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-2,10.128.0.48' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 63.387259] refcount_t: underflow; use-after-free. [ 63.388158] ------------[ cut here ]------------ [ 63.388800] WARNING: CPU: 0 PID: 2994 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 63.390044] Kernel panic - not syncing: panic_on_warn set ... [ 63.390044] [ 63.391014] CPU: 0 PID: 2994 Comm: syzkaller528564 Not tainted 4.14.0-rc6+ #146 [ 63.392028] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 63.393302] Call Trace: [ 63.393661] dump_stack+0x194/0x257 [ 63.394152] ? arch_local_irq_restore+0x53/0x53 [ 63.394786] panic+0x1e4/0x417 [ 63.395239] ? __warn+0x1d9/0x1d9 [ 63.395704] ? show_regs_print_info+0x65/0x65 [ 63.396315] ? refcount_sub_and_test+0x167/0x1b0 [ 63.396948] __warn+0x1c4/0x1d9 [ 63.397390] ? refcount_sub_and_test+0x167/0x1b0 [ 63.398024] report_bug+0x211/0x2d0 [ 63.398520] fixup_bug+0x40/0x90 [ 63.398976] do_trap+0x260/0x390 [ 63.399454] do_error_trap+0x120/0x390 [ 63.399974] ? vprintk_emit+0x49b/0x590 [ 63.400511] ? do_trap+0x390/0x390 [ 63.400992] ? refcount_sub_and_test+0x167/0x1b0 [ 63.401622] ? vprintk_emit+0x3ea/0x590 [ 63.402163] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 63.402855] do_invalid_op+0x1b/0x20 [ 63.403354] invalid_op+0x18/0x20 [ 63.403863] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 63.404581] RSP: 0018:ffff8801d1c96908 EFLAGS: 00010286 [ 63.405290] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 63.406241] RDX: 0000000000000026 RSI: 1ffff1003a392ce1 RDI: ffffed003a392d15 [ 63.407209] RBP: ffff8801d1c96998 R08: 0000000000000001 R09: 0000000000000000 [ 63.413177] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1003a392d22 [ 63.420414] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801d2244a3c [ 63.427668] ? refcount_sub_and_test+0x167/0x1b0 [ 63.432391] ? refcount_inc+0x50/0x50 [ 63.436159] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 63.440879] ? sctp_association_free+0x2d0/0x930 [ 63.445600] ? sctp_do_sm+0x28e7/0x6dd0 [ 63.449538] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 63.454257] ? sctp_close+0x3c6/0x980 [ 63.458023] ? inet_release+0xed/0x1c0 [ 63.461882] sctp_wfree+0x183/0x620 [ 63.465478] ? __sctp_write_space+0x910/0x910 [ 63.469952] skb_release_head_state+0x124/0x200 [ 63.474588] skb_release_all+0x15/0x60 [ 63.478443] consume_skb+0x153/0x490 [ 63.482121] ? sctp_chunk_put+0x99/0x420 [ 63.486160] ? alloc_skb_with_frags+0x710/0x710 [ 63.490793] ? sctp_chunk_hold+0x20/0x20 [ 63.494824] ? refcount_sub_and_test+0x115/0x1b0 [ 63.499546] ? refcount_inc+0x50/0x50 [ 63.503316] ? mark_held_locks+0xaf/0x100 [ 63.507432] ? sctp_datamsg_put+0x456/0x560 [ 63.511727] sctp_chunk_put+0x29c/0x420 [ 63.515670] ? sctp_chunk_hold+0x20/0x20 [ 63.519701] ? sctp_transport_dst_confirm+0x50/0x50 [ 63.524683] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 63.529840] ? lock_release+0xa40/0xa40 [ 63.533781] ? trace_hardirqs_off+0xd/0x10 [ 63.537985] ? _raw_spin_unlock_irqrestore+0xa6/0xba [ 63.543057] sctp_chunk_free+0x53/0x60 [ 63.546912] __sctp_outq_teardown+0xc7d/0x15a0 [ 63.551467] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 63.556370] ? rcutorture_record_progress+0x10/0x10 [ 63.561388] ? is_bpf_text_address+0xa4/0x120 [ 63.565853] ? kernel_text_address+0x102/0x140 [ 63.570403] ? __kernel_text_address+0xd/0x40 [ 63.574865] ? unwind_get_return_address+0x61/0xa0 [ 63.579762] ? __save_stack_trace+0x7e/0xd0 [ 63.584068] ? print_irqtrace_events+0x270/0x270 [ 63.588797] ? check_noncircular+0x20/0x20 [ 63.593005] ? default_wake_function+0x30/0x50 [ 63.597552] ? autoremove_wake_function+0x78/0x350 [ 63.602454] ? find_held_lock+0x35/0x1d0 [ 63.606489] ? find_held_lock+0x35/0x1d0 [ 63.610523] ? sock_def_wakeup+0x1f9/0x350 [ 63.614725] ? lock_downgrade+0x990/0x990 [ 63.618841] ? lock_release+0xa40/0xa40 [ 63.622786] sctp_outq_free+0x15/0x20 [ 63.626552] sctp_association_free+0x2d0/0x930 [ 63.631103] ? sctp_asconf_queue_teardown+0x700/0x700 [ 63.636259] ? sock_def_wakeup+0x222/0x350 [ 63.640459] ? sk_dst_check+0x560/0x560 [ 63.644416] sctp_do_sm+0x28e7/0x6dd0 [ 63.648197] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 63.654226] ? print_irqtrace_events+0x270/0x270 [ 63.658948] ? __lock_acquire+0x6aa/0x3d50 [ 63.663154] ? print_irqtrace_events+0x270/0x270 [ 63.667891] ? find_held_lock+0x35/0x1d0 [ 63.671925] ? skb_dequeue+0x12a/0x180 [ 63.675778] ? lock_downgrade+0x990/0x990 [ 63.679898] ? do_raw_spin_trylock+0x190/0x190 [ 63.684451] ? mark_held_locks+0xaf/0x100 [ 63.688572] ? trace_hardirqs_on+0xd/0x10 [ 63.692693] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 63.697247] sctp_close+0x3c6/0x980 [ 63.700850] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 63.706092] ? __lock_acquire+0x6aa/0x3d50 [ 63.710293] ? check_noncircular+0x20/0x20 [ 63.714496] ? __lock_acquire+0x6aa/0x3d50 [ 63.718695] ? check_noncircular+0x20/0x20 [ 63.722901] ? locks_remove_file+0x3fa/0x5a0 [ 63.727278] ? fcntl_setlk+0x10c0/0x10c0 [ 63.731310] ? __fsnotify_parent+0xb4/0x3a0 [ 63.735598] ? ip_mc_drop_socket+0x1ce/0x230 [ 63.739975] inet_release+0xed/0x1c0 [ 63.743658] sock_release+0x8d/0x1e0 [ 63.747337] ? sock_release+0x1e0/0x1e0 [ 63.751277] sock_close+0x16/0x20 [ 63.754695] __fput+0x327/0x7e0 [ 63.757946] ? fput+0x140/0x140 [ 63.761198] ? _raw_spin_unlock_irq+0x27/0x70 [ 63.765662] ____fput+0x15/0x20 [ 63.768909] task_work_run+0x199/0x270 [ 63.772764] ? task_work_cancel+0x210/0x210 [ 63.777053] ? __do_page_fault+0x3d6/0xd60 [ 63.781260] get_signal+0x1343/0x16d0 [ 63.785033] ? mm_fault_error+0x2c0/0x2c0 [ 63.789150] ? ptrace_notify+0x130/0x130 [ 63.793179] ? check_noncircular+0x20/0x20 [ 63.797379] ? __do_page_fault+0xd60/0xd60 [ 63.801577] ? do_page_fault+0xee/0x720 [ 63.805518] ? __do_page_fault+0xd60/0xd60 [ 63.809719] ? check_noncircular+0x20/0x20 [ 63.813921] ? find_held_lock+0x35/0x1d0 [ 63.817953] ? retint_kernel+0x10/0x10 [ 63.821815] do_signal+0x94/0x1ee0 [ 63.825326] ? put_unused_fd+0x62/0x70 [ 63.829178] ? lock_downgrade+0x990/0x990 [ 63.833300] ? setup_sigcontext+0x7d0/0x7d0 [ 63.837600] ? do_raw_spin_trylock+0x190/0x190 [ 63.842153] ? __put_unused_fd+0x183/0x250 [ 63.846356] ? alloc_fdtable+0x280/0x280 [ 63.850381] ? cpumask_weight.constprop.3+0x45/0x45 [ 63.855364] ? _copy_to_user+0xa2/0xc0 [ 63.859223] ? _raw_spin_unlock+0x22/0x30 [ 63.863345] ? fput+0xd2/0x140 [ 63.866507] ? SYSC_accept4+0x4ec/0x850 [ 63.870453] ? exit_to_usermode_loop+0x8c/0x310 [ 63.875093] exit_to_usermode_loop+0x214/0x310 [ 63.879643] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 63.885145] ? _raw_spin_unlock_irq+0x27/0x70 [ 63.889609] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 63.894595] syscall_return_slowpath+0x42f/0x510 [ 63.899316] ? finish_task_switch+0x1aa/0x740 [ 63.903776] ? prepare_exit_to_usermode+0x2d0/0x2d0 [ 63.908759] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 63.913653] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 63.918635] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 63.923364] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 63.928085] RIP: 0033:0x445e39 [ 63.931241] RSP: 002b:00007f38488b5dc8 EFLAGS: 00000202 ORIG_RAX: 0000000000000120 [ 63.938915] RAX: fffffffffffffff2 RBX: 0000000000000000 RCX: 0000000000445e39 [ 63.946149] RDX: 0000000020137ffc RSI: 0000000020b53ff0 RDI: 0000000000000003 [ 63.953383] RBP: 0000000000000000 R08: 00007f38488b6700 R09: 00007f38488b6700 [ 63.960619] R10: 0000000000080000 R11: 0000000000000202 R12: 0000000000000000 [ 63.967863] R13: 00000000007efe6f R14: 00007f38488b69c0 R15: 0000000000000000 [ 63.975294] Dumping ftrace buffer: [ 63.978862] (ftrace buffer empty) [ 63.982538] Kernel Offset: disabled [ 63.986137] Rebooting in 86400 seconds..