============================================
WARNING: possible recursive locking detected
6.4.0-rc6-next-20230615-syzkaller #0 Not tainted
--------------------------------------------
syz-executor.0/9139 is trying to acquire lock:
ffff888018fbc618 (&new_timer->it_lock){-.-.}-{2:2}, at: itimer_delete kernel/time/posix-timers.c:1049 [inline]
ffff888018fbc618 (&new_timer->it_lock){-.-.}-{2:2}, at: exit_itimers+0x2ac/0x540 kernel/time/posix-timers.c:1109

but task is already holding lock:
ffff888018fbc618 (&new_timer->it_lock){-.-.}-{2:2}, at: __lock_timer+0x1cc/0x4d0 kernel/time/posix-timers.c:595

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

       CPU0
       ----
  lock(&new_timer->it_lock);
  lock(&new_timer->it_lock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

1 lock held by syz-executor.0/9139:
 #0: ffff888018fbc618 (&new_timer->it_lock){-.-.}-{2:2}, at: __lock_timer+0x1cc/0x4d0 kernel/time/posix-timers.c:595

stack backtrace:
CPU: 1 PID: 9139 Comm: syz-executor.0 Not tainted 6.4.0-rc6-next-20230615-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
 check_deadlock kernel/locking/lockdep.c:3070 [inline]
 validate_chain kernel/locking/lockdep.c:3863 [inline]
 __lock_acquire+0x2a33/0x5e20 kernel/locking/lockdep.c:5144
 lock_acquire.part.0+0x11c/0x370 kernel/locking/lockdep.c:5761
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162
 itimer_delete kernel/time/posix-timers.c:1049 [inline]
 exit_itimers+0x2ac/0x540 kernel/time/posix-timers.c:1109
 do_exit+0x630/0x2a30 kernel/exit.c:848
 do_group_exit+0xd4/0x2a0 kernel/exit.c:1024
 get_signal+0x249b/0x25f0 kernel/signal.c:2877
 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306
 exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
 exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297
 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f2ae7e8c389
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2ae8c97168 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f2ae7fabf80 RCX: 00007f2ae7e8c389
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000040
RBP: 00007f2ae7ed7493 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffcc27c13df R14: 00007f2ae8c97300 R15: 0000000000022000
 </TASK>