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BUG: KCSAN: data-race in snd_seq_timer_get_cur_tick / snd_seq_timer_interrupt

read to 0xffff8880ae656a98 of 4 bytes by task 2493 on cpu 0:
 snd_seq_timer_get_cur_tick+0x21/0x40 sound/core/seq/seq_timer.c:449
 update_timestamp_of_queue+0x93/0x110 sound/core/seq/seq_clientmgr.c:586
 deliver_to_subscribers sound/core/seq/seq_clientmgr.c:691 [inline]
 snd_seq_deliver_event+0x2cd/0x4c0 sound/core/seq/seq_clientmgr.c:828
 snd_seq_kernel_client_dispatch+0xef/0x110 sound/core/seq/seq_clientmgr.c:2323
 snd_vmidi_output_work+0x156/0x200 sound/core/seq/seq_virmidi.c:149
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

write to 0xffff8880ae656a98 of 4 bytes by interrupt on cpu 1:
 snd_seq_timer_update_tick sound/core/seq/seq_timer.h:58 [inline]
 snd_seq_timer_interrupt+0x202/0x280 sound/core/seq/seq_timer.c:150
 snd_timer_process_callbacks+0x1e4/0x220 sound/core/timer.c:747
 snd_timer_interrupt sound/core/timer.c:870 [inline]
 snd_timer_interrupt+0x483/0x930 sound/core/timer.c:791
 snd_hrtimer_callback+0x18f/0x260 sound/core/hrtimer.c:50
 __run_hrtimer kernel/time/hrtimer.c:1514 [inline]
 __hrtimer_run_queues+0x288/0x600 kernel/time/hrtimer.c:1576
 hrtimer_interrupt+0x22a/0x480 kernel/time/hrtimer.c:1638
 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:830
 __read_once_size include/linux/compiler.h:227 [inline]
 arch_atomic64_read arch/x86/include/asm/atomic64_64.h:22 [inline]
 atomic64_read include/asm-generic/atomic-instrumented.h:850 [inline]
 atomic_long_read include/asm-generic/atomic-long.h:28 [inline]
 find_watchpoint kernel/kcsan/core.c:64 [inline]
 __kcsan_check_watchpoint+0xba/0x180 kernel/kcsan/core.c:266
 __tsan_read8+0x15/0x30 kernel/kcsan/kcsan.c:36
 ext4_get_group_desc+0xda/0x180 fs/ext4/balloc.c:291
 recently_deleted fs/ext4/ialloc.c:678 [inline]
 find_inode_bit.isra.0+0x103/0x300 fs/ext4/ialloc.c:722
 __ext4_new_inode+0xd4b/0x3070 fs/ext4/ialloc.c:914

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 17683 Comm: syz-executor.2 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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