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BUG: KCSAN: data-race in snd_timer_pause / snd_timer_process_callbacks

read to 0xffff8880a2d94010 of 4 bytes by task 32027 on cpu 0:
 snd_timer_pause+0x22/0x70 sound/core/timer.c:689
 seq_timer_stop sound/core/seq/seq_timer.c:331 [inline]
 snd_seq_timer_stop+0x88/0xc0 sound/core/seq/seq_timer.c:341
 snd_seq_queue_process_event sound/core/seq/seq_queue.c:673 [inline]
 snd_seq_control_queue+0x24f/0x350 sound/core/seq/seq_queue.c:724
 event_input_timer+0x2f/0x50 sound/core/seq/seq_system.c:103
 snd_seq_deliver_single_event.constprop.0+0x3e8/0x4d0 sound/core/seq/seq_clientmgr.c:638
 snd_seq_deliver_event+0x2e9/0x4c0 sound/core/seq/seq_clientmgr.c:839
 snd_seq_kernel_client_dispatch+0xef/0x110 sound/core/seq/seq_clientmgr.c:2323
 send_timer_event.isra.0+0xbf/0xf0 sound/core/seq/oss/seq_oss_timer.c:140
 snd_seq_oss_timer_stop.part.0+0x35/0x50 sound/core/seq/oss/seq_oss_timer.c:176
 snd_seq_oss_timer_stop sound/core/seq/oss/seq_oss_timer.c:174 [inline]
 snd_seq_oss_timer_start+0x14e/0x160 sound/core/seq/oss/seq_oss_timer.c:153
 old_event sound/core/seq/oss/seq_oss_event.c:113 [inline]
 snd_seq_oss_process_event+0x6ee/0xe20 sound/core/seq/oss/seq_oss_event.c:88
 insert_queue sound/core/seq/oss/seq_oss_rw.c:166 [inline]
 snd_seq_oss_write+0x194/0x510 sound/core/seq/oss/seq_oss_rw.c:135
 odev_write+0x51/0x80 sound/core/seq/oss/seq_oss.c:164
 __vfs_write+0x67/0xc0 fs/read_write.c:494
 vfs_write fs/read_write.c:558 [inline]
 vfs_write+0x18a/0x390 fs/read_write.c:542
 ksys_write+0xd5/0x1b0 fs/read_write.c:611
 __do_sys_write fs/read_write.c:623 [inline]
 __se_sys_write fs/read_write.c:620 [inline]
 __x64_sys_write+0x4c/0x60 fs/read_write.c:620
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8880a2d94010 of 4 bytes by interrupt on cpu 1:
 snd_timer_process_callbacks+0x1ac/0x220 sound/core/timer.c:747
 snd_timer_interrupt sound/core/timer.c:873 [inline]
 snd_timer_interrupt+0x483/0x930 sound/core/timer.c:794
 snd_hrtimer_callback+0x18f/0x260 sound/core/hrtimer.c:50
 __run_hrtimer kernel/time/hrtimer.c:1517 [inline]
 __hrtimer_run_queues+0x274/0x5f0 kernel/time/hrtimer.c:1579
 hrtimer_interrupt+0x22a/0x480 kernel/time/hrtimer.c:1641
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
 smp_apic_timer_interrupt+0xdc/0x280 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 __read_once_size include/linux/compiler.h:232 [inline]
 arch_atomic64_read arch/x86/include/asm/atomic64_64.h:22 [inline]
 atomic64_read include/asm-generic/atomic-instrumented.h:851 [inline]
 atomic_long_read include/asm-generic/atomic-long.h:29 [inline]
 find_watchpoint kernel/kcsan/core.c:96 [inline]
 check_access kernel/kcsan/core.c:446 [inline]
 __tsan_read8+0x34/0x100 kernel/kcsan/core.c:589
 insert_queue sound/core/seq/oss/seq_oss_rw.c:157 [inline]
 snd_seq_oss_write+0x322/0x510 sound/core/seq/oss/seq_oss_rw.c:135
 odev_write+0x51/0x80 sound/core/seq/oss/seq_oss.c:164
 __vfs_write+0x67/0xc0 fs/read_write.c:494
 vfs_write fs/read_write.c:558 [inline]
 vfs_write+0x18a/0x390 fs/read_write.c:542
 ksys_write+0xd5/0x1b0 fs/read_write.c:611
 __do_sys_write fs/read_write.c:623 [inline]
 __se_sys_write fs/read_write.c:620 [inline]
 __x64_sys_write+0x4c/0x60 fs/read_write.c:620
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 31997 Comm: syz-executor.4 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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