[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.380607] audit: type=1800 audit(1539173168.973:25): pid=5862 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 35.417442] audit: type=1800 audit(1539173168.983:26): pid=5862 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 35.446914] audit: type=1800 audit(1539173168.983:27): pid=5862 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [....] 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 '10.128.0.73' (ECDSA) to the list of known hosts. net.ipv6.conf.syz_tun.accept_dad = 0 syzkaller login: [ 47.919750] IPVS: ftp: loaded support on port[0] = 21 net.ipv6.conf.syz_tun.router_solicitations = 0 executing program [ 48.143404] ------------[ cut here ]------------ [ 48.148191] ODEBUG: free active (active state 1) object type: rcu_head hint: (null) [ 48.157064] WARNING: CPU: 1 PID: 0 at lib/debugobjects.c:329 debug_print_object+0x16a/0x210 [ 48.165536] Kernel panic - not syncing: panic_on_warn set ... [ 48.165536] [ 48.172996] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.19.0-rc7-next-20181010+ #91 [ 48.180777] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.190112] Call Trace: [ 48.192687] dump_stack+0x244/0x3ab [ 48.196297] ? dump_stack_print_info.cold.2+0x52/0x52 [ 48.201524] panic+0x238/0x4e7 [ 48.204700] ? add_taint.cold.5+0x16/0x16 [ 48.208832] ? __warn.cold.8+0x148/0x1ba [ 48.212894] ? __warn.cold.8+0x117/0x1ba [ 48.216935] ? debug_print_object+0x16a/0x210 [ 48.221409] __warn.cold.8+0x163/0x1ba [ 48.225278] ? debug_print_object+0x16a/0x210 [ 48.229756] report_bug+0x254/0x2d0 [ 48.233510] do_error_trap+0x11b/0x200 [ 48.237381] do_invalid_op+0x36/0x40 [ 48.241115] ? debug_print_object+0x16a/0x210 [ 48.245595] invalid_op+0x14/0x20 [ 48.249033] RIP: 0010:debug_print_object+0x16a/0x210 [ 48.254115] Code: 41 88 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 92 00 00 00 48 8b 14 dd 00 07 41 88 4c 89 fe 48 c7 c7 a0 fc 40 88 e8 a6 e0 b3 fd <0f> 0b 83 05 19 dc 5e 06 01 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f [ 48.273000] RSP: 0018:ffff8801d9b07748 EFLAGS: 00010086 [ 48.278353] RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 [ 48.285669] RDX: 0000000000000000 RSI: ffffffff8164bc15 RDI: 0000000000000005 [ 48.292923] RBP: ffff8801d9b07788 R08: ffff8801d9af2340 R09: ffffed003b5e3eda [ 48.300172] R10: ffffed003b5e3eda R11: ffff8801daf1f6d7 R12: 0000000000000001 [ 48.307461] R13: ffffffff8939a4e0 R14: 0000000000000000 R15: ffffffff88410140 [ 48.314837] ? vprintk_func+0x85/0x181 [ 48.318715] ? debug_print_object+0x16a/0x210 [ 48.323194] debug_check_no_obj_freed+0x3ae/0x58d [ 48.328029] ? debug_object_activate+0x600/0x600 [ 48.332766] ? trace_hardirqs_on+0x310/0x310 [ 48.337158] ? rt_mutex_adjust_prio_chain.cold.15+0x6c/0x6c [ 48.342867] kmem_cache_free+0x202/0x290 [ 48.346912] free_task+0x16e/0x1f0 [ 48.350445] ? arch_release_task_struct+0x10/0x10 [ 48.355272] ? atomic_notifier_call_chain+0xed/0x190 [ 48.360385] __put_task_struct+0x2e6/0x620 [ 48.364618] ? free_task+0x1f0/0x1f0 [ 48.368313] ? free_unref_page+0x960/0x960 [ 48.372544] ? __phys_addr+0xa6/0x120 [ 48.376346] finish_task_switch+0x66c/0x900 [ 48.380646] ? __switch_to_asm+0x40/0x70 [ 48.384692] ? preempt_notifier_register+0x200/0x200 [ 48.389775] ? __switch_to_asm+0x34/0x70 [ 48.393813] ? __switch_to_asm+0x34/0x70 [ 48.397851] ? __switch_to_asm+0x40/0x70 [ 48.401888] ? __switch_to_asm+0x34/0x70 [ 48.405943] ? __switch_to_asm+0x40/0x70 [ 48.409982] ? __switch_to_asm+0x34/0x70 [ 48.414031] ? __switch_to_asm+0x40/0x70 [ 48.418077] ? __switch_to_asm+0x34/0x70 [ 48.422118] ? __switch_to_asm+0x34/0x70 [ 48.426186] ? __switch_to_asm+0x40/0x70 [ 48.430243] ? __switch_to_asm+0x34/0x70 [ 48.434285] ? __switch_to_asm+0x40/0x70 [ 48.438328] ? __switch_to_asm+0x34/0x70 [ 48.442366] ? __switch_to_asm+0x40/0x70 [ 48.446409] __schedule+0x8d7/0x21d0 [ 48.450105] ? __sched_text_start+0x8/0x8 [ 48.454236] ? kvm_clock_read+0x18/0x30 [ 48.458191] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 48.463192] ? kasan_check_read+0x11/0x20 [ 48.467320] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 48.472837] ? check_preemption_disabled+0x48/0x200 [ 48.477833] ? kasan_check_write+0x14/0x20 [ 48.482049] ? sched_ttwu_pending+0xae/0x2d0 [ 48.486558] ? sched_set_stop_task+0x290/0x290 [ 48.491127] schedule_idle+0x45/0x80 [ 48.494827] do_idle+0x36e/0x5c0 [ 48.498179] ? arch_cpu_idle_exit+0x70/0x70 [ 48.502480] ? _raw_spin_unlock_irqrestore+0x6d/0xd0 [ 48.507570] ? complete+0x62/0x80 [ 48.511014] cpu_startup_entry+0x10c/0x120 [ 48.515238] ? cpu_in_idle+0x20/0x20 [ 48.518936] start_secondary+0x487/0x5f0 [ 48.522991] ? set_cpu_sibling_map+0x1890/0x1890 [ 48.527831] secondary_startup_64+0xa4/0xb0 [ 48.533104] Kernel Offset: disabled [ 48.536726] Rebooting in 86400 seconds..