============================================
WARNING: possible recursive locking detected
syzkaller #0 Tainted: G             L     
--------------------------------------------
syz.9.2815/16116 is trying to acquire lock:
ffff888025f9e160 (&rmidi->open_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
ffff888025f9e160 (&rmidi->open_mutex){+.+.}-{4:4}, at: rawmidi_release_priv+0x48/0x170 sound/core/rawmidi.c:574

but task is already holding lock:
ffff8880324aa160 (&rmidi->open_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
ffff8880324aa160 (&rmidi->open_mutex){+.+.}-{4:4}, at: rawmidi_release_priv+0x48/0x170 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.9.2815/16116: 2, last CPU#1:
 #0: ffff8880324aa160 (&rmidi->open_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
 #0: ffff8880324aa160 (&rmidi->open_mutex){+.+.}-{4:4}, at: rawmidi_release_priv+0x48/0x170 sound/core/rawmidi.c:574
 #1: ffff888025f9e460 (&ump->open_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
 #1: ffff888025f9e460 (&ump->open_mutex){+.+.}-{4:4}, at: snd_ump_legacy_close+0xe5/0x320 sound/core/ump.c:1182

stack backtrace:
CPU: 1 UID: 0 PID: 16116 Comm: syz.9.2815 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_deadlock_bug+0x27a/0x290 kernel/locking/lockdep.c:3057
 check_deadlock kernel/locking/lockdep.c:3109 [inline]
 validate_chain kernel/locking/lockdep.c:3911 [inline]
 __lock_acquire+0x261c/0x2e50 kernel/locking/lockdep.c:5254
 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908
 __mutex_lock_common kernel/locking/mutex.c:646 [inline]
 __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821
 class_mutex_constructor include/linux/mutex.h:253 [inline]
 rawmidi_release_priv+0x48/0x170 sound/core/rawmidi.c:574
 snd_rawmidi_kernel_release+0x46/0xa0 sound/core/rawmidi.c:596
 snd_ump_legacy_close+0x1f7/0x320 sound/core/ump.c:1187
 close_substream+0x453/0x790 sound/core/rawmidi.c:560
 rawmidi_release_priv+0xeb/0x170 sound/core/rawmidi.c:580
 snd_rawmidi_release+0x5b/0xc0 sound/core/rawmidi.c:610
 __fput+0x418/0xa50 fs/file_table.c:512
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x73a/0x2360 kernel/exit.c:1008
 do_group_exit+0x22d/0x2f0 kernel/exit.c:1151
 get_signal+0x121b/0x12c0 kernel/signal.c:3039
 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
 exit_to_user_mode_loop+0x10e/0x770 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+0x328/0x520 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff7ff59e0d9
Code: Unable to access opcode bytes at 0x7ff7ff59e0af.
RSP: 002b:00007ff8003a60e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007ff7ff826098 RCX: 00007ff7ff59e0d9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007ff7ff82609c
RBP: 00007ff7ff826090 R08: 3fffffffffffffff R09: 0000000000000000
R10: 000000000000000a R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff7ff826128 R14: 00007ffd8c507bf0 R15: 00007ffd8c507cd8
 </TASK>