Debian GNU/Linux 9 syzkaller ttyS0

Warning: Permanently added '10.128.1.29' (ECDSA) to the list of known hosts.
executing program
syzkaller login: [   26.807511] 
[   26.809149] ======================================================
[   26.815440] WARNING: possible circular locking dependency detected
[   26.821729] 4.14.288-syzkaller #0 Not tainted
[   26.826193] ------------------------------------------------------
[   26.832482] kworker/u4:5/3530 is trying to acquire lock:
[   26.837905]  (sk_lock-AF_INET6){+.+.}, at: [<ffffffff8681dfbe>] strp_work+0x3e/0x100
[   26.845770] 
[   26.845770] but task is already holding lock:
[   26.851709]  ((&strp->work)){+.+.}, at: [<ffffffff81364f26>] process_one_work+0x6e6/0x14a0
[   26.860089] 
[   26.860089] which lock already depends on the new lock.
[   26.860089] 
[   26.868376] 
[   26.868376] the existing dependency chain (in reverse order) is:
[   26.875968] 
[   26.875968] -> #1 ((&strp->work)){+.+.}:
[   26.881527]        flush_work+0xad/0x770
[   26.885563]        __cancel_work_timer+0x321/0x460
[   26.890467]        strp_done+0x53/0xd0
[   26.894343]        kcm_ioctl+0x828/0xfb0
[   26.898377]        sock_ioctl+0x2cc/0x4c0
[   26.902503]        do_vfs_ioctl+0x75a/0xff0
[   26.906797]        SyS_ioctl+0x7f/0xb0
[   26.910662]        do_syscall_64+0x1d5/0x640
[   26.915042]        entry_SYSCALL_64_after_hwframe+0x46/0xbb
[   26.920724] 
[   26.920724] -> #0 (sk_lock-AF_INET6){+.+.}:
[   26.926502]        lock_acquire+0x170/0x3f0
[   26.930795]        lock_sock_nested+0xb7/0x100
[   26.935352]        strp_work+0x3e/0x100
[   26.939302]        process_one_work+0x793/0x14a0
[   26.944042]        worker_thread+0x5cc/0xff0
[   26.948431]        kthread+0x30d/0x420
[   26.952293]        ret_from_fork+0x24/0x30
[   26.956498] 
[   26.956498] other info that might help us debug this:
[   26.956498] 
[   26.964611]  Possible unsafe locking scenario:
[   26.964611] 
[   26.970642]        CPU0                    CPU1
[   26.975280]        ----                    ----
[   26.979916]   lock((&strp->work));
[   26.983430]                                lock(sk_lock-AF_INET6);
[   26.989717]                                lock((&strp->work));
[   26.995743]   lock(sk_lock-AF_INET6);
[   26.999515] 
[   26.999515]  *** DEADLOCK ***
[   26.999515] 
[   27.005547] 2 locks held by kworker/u4:5/3530:
[   27.010099]  #0:  ("%s""kstrp"){+.+.}, at: [<ffffffff81364ef0>] process_one_work+0x6b0/0x14a0
[   27.018764]  #1:  ((&strp->work)){+.+.}, at: [<ffffffff81364f26>] process_one_work+0x6e6/0x14a0
[   27.027577] 
[   27.027577] stack backtrace:
[   27.032047] CPU: 0 PID: 3530 Comm: kworker/u4:5 Not tainted 4.14.288-syzkaller #0
[   27.039636] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
[   27.048971] Workqueue: kstrp strp_work
[   27.052829] Call Trace:
[   27.055389]  dump_stack+0x1b2/0x281
[   27.058999]  print_circular_bug.constprop.0.cold+0x2d7/0x41e
[   27.064944]  __lock_acquire+0x2e0e/0x3f20
[   27.069066]  ? __schedule+0x893/0x1de0
[   27.072939]  ? trace_hardirqs_on+0x10/0x10
[   27.077161]  ? lock_acquire+0x170/0x3f0
[   27.081115]  ? lock_sock_nested+0x98/0x100
[   27.085329]  lock_acquire+0x170/0x3f0
[   27.089111]  ? strp_work+0x3e/0x100
[   27.092717]  lock_sock_nested+0xb7/0x100
[   27.096758]  ? strp_work+0x3e/0x100
[   27.100358]  strp_work+0x3e/0x100
[   27.103786]  process_one_work+0x793/0x14a0
[   27.10