Debian GNU/Linux 9 syzkaller ttyS0

Warning: Permanently added '10.128.0.253' (ECDSA) to the list of known hosts.
executing program
syzkaller login: [   27.117274] 
[   27.118909] ======================================================
[   27.125198] WARNING: possible circular locking dependency detected
[   27.131484] 4.14.286-syzkaller #0 Not tainted
[   27.135946] ------------------------------------------------------
[   27.142234] kworker/u4:3/1511 is trying to acquire lock:
[   27.147778]  (sk_lock-AF_INET6){+.+.}, at: [<ffffffff8681de3e>] strp_work+0x3e/0x100
[   27.155647] 
[   27.155647] but task is already holding lock:
[   27.161590]  ((&strp->work)){+.+.}, at: [<ffffffff81364f26>] process_one_work+0x6e6/0x14a0
[   27.169973] 
[   27.169973] which lock already depends on the new lock.
[   27.169973] 
[   27.178260] 
[   27.178260] the existing dependency chain (in reverse order) is:
[   27.185854] 
[   27.185854] -> #1 ((&strp->work)){+.+.}:
[   27.191372]        flush_work+0xad/0x770
[   27.195404]        __cancel_work_timer+0x321/0x460
[   27.200307]        strp_done+0x53/0xd0
[   27.204169]        kcm_ioctl+0x828/0xfb0
[   27.208208]        sock_ioctl+0x2cc/0x4c0
[   27.212347]        do_vfs_ioctl+0x75a/0xff0
[   27.216653]        SyS_ioctl+0x7f/0xb0
[   27.220514]        do_syscall_64+0x1d5/0x640
[   27.224911]        entry_SYSCALL_64_after_hwframe+0x46/0xbb
[   27.230591] 
[   27.230591] -> #0 (sk_lock-AF_INET6){+.+.}:
[   27.236372]        lock_acquire+0x170/0x3f0
[   27.240665]        lock_sock_nested+0xb7/0x100
[   27.245227]        strp_work+0x3e/0x100
[   27.249184]        process_one_work+0x793/0x14a0
[   27.253924]        worker_thread+0x5cc/0xff0
[   27.258330]        kthread+0x30d/0x420
[   27.262191]        ret_from_fork+0x24/0x30
[   27.266393] 
[   27.266393] other info that might help us debug this:
[   27.266393] 
[   27.274506]  Possible unsafe locking scenario:
[   27.274506] 
[   27.280540]        CPU0                    CPU1
[   27.285179]        ----                    ----
[   27.289812]   lock((&strp->work));
[   27.293335]                                lock(sk_lock-AF_INET6);
[   27.299624]                                lock((&strp->work));
[   27.305652]   lock(sk_lock-AF_INET6);
[   27.309423] 
[   27.309423]  *** DEADLOCK ***
[   27.309423] 
[   27.315452] 2 locks held by kworker/u4:3/1511:
[   27.320010]  #0:  ("%s""kstrp"){+.+.}, at: [<ffffffff81364ef0>] process_one_work+0x6b0/0x14a0
[   27.328658]  #1:  ((&strp->work)){+.+.}, at: [<ffffffff81364f26>] process_one_work+0x6e6/0x14a0
[   27.337478] 
[   27.337478] stack backtrace:
[   27.341946] CPU: 0 PID: 1511 Comm: kworker/u4:3 Not tainted 4.14.286-syzkaller #0
[   27.349537] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
[   27.358877] Workqueue: kstrp strp_work
[   27.362735] Call Trace:
[   27.365301]  dump_stack+0x1b2/0x281
[   27.368905]  print_circular_bug.constprop.0.cold+0x2d7/0x41e
[   27.374675]  __lock_acquire+0x2e0e/0x3f20
[   27.378804]  ? trace_hardirqs_on+0x10/0x10
[   27.383014]  ? trace_hardirqs_on+0x10/0x10
[   27.387222]  ? lock_acquire+0x170/0x3f0
[   27.391171]  ? check_preemption_disabled+0x35/0x240
[   27.396163]  ? lock_sock_nested+0x98/0x100
[   27.400376]  lock_acquire+0x170/0x3f0
[   27.404155]  ? strp_work+0x3e/0x100
[   27.407755]  lock_sock_nested+0xb7/0x100
[   27.411793]  ? strp_work+0x3e/0x100
[   27.415394]  strp_work+0x3e/0x10