270 [ 35.810167] ? task_work_cancel+0x210/0x210 [ 35.814462] ? _raw_spin_unlock+0x22/0x30 [ 35.818581] ? switch_task_namespaces+0x87/0xc0 [ 35.823225] do_exit+0x9d2/0x1af0 [ 35.826649] ? get_unused_fd_flags+0x190/0x190 [ 35.831209] ? mm_update_next_owner+0x930/0x930 [ 35.835853] ? __lock_is_held+0xbc/0x140 [ 35.839901] ? __fd_install+0x2f7/0x6a0 [ 35.843851] ? get_unused_fd_flags+0x190/0x190 [ 35.848414] ? __might_sleep+0x95/0x190 [ 35.852369] ? kasan_check_read+0x11/0x20 [ 35.856488] ? _copy_to_user+0xa2/0xc0 [ 35.860352] ? fd_install+0x4d/0x60 [ 35.863951] ? SYSC_accept4+0x4f2/0x850 [ 35.867902] ? kernel_accept+0x2f0/0x2f0 [ 35.871958] do_group_exit+0x149/0x400 [ 35.875814] ? __handle_mm_fault+0x39c0/0x39c0 [ 35.880365] ? vmacache_find+0x5f/0x280 [ 35.884311] ? SyS_exit+0x30/0x30 [ 35.887742] ? do_fast_syscall_32+0x158/0xf05 [ 35.892208] ? do_group_exit+0x400/0x400 [ 35.896239] SyS_exit_group+0x1d/0x20 [ 35.900012] do_fast_syscall_32+0x3f2/0xf05 [ 35.904312] ? do_int80_syscall_32+0x940/0x940 [ 35.908869] ? kasan_check_read+0x11/0x20 [ 35.912990] ? syscall_return_slowpath+0x510/0x510 [ 35.917892] ? SyS_rt_sigaction+0x94/0x1b0 [ 35.922106] ? sysret32_from_system_call+0x5/0x3b [ 35.926924] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 35.931749] entry_SYSENTER_compat+0x51/0x60 [ 35.936131] RIP: 0023:0xf7f6fc79 [ 35.939467] RSP: 002b:00000000ff8b4bbc EFLAGS: 00000296 ORIG_RAX: 00000000000000fc [ 35.947168] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000080eb298 [ 35.954412] RDX: 0000000000000000 RSI: 00000000080d5858 RDI: 00000000080eb2a0 [ 35.961653] RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 [ 35.968896] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 35.976156] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 35.983929] Dumping ftrace buffer: [ 35.987474] (ftrace buffer empty) [ 35.991156] Kernel Offset: disabled [ 35.994759] Rebooting in 86400 seconds..