============================================
WARNING: possible recursive locking detected
syzkaller #0 Tainted: G             L     
--------------------------------------------
syz.4.2340/15134 is trying to acquire lock:
ffff88804cf1a160 (&rmidi->open_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
ffff88804cf1a160 (&rmidi->open_mutex){+.+.}-{4:4}, at: rawmidi_release_priv+0x45/0x280 sound/core/rawmidi.c:574

but task is already holding lock:
ffff8880551abd60 (&rmidi->open_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
ffff8880551abd60 (&rmidi->open_mutex){+.+.}-{4:4}, at: rawmidi_release_priv+0x45/0x280 sound/core/rawmidi.c:574

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

       CPU0
       ----
  lock(&rmidi->open_mutex);
  lock(&rmidi->open_mutex);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

locks held by syz.4.2340/15134: 2, last CPU#1:
 #0: ffff8880551abd60 (&rmidi->open_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
 #0: ffff8880551abd60 (&rmidi->open_mutex){+.+.}-{4:4}, at: rawmidi_release_priv+0x45/0x280 sound/core/rawmidi.c:574
 #1: ffff88804cf1a460 (&ump->open_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
 #1: ffff88804cf1a460 (&ump->open_mutex){+.+.}-{4:4}, at: snd_ump_legacy_close+0x117/0x300 sound/core/ump.c:1182

stack backtrace:
CPU: 1 UID: 0 PID: 15134 Comm: syz.4.2340 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_deadlock_bug.cold+0xbd/0xca kernel/locking/lockdep.c:3057
 check_deadlock kernel/locking/lockdep.c:3109 [inline]
 validate_chain kernel/locking/lockdep.c:3911 [inline]
 __lock_acquire+0x1343/0x1ec0 kernel/locking/lockdep.c:5253
 lock_acquire kernel/locking/lockdep.c:5886 [inline]
 lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5843
 __mutex_lock_common kernel/locking/mutex.c:646 [inline]
 __mutex_lock+0x1a4/0x1bc0 kernel/locking/mutex.c:821
 class_mutex_constructor include/linux/mutex.h:253 [inline]
 rawmidi_release_priv+0x45/0x280 sound/core/rawmidi.c:574
 snd_rawmidi_kernel_release+0x3a/0xd0 sound/core/rawmidi.c:596
 snd_ump_legacy_close+0x234/0x300 sound/core/ump.c:1187
 close_substream.part.0+0x16b/0x860 sound/core/rawmidi.c:560
 close_substream include/linux/mutex.h:253 [inline]
 rawmidi_release_priv+0x210/0x280 sound/core/rawmidi.c:580
 snd_rawmidi_release+0x5a/0xf0 sound/core/rawmidi.c:610
 __fput+0x3ff/0xb50 fs/file_table.c:512
 task_work_run+0x150/0x240 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x1d8/0x700 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline]
 do_syscall_64+0x661/0x790 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2e8979e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2e879f6028 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f2e89a25fa0 RCX: 00007f2e8979e0d9
RDX: 0100000000000000 RSI: ffffffffffffffff RDI: 0000000000000000
RBP: 00007f2e89835024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2e89a26038 R14: 00007f2e89a25fa0 R15: 00007ffce3c71da8
 </TASK>