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BUG: KCSAN: data-race in snd_pcm_oss_get_active_substream / snd_pcm_oss_set_trigger

write to 0xffff88808e606b00 of 1 bytes by task 10366 on cpu 1:
 snd_pcm_oss_set_trigger+0x270/0x490 sound/core/oss/pcm_oss.c:2097
 snd_pcm_oss_ioctl+0xce3/0x2970 sound/core/oss/pcm_oss.c:2680
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88808e606b00 of 1 bytes by task 10361 on cpu 0:
 snd_pcm_oss_get_active_substream+0xa0/0x1e0 sound/core/oss/pcm_oss.c:1100
 snd_pcm_oss_get_format sound/core/oss/pcm_oss.c:1887 [inline]
 snd_pcm_oss_set_format sound/core/oss/pcm_oss.c:1879 [inline]
 snd_pcm_oss_ioctl+0x1045/0x2970 sound/core/oss/pcm_oss.c:2617
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
 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: 10361 Comm: syz-executor.5 Not tainted 5.9.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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