syzbot

wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
kworker/u4:7/1085 is trying to acquire lock:
ffffe8ffffd265b0 (&pd_list->lock){+...}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffffe8ffffd265b0 (&pd_list->lock){+...}-{2:2}, at: padata_find_next kernel/padata.c:272 [inline]
ffffe8ffffd265b0 (&pd_list->lock){+...}-{2:2}, at: padata_reorder kernel/padata.c:325 [inline]
ffffe8ffffd265b0 (&pd_list->lock){+...}-{2:2}, at: padata_do_serial+0x644/0xa70 kernel/padata.c:395

but task is already holding lock:
ffffe8ffffc266a8 (&pd_list->lock){+...}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffffe8ffffc266a8 (&pd_list->lock){+...}-{2:2}, at: padata_reorder kernel/padata.c:316 [inline]
ffffe8ffffc266a8 (&pd_list->lock){+...}-{2:2}, at: padata_do_serial+0x4db/0xa70 kernel/padata.c:395

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/u4:7/1085:
 #0: ffff88814005cd38 ((wq_completion)pencrypt_parallel){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #0: ffff88814005cd38 ((wq_completion)pencrypt_parallel){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #1: ffffc900049afd00 ((work_completion)(&pw->pw_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #1: ffffc900049afd00 ((work_completion)(&pw->pw_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #2: ffffe8ffffc266a8 (&pd_list->lock){+...}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #2: ffffe8ffffc266a8 (&pd_list->lock){+...}-{2:2}, at: padata_reorder kernel/padata.c:316 [inline]
 #2: ffffe8ffffc266a8 (&pd_list->lock){+...}-{2:2}, at: padata_do_serial+0x4db/0xa70 kernel/padata.c:395

stack backtrace:
CPU: 0 PID: 1085 Comm: kworker/u4:7 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: pencrypt_parallel padata_parallel_worker
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 check_deadlock kernel/locking/lockdep.c:3062 [inline]
 validate_chain kernel/locking/lockdep.c:3856 [inline]
 __lock_acquire+0x5dbc/0x7d40 kernel/locking/lockdep.c:5137
 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 padata_find_next kernel/padata.c:272 [inline]
 padata_reorder kernel/padata.c:325 [inline]
 padata_do_serial+0x644/0xa70 kernel/padata.c:395
 padata_parallel_worker+0x6f/0x1c0 kernel/padata.c:168
 process_one_work kernel/workqueue.c:2653 [inline]
 process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>