syzbot

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BUG: KCSAN: data-race in snd_seq_oss_midi_close / snd_seq_oss_midi_open

write to 0xffff888105bdd1c0 of 8 bytes by task 30387 on cpu 1:
 snd_seq_oss_midi_close+0x263/0x2a0 sound/core/seq/oss/seq_oss_midi.c:409
 snd_seq_oss_midi_cleanup+0x3b/0x80 sound/core/seq/oss/seq_oss_midi.c:281
 snd_seq_oss_release+0x7a/0x160 sound/core/seq/oss/seq_oss_init.c:415
 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 0xffff888105bdd1c0 of 8 bytes by task 30391 on cpu 0:
 snd_seq_oss_midi_open+0xd4/0x3b0 sound/core/seq/oss/seq_oss_midi.c:325
 snd_seq_oss_process_event+0x5b3/0xf40 sound/core/seq/oss/seq_oss_event.c:69
 insert_queue sound/core/seq/oss/seq_oss_rw.c:166 [inline]
 snd_seq_oss_write+0x319/0x550 sound/core/seq/oss/seq_oss_rw.c:135
 odev_write+0x45/0x60 sound/core/seq/oss/seq_oss.c:164
 vfs_write+0x21a/0x7c0 fs/read_write.c:603
 ksys_write+0xce/0x180 fs/read_write.c:658
 __do_sys_write fs/read_write.c:670 [inline]
 __se_sys_write fs/read_write.c:667 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:667
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 30391 Comm: syz-executor.1 Not tainted 5.10.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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