[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 90.384290][ T27] audit: type=1800 audit(1578610075.289:25): pid=9656 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 90.404325][ T27] audit: type=1800 audit(1578610075.289:26): pid=9656 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 90.425385][ T27] audit: type=1800 audit(1578610075.289:27): pid=9656 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 '10.128.0.123' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 103.118057][ T9835] ------------[ cut here ]------------ [ 103.123608][ T9835] ODEBUG: free active (active state 0) object type: work_struct hint: io_ring_file_ref_switch+0x0/0xac0 [ 103.135012][ T9835] WARNING: CPU: 1 PID: 9835 at lib/debugobjects.c:481 debug_print_object+0x168/0x250 [ 103.144462][ T9835] Kernel panic - not syncing: panic_on_warn set ... [ 103.151042][ T9835] CPU: 1 PID: 9835 Comm: syz-executor255 Not tainted 5.5.0-rc5-next-20200109-syzkaller #0 [ 103.161042][ T9835] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 103.171109][ T9835] Call Trace: [ 103.174410][ T9835] dump_stack+0x197/0x210 [ 103.178818][ T9835] ? debug_print_object+0x120/0x250 [ 103.183998][ T9835] panic+0x2e3/0x75c [ 103.187875][ T9835] ? add_taint.cold+0x16/0x16 [ 103.192546][ T9835] ? __kasan_check_write+0x14/0x20 [ 103.197655][ T9835] ? __warn.cold+0x14/0x3e [ 103.202060][ T9835] ? __warn+0xd9/0x1cf [ 103.206110][ T9835] ? debug_print_object+0x168/0x250 [ 103.211309][ T9835] __warn.cold+0x2f/0x3e [ 103.215535][ T9835] ? debug_print_object+0x168/0x250 [ 103.220720][ T9835] report_bug+0x289/0x300 [ 103.225050][ T9835] do_error_trap+0x11b/0x200 [ 103.229622][ T9835] do_invalid_op+0x37/0x50 [ 103.234023][ T9835] ? debug_print_object+0x168/0x250 [ 103.239212][ T9835] invalid_op+0x23/0x30 [ 103.243353][ T9835] RIP: 0010:debug_print_object+0x168/0x250 [ 103.249150][ T9835] 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 [ 103.268755][ T9835] RSP: 0018:ffffc90001dd7ae0 EFLAGS: 00010086 [ 103.274809][ T9835] RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 [ 103.282777][ T9835] RDX: 0000000000000000 RSI: ffffffff815e68c6 RDI: fffff520003baf4e [ 103.290744][ T9835] RBP: ffffc90001dd7b20 R08: ffff88808fd5c380 R09: ffffed1015d245c9 [ 103.298710][ T9835] R10: ffffed1015d245c8 R11: ffff8880ae922e43 R12: 0000000000000001 [ 103.306672][ T9835] R13: ffffffff89b7c580 R14: ffffffff814c4450 R15: ffff8880a94d2310 [ 103.314646][ T9835] ? __exit_umh+0x2e0/0x2e0 [ 103.319138][ T9835] ? vprintk_func+0x86/0x189 [ 103.323721][ T9835] debug_check_no_obj_freed+0x2d4/0x43f [ 103.329261][ T9835] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 103.334801][ T9835] kfree+0xf8/0x2c0 [ 103.338606][ T9835] io_sqe_files_unregister+0x1fb/0x2f0 [ 103.344073][ T9835] io_ring_ctx_wait_and_kill+0x430/0x9a0 [ 103.349709][ T9835] ? write_comp_data+0x30/0x70 [ 103.354461][ T9835] io_uring_release+0x42/0x50 [ 103.359127][ T9835] __fput+0x2ff/0x890 [ 103.363112][ T9835] ? io_ring_ctx_wait_and_kill+0x9a0/0x9a0 [ 103.368914][ T9835] ____fput+0x16/0x20 [ 103.372888][ T9835] task_work_run+0x145/0x1c0 [ 103.377479][ T9835] do_exit+0xbcb/0x2f70 [ 103.381644][ T9835] ? mm_update_next_owner+0x7c0/0x7c0 [ 103.387521][ T9835] ? up_read+0x1cd/0x810 [ 103.391787][ T9835] ? down_read_non_owner+0x490/0x490 [ 103.397059][ T9835] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 103.402511][ T9835] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 103.407972][ T9835] do_group_exit+0x135/0x360 [ 103.412564][ T9835] __x64_sys_exit_group+0x44/0x50 [ 103.417575][ T9835] do_syscall_64+0xfa/0x790 [ 103.422086][ T9835] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 103.427967][ T9835] RIP: 0033:0x43ff38 [ 103.431866][ T9835] Code: 00 00 be 3c 00 00 00 eb 19 66 0f 1f 84 00 00 00 00 00 48 89 d7 89 f0 0f 05 48 3d 00 f0 ff ff 77 21 f4 48 89 d7 44 89 c0 0f 05 <48> 3d 00 f0 ff ff 76 e0 f7 d8 64 41 89 01 eb d8 0f 1f 84 00 00 00 [ 103.451597][ T9835] RSP: 002b:00007ffdb97837c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 103.460999][ T9835] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 103.468962][ T9835] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 103.476917][ T9835] RBP: 00000000004bf7d0 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 103.484869][ T9835] R10: 0000000000000007 R11: 0000000000000246 R12: 0000000000000001 [ 103.492825][ T9835] R13: 00000000006d1180 R14: 0000000000000000 R15: 0000000000000000 [ 103.502351][ T9835] Kernel Offset: disabled [ 103.506738][ T9835] Rebooting in 86400 seconds..