============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.3.273/6944 is trying to acquire lock:
ffff888077e96b30 (&chip->mutex){+.+.}-{3:3}, at: snd_usb_endpoint_close+0x3c/0x4c0 sound/usb/endpoint.c:964

but task is already holding lock:
ffff888077e96b30 (&chip->mutex){+.+.}-{3:3}, at: snd_usb_endpoint_set_params+0x6d/0x2b40 sound/usb/endpoint.c:1362

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

       CPU0
       ----
  lock(&chip->mutex);
  lock(&chip->mutex);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

3 locks held by syz.3.273/6944:
 #0: ffff88807bc4a4e0 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_sync+0x2a7/0xc20 sound/core/oss/pcm_oss.c:1675
 #1: ffff88807bc4a238 (&runtime->buffer_mutex){+.+.}-{3:3}, at: snd_pcm_buffer_access_lock sound/core/pcm_native.c:696 [inline]
 #1: ffff88807bc4a238 (&runtime->buffer_mutex){+.+.}-{3:3}, at: snd_pcm_hw_params+0x163/0x1ce0 sound/core/pcm_native.c:735
 #2: ffff888077e96b30 (&chip->mutex){+.+.}-{3:3}, at: snd_usb_endpoint_set_params+0x6d/0x2b40 sound/usb/endpoint.c:1362

stack backtrace:
CPU: 1 PID: 6944 Comm: syz.3.273 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x136/0xcc0 kernel/locking/mutex.c:747
 snd_usb_endpoint_close+0x3c/0x4c0 sound/usb/endpoint.c:964
 close_endpoints sound/usb/pcm.c:454 [inline]
 snd_usb_hw_params+0x1356/0x19d0 sound/usb/pcm.c:573
 snd_pcm_hw_params+0x8a6/0x1ce0 sound/core/pcm_native.c:779
 snd_pcm_oss_change_params_locked+0x2040/0x3cd0 sound/core/oss/pcm_oss.c:976
 snd_pcm_oss_make_ready_locked sound/core/oss/pcm_oss.c:1197 [inline]
 snd_pcm_oss_sync+0x363/0xc20 sound/core/oss/pcm_oss.c:1679
 snd_pcm_oss_release+0x102/0x240 sound/core/oss/pcm_oss.c:2589
 __fput+0x234/0x970 fs/file_table.c:384
 task_work_run+0x1d4/0x260 kernel/task_work.c:245
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0x95a/0x2460 kernel/exit.c:883
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
 get_signal+0x12fc/0x13f0 kernel/signal.c:2902
 arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f7a4479acb9
Code: Unable to access opcode bytes at 0x7f7a4479ac8f.
RSP: 002b:00007f7a45586028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000010106 RBX: 00007f7a44a16090 RCX: 00007f7a4479acb9
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007f7a44808bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7a44a16128 R14: 00007f7a44a16090 R15: 00007ffe78710638
 </TASK>