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BUG: KCSAN: data-race in snd_timer_pause / snd_timer_process_callbacks

write to 0xffff8880b2786b10 of 4 bytes by interrupt on cpu 0:
 snd_timer_process_callbacks+0x1b6/0x230 sound/core/timer.c:793
 snd_timer_interrupt sound/core/timer.c:919 [inline]
 snd_timer_interrupt+0x488/0x950 sound/core/timer.c:840
 snd_hrtimer_callback+0x188/0x250 sound/core/hrtimer.c:50
 __run_hrtimer kernel/time/hrtimer.c:1517 [inline]
 __hrtimer_run_queues+0x271/0x600 kernel/time/hrtimer.c:1579
 hrtimer_interrupt+0x226/0x490 kernel/time/hrtimer.c:1641
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1119 [inline]
 smp_apic_timer_interrupt+0xd8/0x270 arch/x86/kernel/apic/apic.c:1144
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 arch_local_irq_enable arch/x86/include/asm/paravirt.h:762 [inline]
 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline]
 _raw_spin_unlock_irq+0x4b/0x80 kernel/locking/spinlock.c:199
 finish_lock_switch kernel/sched/core.c:3125 [inline]
 finish_task_switch+0x7b/0x260 kernel/sched/core.c:3225
 context_switch kernel/sched/core.c:3389 [inline]
 __schedule+0x30e/0x690 kernel/sched/core.c:4082
 preempt_schedule_irq+0x53/0x80 kernel/sched/core.c:4339
 restore_regs_and_return_to_kernel+0x0/0x25
 write_comp_data+0x0/0x70 kernel/kcov.c:197
 __sanitizer_cov_trace_switch+0x45/0x70 kernel/kcov.c:310
 snd_seq_oss_process_event+0x55/0xdc0 sound/core/seq/oss/seq_oss_event.c:44
 insert_queue sound/core/seq/oss/seq_oss_rw.c:166 [inline]
 snd_seq_oss_write+0x190/0x510 sound/core/seq/oss/seq_oss_rw.c:135
 odev_write+0x4d/0x80 sound/core/seq/oss/seq_oss.c:164
 __vfs_write+0x58/0xb0 fs/read_write.c:494
 vfs_write fs/read_write.c:558 [inline]
 vfs_write+0x189/0x380 fs/read_write.c:542
 ksys_write+0xc5/0x1a0 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+0x49/0x60 fs/read_write.c:620
 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880b2786b10 of 4 bytes by task 20764 on cpu 1:
 snd_timer_pause+0x1f/0x70 sound/core/timer.c:735
 seq_timer_stop sound/core/seq/seq_timer.c:331 [inline]
 snd_seq_timer_stop+0x7c/0xb0 sound/core/seq/seq_timer.c:341
 snd_seq_queue_process_event sound/core/seq/seq_queue.c:673 [inline]
 snd_seq_control_queue+0x235/0x320 sound/core/seq/seq_queue.c:724
 event_input_timer+0x29/0x40 sound/core/seq/seq_system.c:103
 snd_seq_deliver_single_event.constprop.0+0x403/0x500 sound/core/seq/seq_clientmgr.c:638
 snd_seq_deliver_event+0x2eb/0x4b0 sound/core/seq/seq_clientmgr.c:839
 snd_seq_kernel_client_dispatch+0xe0/0x100 sound/core/seq/seq_clientmgr.c:2323
 send_timer_event.isra.0+0xc9/0x100 sound/core/seq/oss/seq_oss_timer.c:140
 snd_seq_oss_timer_stop.part.0+0x32/0x50 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+0x14d/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+0x6e0/0xdc0 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+0x190/0x510 sound/core/seq/oss/seq_oss_rw.c:135
 odev_write+0x4d/0x80 sound/core/seq/oss/seq_oss.c:164
 __vfs_write+0x58/0xb0 fs/read_write.c:494
 vfs_write fs/read_write.c:558 [inline]
 vfs_write+0x189/0x380 fs/read_write.c:542
 ksys_write+0xc5/0x1a0 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+0x49/0x60 fs/read_write.c:620
 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 20764 Comm: syz-executor.1 Not tainted 5.6.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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