syzbot

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BUG: KCSAN: data-race in snd_seq_oss_readq_clear / snd_seq_oss_readq_put_event

write to 0xffff888043840588 of 4 bytes by task 2562 on cpu 0:
 snd_seq_oss_readq_clear+0x35/0x90 sound/core/seq/oss/seq_oss_readq.c:77
 snd_seq_oss_reset+0x102/0x160 sound/core/seq/oss/seq_oss_init.c:445
 snd_seq_oss_release+0x6a/0x160 sound/core/seq/oss/seq_oss_init.c:412
 odev_release+0x3a/0x60 sound/core/seq/oss/seq_oss.c:140
 __fput+0x243/0x4d0 fs/file_table.c:281
 ____fput+0x11/0x20 fs/file_table.c:314
 task_work_run+0x8e/0x110 kernel/task_work.c:151
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:164 [inline]
 exit_to_user_mode_prepare+0x13c/0x170 kernel/entry/common.c:191
 syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:266
 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888043840588 of 4 bytes by task 2980 on cpu 1:
 snd_seq_oss_readq_put_event+0x38/0x130 sound/core/seq/oss/seq_oss_readq.c:146
 send_synth_event sound/core/seq/oss/seq_oss_midi.c:586 [inline]
 snd_seq_oss_midi_input+0x4ea/0x500 sound/core/seq/oss/seq_oss_midi.c:522
 snd_seq_oss_event_input+0xbc/0x100 sound/core/seq/oss/seq_oss_event.c:429
 snd_seq_deliver_single_event+0x2f5/0x4b0 sound/core/seq/seq_clientmgr.c:638
 deliver_to_subscribers sound/core/seq/seq_clientmgr.c:693 [inline]
 snd_seq_deliver_event+0x384/0x490 sound/core/seq/seq_clientmgr.c:828
 snd_seq_kernel_client_dispatch+0x16f/0x190 sound/core/seq/seq_clientmgr.c:2323
 snd_vmidi_output_work+0x16d/0x200 sound/core/seq/seq_virmidi.c:150
 process_one_work+0x3e1/0x950 kernel/workqueue.c:2272
 worker_thread+0x635/0xb90 kernel/workqueue.c:2418
 kthread+0x1fa/0x220 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 2980 Comm: kworker/1:1H Not tainted 5.10.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_highpri snd_vmidi_output_work
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