[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 77.387425][ T27] audit: type=1800 audit(1578633846.906:25): pid=9395 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 77.420924][ T27] audit: type=1800 audit(1578633846.906:26): pid=9395 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 77.451727][ T27] audit: type=1800 audit(1578633846.906:27): pid=9395 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 '10.128.0.154' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 95.301350][ T9547] ------------[ cut here ]------------ [ 95.306872][ T9547] ODEBUG: free active (active state 0) object type: work_struct hint: io_ring_file_ref_switch+0x0/0xac0 [ 95.318273][ T9547] WARNING: CPU: 1 PID: 9547 at lib/debugobjects.c:481 debug_print_object+0x168/0x250 [ 95.327728][ T9547] Kernel panic - not syncing: panic_on_warn set ... [ 95.334353][ T9547] CPU: 1 PID: 9547 Comm: syz-executor829 Not tainted 5.5.0-rc5-next-20200109-syzkaller #0 [ 95.344230][ T9547] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 95.354276][ T9547] Call Trace: [ 95.357556][ T9547] dump_stack+0x197/0x210 [ 95.361906][ T9547] ? debug_print_object+0x120/0x250 [ 95.367082][ T9547] panic+0x2e3/0x75c [ 95.371006][ T9547] ? add_taint.cold+0x16/0x16 [ 95.375665][ T9547] ? __kasan_check_write+0x14/0x20 [ 95.380756][ T9547] ? __warn.cold+0x14/0x3e [ 95.385165][ T9547] ? __warn+0xd9/0x1cf [ 95.389210][ T9547] ? debug_print_object+0x168/0x250 [ 95.394385][ T9547] __warn.cold+0x2f/0x3e [ 95.398622][ T9547] ? debug_print_object+0x168/0x250 [ 95.403800][ T9547] report_bug+0x289/0x300 [ 95.408116][ T9547] do_error_trap+0x11b/0x200 [ 95.412686][ T9547] do_invalid_op+0x37/0x50 [ 95.417079][ T9547] ? debug_print_object+0x168/0x250 [ 95.422254][ T9547] invalid_op+0x23/0x30 [ 95.426389][ T9547] RIP: 0010:debug_print_object+0x168/0x250 [ 95.432189][ T9547] Code: dd 80 8c 91 88 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 b5 00 00 00 48 8b 14 dd 80 8c 91 88 48 c7 c7 e0 81 91 88 e8 c7 95 a2 fd <0f> 0b 83 05 03 f8 00 07 01 48 83 c4 20 5b 41 5c 41 5d 41 5e 5d c3 [ 95.451805][ T9547] RSP: 0018:ffffc90001df7ae0 EFLAGS: 00010086 [ 95.457852][ T9547] RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 [ 95.465803][ T9547] RDX: 0000000000000000 RSI: ffffffff815e68c6 RDI: fffff520003bef4e [ 95.473756][ T9547] RBP: ffffc90001df7b20 R08: ffff88809110c580 R09: ffffed1015d245c9 [ 95.481713][ T9547] R10: ffffed1015d245c8 R11: ffff8880ae922e43 R12: 0000000000000001 [ 95.489663][ T9547] R13: ffffffff89b7c580 R14: ffffffff814c4450 R15: ffff88809fbaa968 [ 95.497626][ T9547] ? __exit_umh+0x2e0/0x2e0 [ 95.502126][ T9547] ? vprintk_func+0x86/0x189 [ 95.506701][ T9547] debug_check_no_obj_freed+0x2d4/0x43f [ 95.512236][ T9547] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 95.517775][ T9547] kfree+0xf8/0x2c0 [ 95.521573][ T9547] io_sqe_files_unregister+0x1fb/0x2f0 [ 95.527026][ T9547] io_ring_ctx_wait_and_kill+0x430/0x9a0 [ 95.532636][ T9547] ? write_comp_data+0x30/0x70 [ 95.537381][ T9547] io_uring_release+0x42/0x50 [ 95.542038][ T9547] __fput+0x2ff/0x890 [ 95.546002][ T9547] ? io_ring_ctx_wait_and_kill+0x9a0/0x9a0 [ 95.551788][ T9547] ____fput+0x16/0x20 [ 95.555773][ T9547] task_work_run+0x145/0x1c0 [ 95.560358][ T9547] do_exit+0xbcb/0x2f70 [ 95.564525][ T9547] ? mm_update_next_owner+0x7c0/0x7c0 [ 95.569892][ T9547] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 95.575423][ T9547] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 95.580873][ T9547] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 95.586331][ T9547] do_group_exit+0x135/0x360 [ 95.591052][ T9547] __x64_sys_exit_group+0x44/0x50 [ 95.596066][ T9547] do_syscall_64+0xfa/0x790 [ 95.600558][ T9547] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 95.606447][ T9547] RIP: 0033:0x43f888 [ 95.610332][ T9547] Code: Bad RIP value. [ 95.614379][ T9547] RSP: 002b:00007ffc8675c458 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 95.622768][ T9547] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043f888 [ 95.630719][ T9547] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 95.638687][ T9547] RBP: 00000000004bf748 R08: 00000000000000e7 R09: ffffffffffffffd4 [ 95.646644][ T9547] R10: 40000000000000a1 R11: 0000000000000246 R12: 0000000000000001 [ 95.654606][ T9547] R13: 00000000006d1180 R14: 0000000000000000 R15: 0000000000000000 [ 95.664095][ T9547] Kernel Offset: disabled [ 95.668478][ T9547] Rebooting in 86400 seconds..