[  OK  ] Reached target Login Prompts.
[  OK  ] Reached target Multi-User System.
[  OK  ] Reached target Graphical Interface.
         Starting Update UTMP about System Runlevel Changes...
[  OK  ] Started Update UTMP about System Runlevel Changes.


Debian GNU/Linux 9 syzkaller ttyS0

Warning: Permanently added '10.128.0.76' (ECDSA) to the list of known hosts.
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
syzkaller login: [  554.063511][ T2540] ------------[ cut here ]------------
[  554.070385][ T2540] refcount_t: underflow; use-after-free.
[  554.091814][ T2540] WARNING: CPU: 1 PID: 2540 at lib/refcount.c:28 refcount_warn_saturate+0x15b/0x1a0
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
[  554.121521][ T2540] Kernel panic - not syncing: panic_on_warn set ...
[  554.128306][ T2540] CPU: 1 PID: 2540 Comm: kworker/1:8 Not tainted 5.8.0-rc7-syzkaller #0
[  554.136621][ T2540] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[  554.146803][ T2540] Workqueue: events do_enable_set
[  554.151826][ T2540] Call Trace:
[  554.155190][ T2540]  dump_stack+0x1f0/0x31e
[  554.159648][ T2540]  panic+0x264/0x7a0
[  554.163547][ T2540]  ? __warn+0x102/0x250
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
[  554.167703][ T2540]  ? refcount_warn_saturate+0x15b/0x1a0
[  554.173243][ T2540]  ? refcount_warn_saturate+0x15b/0x1a0
[  554.178784][ T2540]  __warn+0x227/0x250
[  554.182768][ T2540]  ? refcount_warn_saturate+0x15b/0x1a0
[  554.188383][ T2540]  report_bug+0x1b1/0x2e0
[  554.192781][ T2540]  handle_bug+0x42/0x80
[  554.196940][ T2540]  exc_invalid_op+0x16/0x40
[  554.201503][ T2540]  asm_exc_invalid_op+0x12/0x20
[  554.206361][ T2540] RIP: 0010:refcount_warn_saturate+0x15b/0x1a0
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
[  554.212508][ T2540] Code: c7 8a af 14 89 31 c0 e8 b3 f2 a8 fd 0f 0b eb 85 e8 2a 32 d7 fd c6 05 a4 d9 eb 05 01 48 c7 c7 b6 af 14 89 31 c0 e8 95 f2 a8 fd <0f> 0b e9 64 ff ff ff e8 09 32 d7 fd c6 05 84 d9 eb 05 01 48 c7 c7
[  554.232107][ T2540] RSP: 0018:ffffc90007d27c48 EFLAGS: 00010246
[  554.238174][ T2540] RAX: adb9104953f59b00 RBX: 0000000000000003 RCX: ffff8880a02d0540
[  554.246143][ T2540] RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
[  554.254113][ T2540] RBP: 0000000000000003 R08: ffffffff815dd389 R09: ffffed1015d262c0
[  554.262083][ T2540] R10: ffffed1015d262c0 R11: 0000000000000000 R12: dffffc0000000000
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
executing program
[  554.270057][ T2540] R13: ffff8880a0259118 R14: dffffc0000000000 R15: ffff8880ae9350c0
[  554.278137][ T2540]  ? vprintk_emit+0x339/0x3c0
[  554.282829][ T2540]  ? refcount_warn_saturate+0x15b/0x1a0
[  554.288376][ T2540]  do_enable_set+0x66e/0x900
[  554.292970][ T2540]  ? lock_is_held_type+0x87/0xe0
[  554.297982][ T2540]  process_one_work+0x789/0xfc0
[  554.302847][ T2540]  worker_thread+0xaa4/0x1460
[  554.307594][ T2540]  kthread+0x37e/0x3a0
[  554.311677][ T2540]  ? rcu_lock_release+0x20/0x20
[  554.316522][ T2540]  ? kthread_blkcg+0xd0/0xd0
[  554.321202][ T2540]  ret_from_fork+0x1f/0x30
[  554.326920][ T2540] Kernel Offset: disabled
[  554.331280][ T2540] Rebooting in 86400 seconds..