[  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 '10.128.0.86' (ECDSA) to the list of known hosts.
syzkaller login: [   85.351579][ T6803] IPVS: ftp: loaded support on port[0] = 21
executing program
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[   86.582422][ T6830] ------------[ cut here ]------------
[   86.588046][ T6830] refcount_t: addition on 0; use-after-free.
[   86.595346][ T6830] WARNING: CPU: 1 PID: 6830 at lib/refcount.c:25 refcount_warn_saturate+0x13d/0x1a0
[   86.604746][ T6830] Kernel panic - not syncing: panic_on_warn set ...
[   86.611323][ T6830] CPU: 1 PID: 6830 Comm: kworker/u5:2 Not tainted 5.8.0-syzkaller #0
[   86.619363][ T6830] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   86.629409][ T6830] Workqueue: hci0 hci_rx_work
[   86.634064][ T6830] Call Trace:
[   86.637338][ T6830]  dump_stack+0x1f0/0x31e
[   86.641655][ T6830]  panic+0x264/0x7a0
[   86.645552][ T6830]  ? __warn+0x102/0x250
[   86.649700][ T6830]  ? refcount_warn_saturate+0x13d/0x1a0
[   86.655240][ T6830]  ? refcount_warn_saturate+0x13d/0x1a0
[   86.660773][ T6830]  __warn+0x227/0x250
[   86.664754][ T6830]  ? refcount_warn_saturate+0x13d/0x1a0
[   86.670286][ T6830]  report_bug+0x1b1/0x2e0
[   86.674607][ T6830]  handle_bug+0x42/0x80
[   86.678756][ T6830]  exc_invalid_op+0x16/0x40
[   86.683261][ T6830]  asm_exc_invalid_op+0x12/0x20
[   86.688095][ T6830] RIP: 0010:refcount_warn_saturate+0x13d/0x1a0
[   86.694230][ T6830] Code: c7 c3 ca 14 89 31 c0 e8 41 c0 a9 fd 0f 0b eb a3 e8 f8 0a d8 fd c6 05 38 a8 ec 05 01 48 c7 c7 fa ca 14 89 31 c0 e8 23 c0 a9 fd <0f> 0b eb 85 e8 da 0a d8 fd c6 05 1b a8 ec 05 01 48 c7 c7 26 cb 14
[   86.713823][ T6830] RSP: 0018:ffffc90001607a70 EFLAGS: 00010246
[   86.719873][ T6830] RAX: 94a8124281310300 RBX: 0000000000000002 RCX: ffff888092562280
[   86.727838][ T6830] RDX: 0000000000000000 RSI: 0000000080000001 RDI: 0000000000000000
[   86.735802][ T6830] RBP: 0000000000000002 R08: ffffffff815e07c9 R09: ffffed1015d262c0
[   86.743761][ T6830] R10: ffffed1015d262c0 R11: 0000000000000000 R12: 0000000000000000
[   86.751721][ T6830] R13: 0000000000000000 R14: ffff8880a948e018 R15: 0000000000000001
[   86.759692][ T6830]  ? vprintk_emit+0x339/0x3c0
[   86.764373][ T6830]  l2cap_global_chan_by_psm+0x4aa/0x4e0
[   86.769916][ T6830]  l2cap_recv_frame+0x530/0x8f10
[   86.774849][ T6830]  ? hci_rx_work+0x7ae/0x9c0
[   86.779424][ T6830]  ? hci_rx_work+0x7ae/0x9c0
[   86.784007][ T6830]  ? l2cap_recv_acldata+0x743/0xf00
[   86.789198][ T6830]  hci_rx_work+0x7d7/0x9c0
[   86.793611][ T6830]  process_one_work+0x789/0xfc0
[   86.798484][ T6830]  worker_thread+0xaa4/0x1460
[   86.803159][ T6830]  ? _raw_spin_unlock_irqrestore+0x6f/0xd0
[   86.808967][ T6830]  kthread+0x37e/0x3a0
[   86.813030][ T6830]  ? rcu_lock_release+0x20/0x20
[   86.817870][ T6830]  ? kthread_blkcg+0xd0/0xd0
[   86.822455][ T6830]  ret_from_fork+0x1f/0x30
[   86.830236][ T6830] Kernel Offset: disabled
[   86.835316][ T6830] Rebooting in 86400 seconds..