[  OK  ] Started Getty on tty1.
[  OK  ] Started System Logging Service.
[  OK  ] Started getty on tty2-tty6 if dbus and logind are not available.
[  OK  ] Started OpenBSD Secure Shell server.


Debian GNU/Linux 9 syzkaller ttyS0

syzkaller login: [   49.937106][ T4818] systemd-udevd (4818) used greatest stack depth: 22272 bytes left
[   49.955390][ T4883] systemd-udevd (4883) used greatest stack depth: 21032 bytes left
Warning: Permanently added '10.128.0.184' (ECDSA) to the list of known hosts.
executing program
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[   56.852765][  T395] 
[   56.855241][  T395] =============================
[   56.861389][  T395] WARNING: suspicious RCU usage
[   56.866237][  T395] 5.7.0-rc7-next-20200529-syzkaller #0 Not tainted
[   56.873553][  T395] -----------------------------
[   56.878951][  T395] include/linux/radix-tree.h:176 suspicious rcu_dereference_check() usage!
[   56.887640][  T395] 
[   56.887640][  T395] other info that might help us debug this:
[   56.887640][  T395] 
[   56.898738][  T395] 
executing program
[   56.898738][  T395] rcu_scheduler_active = 2, debug_locks = 1
[   56.906797][  T395] 2 locks held by kworker/u4:4/395:
[   56.912732][  T395]  #0: ffff88821b09c138 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: process_one_work+0x844/0x1690
[   56.924951][  T395]  #1: ffffc900022d7dc0 ((work_completion)(&qrtr_ns.work)){+.+.}-{0:0}, at: process_one_work+0x878/0x1690
[   56.936800][  T395] 
[   56.936800][  T395] stack backtrace:
[   56.943357][  T395] CPU: 1 PID: 395 Comm: kworker/u4:4 Not tainted 5.7.0-rc7-next-20200529-syzkaller #0
[   56.952897][  T395] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   56.962941][  T395] Workqueue: qrtr_ns_handler qrtr_ns_worker
[   56.968813][  T395] Call Trace:
[   56.972087][  T395]  dump_stack+0x18f/0x20d
[   56.976431][  T395]  ctrl_cmd_new_lookup+0x6eb/0x7e0
[   56.981528][  T395]  ? qrtr_recvmsg+0x38a/0x810
[   56.986793][  T395]  ? node_get+0xd0/0xd0
[   56.990935][  T395]  ? rcu_read_lock_sched_held+0x9c/0xd0
[   56.997074][  T395]  ? rcu_read_lock_any_held.part.0+0x50/0x50
[   57.003030][  T395]  ? qrtr_node_lookup+0xe0/0xe0
[   57.007863][  T395]  qrtr_ns_worker+0x5a1/0x1521
[   57.012618][  T395]  ? ctrl_cmd_del_client.isra.0+0x6c0/0x6c0
[   57.018506][  T395]  ? lock_acquire+0x1f2/0x8f0
[   57.023161][  T395]  ? process_one_work+0x878/0x1690
[   57.028268][  T395]  ? rcu_read_lock_sched_held+0x9c/0xd0
[   57.033809][  T395]  ? rcu_read_lock_any_held.part.0+0x50/0x50
[   57.039778][  T395]  process_one_work+0x965/0x1690
[   57.044700][  T395]  ? lock_release+0x800/0x800
[   57.049356][  T395]  ? pwq_dec_nr_in_flight+0x310/0x310
[   57.054722][  T395]  ? rwlock_bug.part.0+0x90/0x90
[   57.059644][  T395]  worker_thread+0x96/0xe20
[   57.064133][  T395]  ? process_one_work+0x1690/0x1690
[   57.069319][  T395]  kthread+0x3b5/0x4a0
[   57.073364][  T395]  ? kthread_mod_delayed_work+0x1a0/0x1a0
[   57.079060][  T395]  ? kthread_mod_delayed_work+0x1a0/0x1a0
[   57.084770][  T395]  ret_from_fork+0x1f/0x30
[   57.097030][  T395] failed to send lookup notification
[   57.102520][  T395] failed to send lookup notification
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