==================================================================
BUG: KCSAN: data-race in snd_seq_oss_readq_put_timestamp / snd_seq_oss_readq_put_timestamp

write to 0xffff88810d291120 of 8 bytes by task 2138 on cpu 1:
 snd_seq_oss_readq_put_timestamp+0x2a0/0x2c0 sound/core/seq/oss/seq_oss_readq.c:233
 send_midi_event sound/core/seq/oss/seq_oss_midi.c:600 [inline]
 snd_seq_oss_midi_input+0x29f/0x500 sound/core/seq/oss/seq_oss_midi.c:524
 snd_seq_oss_event_input+0xbc/0x100 sound/core/seq/oss/seq_oss_event.c:429
 snd_seq_deliver_single_event+0x31e/0x4f0 sound/core/seq/seq_clientmgr.c:637
 deliver_to_subscribers sound/core/seq/seq_clientmgr.c:692 [inline]
 snd_seq_deliver_event+0x38d/0x4a0 sound/core/seq/seq_clientmgr.c:827
 snd_seq_kernel_client_dispatch+0x16f/0x190 sound/core/seq/seq_clientmgr.c:2322
 snd_vmidi_output_work+0x16d/0x200 sound/core/seq/seq_virmidi.c:150
 process_one_work+0x3e1/0x950 kernel/workqueue.c:2275
 worker_thread+0x616/0xa70 kernel/workqueue.c:2421
 kthread+0x20b/0x230 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

read to 0xffff88810d291120 of 8 bytes by task 2020 on cpu 0:
 snd_seq_oss_readq_put_timestamp+0x28/0x2c0 sound/core/seq/oss/seq_oss_readq.c:218
 send_midi_event sound/core/seq/oss/seq_oss_midi.c:600 [inline]
 snd_seq_oss_midi_input+0x29f/0x500 sound/core/seq/oss/seq_oss_midi.c:524
 snd_seq_oss_event_input+0xbc/0x100 sound/core/seq/oss/seq_oss_event.c:429
 snd_seq_deliver_single_event+0x31e/0x4f0 sound/core/seq/seq_clientmgr.c:637
 deliver_to_subscribers sound/core/seq/seq_clientmgr.c:692 [inline]
 snd_seq_deliver_event+0x38d/0x4a0 sound/core/seq/seq_clientmgr.c:827
 snd_seq_kernel_client_dispatch+0x16f/0x190 sound/core/seq/seq_clientmgr.c:2322
 snd_vmidi_output_work+0x16d/0x200 sound/core/seq/seq_virmidi.c:150
 process_one_work+0x3e1/0x950 kernel/workqueue.c:2275
 worker_thread+0x616/0xa70 kernel/workqueue.c:2421
 kthread+0x20b/0x230 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 2020 Comm: kworker/0:1H Tainted: G        W         5.12.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_highpri snd_vmidi_output_work
==================================================================
blk_update_request: I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
blk_update_request: I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0