============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.4.775/8851 is trying to acquire lock:
ffff88801a27eb30 (&chip->mutex){+.+.}-{3:3}, at: snd_usb_endpoint_close+0x3c/0x4c0 sound/usb/endpoint.c:964

but task is already holding lock:
ffff88801a27eb30 (&chip->mutex){+.+.}-{3:3}, at: snd_usb_endpoint_set_params+0x6d/0x2b50 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.4.775/8851:
 #0: ffff88807b2334e0 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_change_params sound/core/oss/pcm_oss.c:1112 [inline]
 #0: ffff88807b2334e0 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_get_active_substream+0x136/0x270 sound/core/oss/pcm_oss.c:1132
 #1: ffff88807b233238 (&runtime->buffer_mutex){+.+.}-{3:3}, at: snd_pcm_buffer_access_lock sound/core/pcm_native.c:696 [inline]
 #1: ffff88807b233238 (&runtime->buffer_mutex){+.+.}-{3:3}, at: snd_pcm_hw_params+0x15a/0x1c50 sound/core/pcm_native.c:735
 #2: ffff88801a27eb30 (&chip->mutex){+.+.}-{3:3}, at: snd_usb_endpoint_set_params+0x6d/0x2b50 sound/usb/endpoint.c:1362

stack backtrace:
CPU: 1 PID: 8851 Comm: syz.4.775 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 check_deadlock kernel/locking/lockdep.c:3062 [inline]
 validate_chain kernel/locking/lockdep.c:3856 [inline]
 __lock_acquire+0x5d40/0x7c80 kernel/locking/lockdep.c:5137
 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x129/0xcc0 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+0x1357/0x19c0 sound/usb/pcm.c:573
 snd_pcm_hw_params+0x835/0x1c50 sound/core/pcm_native.c:779
 snd_pcm_oss_change_params_locked+0x2144/0x3d30 sound/core/oss/pcm_oss.c:976
 snd_pcm_oss_change_params sound/core/oss/pcm_oss.c:1115 [inline]
 snd_pcm_oss_get_active_substream+0x1dd/0x270 sound/core/oss/pcm_oss.c:1132
 snd_pcm_oss_get_formats+0x35/0x400 sound/core/oss/pcm_oss.c:1854
 snd_pcm_oss_set_format+0x42/0x500 sound/core/oss/pcm_oss.c:1896
 snd_pcm_oss_ioctl+0xbe4/0xdd0 sound/core/oss/pcm_oss.c:2662
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f099b38f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f09995f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f099b5e5fa0 RCX: 00007f099b38f749
RDX: 0000200000000200 RSI: 00000000c0045005 RDI: 0000000000000004
RBP: 00007f099b413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f099b5e6038 R14: 00007f099b5e5fa0 R15: 00007ffed4998398
 </TASK>