Debian GNU/Linux 9 syzkaller ttyS0

Warning: Permanently added '10.128.0.185' (ECDSA) to the list of known hosts.
executing program
syzkaller login: [   27.275778] 
[   27.277423] ======================================================
[   27.283715] WARNING: possible circular locking dependency detected
[   27.290005] 4.14.289-syzkaller #0 Not tainted
[   27.294466] ------------------------------------------------------
[   27.300759] kworker/u4:1/23 is trying to acquire lock:
[   27.306006]  (sk_lock-AF_INET6){+.+.}, at: [<ffffffff8681e12e>] strp_work+0x3e/0x100
[   27.313884] 
[   27.313884] but task is already holding lock:
[   27.319936]  ((&strp->work)){+.+.}, at: [<ffffffff81364ee6>] process_one_work+0x6e6/0x14a0
[   27.328324] 
[   27.328324] which lock already depends on the new lock.
[   27.328324] 
[   27.336618] 
[   27.336618] the existing dependency chain (in reverse order) is:
[   27.344212] 
[   27.344212] -> #1 ((&strp->work)){+.+.}:
[   27.349734]        flush_work+0xad/0x770
[   27.353784]        __cancel_work_timer+0x321/0x460
[   27.358694]        strp_done+0x53/0xd0
[   27.362554]        kcm_ioctl+0x828/0xfb0
[   27.366591]        sock_ioctl+0x2cc/0x4c0
[   27.370714]        do_vfs_ioctl+0x75a/0xff0
[   27.375006]        SyS_ioctl+0x7f/0xb0
[   27.378868]        do_syscall_64+0x1d5/0x640
[   27.383250]        entry_SYSCALL_64_after_hwframe+0x46/0xbb
[   27.388928] 
[   27.388928] -> #0 (sk_lock-AF_INET6){+.+.}:
[   27.394704]        lock_acquire+0x170/0x3f0
[   27.398996]        lock_sock_nested+0xb7/0x100
[   27.403550]        strp_work+0x3e/0x100
[   27.407496]        process_one_work+0x793/0x14a0
[   27.412224]        worker_thread+0x5cc/0xff0
[   27.416603]        kthread+0x30d/0x420
[   27.420463]        ret_from_fork+0x24/0x30
[   27.424665] 
[   27.424665] other info that might help us debug this:
[   27.424665] 
[   27.432786]  Possible unsafe locking scenario:
[   27.432786] 
[   27.438819]        CPU0                    CPU1
[   27.443457]        ----                    ----
[   27.448094]   lock((&strp->work));
[   27.451606]                                lock(sk_lock-AF_INET6);
[   27.457895]                                lock((&strp->work));
[   27.463921]   lock(sk_lock-AF_INET6);
[   27.467707] 
[   27.467707]  *** DEADLOCK ***
[   27.467707] 
[   27.473743] 2 locks held by kworker/u4:1/23:
[   27.478144]  #0:  ("%s""kstrp"){+.+.}, at: [<ffffffff81364eb0>] process_one_work+0x6b0/0x14a0
[   27.486791]  #1:  ((&strp->work)){+.+.}, at: [<ffffffff81364ee6>] process_one_work+0x6e6/0x14a0
[   27.495608] 
[   27.495608] stack backtrace:
[   27.500082] CPU: 1 PID: 23 Comm: kworker/u4:1 Not tainted 4.14.289-syzkaller #0
[   27.507502] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
[   27.516837] Workqueue: kstrp strp_work
[   27.520695] Call Trace:
[   27.523256]  dump_stack+0x1b2/0x281
[   27.526856]  print_circular_bug.constprop.0.cold+0x2d7/0x41e
[   27.532628]  __lock_acquire+0x2e0e/0x3f20
[   27.536845]  ? __schedule+0x893/0x1de0
[   27.540713]  ? trace_hardirqs_on+0x10/0x10
[   27.544944]  ? lock_acquire+0x170/0x3f0
[   27.548897]  ? lock_sock_nested+0x98/0x100
[   27.553112]  lock_acquire+0x170/0x3f0
[   27.556895]  ? strp_work+0x3e/0x100
[   27.560499]  lock_sock_nested+0xb7/0x100
[   27.564534]  ? strp_work+0x3e/0x100
[   27.568152]  strp_work+0x3e/0x100
[   27.571584]  process_one_work+0x793/0x14a0
[   27.575798]