============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
kworker/u10:1/7754 is trying to acquire lock:
ffffe8ffffca3118 (&pd_list->lock){+...}-{3:3}, at: padata_do_serial+0x707/0xb80

but task is already holding lock:
ffffe8ffffca37b0 (&pd_list->lock){+...}-{3:3}, at: padata_do_serial+0x590/0xb80

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&pd_list->lock);
  lock(&pd_list->lock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

3 locks held by kworker/u10:1/7754:
 #0: ffff8881697eb148 ((wq_completion)pdecrypt_parallel){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17d0
 #1: ffffc9000844fba0 ((work_completion)(&pw->pw_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17d0
 #2: ffffe8ffffca37b0 (&pd_list->lock){+...}-{3:3}, at: padata_do_serial+0x590/0xb80

stack backtrace:
CPU: 1 UID: 0 PID: 7754 Comm: kworker/u10:1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: pdecrypt_parallel padata_parallel_worker
Call Trace:
 <TASK>
 dump_stack_lvl+0x1a9/0x280
 print_deadlock_bug+0x28b/0x2a0
 validate_chain+0x1a3d/0x2130
 __lock_acquire+0xab8/0xd20
 lock_acquire+0x11f/0x350
 _raw_spin_lock+0x2e/0x40
 padata_do_serial+0x707/0xb80
 padata_parallel_worker+0x75/0x1d0
 process_scheduled_works+0xafc/0x17d0
 worker_thread+0xda6/0x1360
 kthread+0x726/0x8b0
 ret_from_fork+0x4d3/0x870
 ret_from_fork_asm+0x1a/0x30
 </TASK>
