Debian GNU/Linux 9 syzkaller ttyS0

Warning: Permanently added '10.128.0.94' (ECDSA) to the list of known hosts.
executing program
syzkaller login: [   26.601148] 
[   26.602824] ======================================================
[   26.609118] WARNING: possible circular locking dependency detected
[   26.615412] 4.14.288-syzkaller #0 Not tainted
[   26.619877] ------------------------------------------------------
[   26.626167] kworker/u4:2/166 is trying to acquire lock:
[   26.631504]  (sk_lock-AF_INET6){+.+.}, at: [<ffffffff8681dfbe>] strp_work+0x3e/0x100
[   26.639371] 
[   26.639371] but task is already holding lock:
[   26.645314]  ((&strp->work)){+.+.}, at: [<ffffffff81364f26>] process_one_work+0x6e6/0x14a0
[   26.653696] 
[   26.653696] which lock already depends on the new lock.
[   26.653696] 
[   26.661988] 
[   26.661988] the existing dependency chain (in reverse order) is:
[   26.669595] 
[   26.669595] -> #1 ((&strp->work)){+.+.}:
[   26.675129]        flush_work+0xad/0x770
[   26.679166]        __cancel_work_timer+0x321/0x460
[   26.684072]        strp_done+0x53/0xd0
[   26.687933]        kcm_ioctl+0x828/0xfb0
[   26.691970]        sock_ioctl+0x2cc/0x4c0
[   26.696094]        do_vfs_ioctl+0x75a/0xff0
[   26.700391]        SyS_ioctl+0x7f/0xb0
[   26.704252]        do_syscall_64+0x1d5/0x640
[   26.708639]        entry_SYSCALL_64_after_hwframe+0x46/0xbb
[   26.714322] 
[   26.714322] -> #0 (sk_lock-AF_INET6){+.+.}:
[   26.720100]        lock_acquire+0x170/0x3f0
[   26.724394]        lock_sock_nested+0xb7/0x100
[   26.728952]        strp_work+0x3e/0x100
[   26.732900]        process_one_work+0x793/0x14a0
[   26.737631]        worker_thread+0x5cc/0xff0
[   26.742016]        kthread+0x30d/0x420
[   26.745878]        ret_from_fork+0x24/0x30
[   26.750083] 
[   26.750083] other info that might help us debug this:
[   26.750083] 
[   26.758200]  Possible unsafe locking scenario:
[   26.758200] 
[   26.764229]        CPU0                    CPU1
[   26.768866]        ----                    ----
[   26.773503]   lock((&strp->work));
[   26.777019]                                lock(sk_lock-AF_INET6);
[   26.783311]                                lock((&strp->work));
[   26.789344]   lock(sk_lock-AF_INET6);
[   26.793118] 
[   26.793118]  *** DEADLOCK ***
[   26.793118] 
[   26.799148] 2 locks held by kworker/u4:2/166:
[   26.803635]  #0:  ("%s""kstrp"){+.+.}, at: [<ffffffff81364ef0>] process_one_work+0x6b0/0x14a0
[   26.812278]  #1:  ((&strp->work)){+.+.}, at: [<ffffffff81364f26>] process_one_work+0x6e6/0x14a0
[   26.821438] 
[   26.821438] stack backtrace:
[   26.825910] CPU: 1 PID: 166 Comm: kworker/u4:2 Not tainted 4.14.288-syzkaller #0
[   26.833435] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
[   26.842771] Workqueue: kstrp strp_work
[   26.846653] Call Trace:
[   26.849218]  dump_stack+0x1b2/0x281
[   26.852828]  print_circular_bug.constprop.0.cold+0x2d7/0x41e
[   26.858603]  __lock_acquire+0x2e0e/0x3f20
[   26.862727]  ? trace_hardirqs_on+0x10/0x10
[   26.866937]  ? trace_hardirqs_on+0x10/0x10
[   26.871145]  ? lock_acquire+0x170/0x3f0
[   26.875097]  ? lock_sock_nested+0x98/0x100
[   26.879323]  lock_acquire+0x170/0x3f0
[   26.883100]  ? strp_work+0x3e/0x100
[   26.886704]  lock_sock_nested+0xb7/0x100
[   26.890739]  ? strp_work+0x3e/0x100
[   26.894342]  strp_work+0x3e/0x100
[   26.897769]  process_one_work+0x793/0x14a0
[   26