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BUG: KCSAN: data-race in queue_access_lock / snd_seq_check_queue

read to 0xffff8880b24d7724 of 1 bytes by interrupt on cpu 0:
 snd_seq_check_queue+0x59/0x200 sound/core/seq/seq_queue.c:247
 snd_seq_timer_interrupt+0x243/0x280 sound/core/seq/seq_timer.c:158
 snd_timer_process_callbacks+0x1e4/0x220 sound/core/timer.c:757
 snd_timer_interrupt sound/core/timer.c:880 [inline]
 snd_timer_interrupt+0x483/0x930 sound/core/timer.c:801
 snd_hrtimer_callback+0x18f/0x260 sound/core/hrtimer.c:50
 __run_hrtimer kernel/time/hrtimer.c:1514 [inline]
 __hrtimer_run_queues+0x274/0x5f0 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:68 [inline]
 check_access kernel/kcsan/core.c:388 [inline]
 __tsan_read8+0x6c/0x1f0 kernel/kcsan/core.c:530
 zap_pte_range mm/memory.c:1025 [inline]
 zap_pmd_range mm/memory.c:1166 [inline]
 zap_pud_range mm/memory.c:1195 [inline]
 zap_p4d_range mm/memory.c:1216 [inline]
 unmap_page_range+0x84f/0x18d0 mm/memory.c:1237
 unmap_single_vma+0x144/0x200 mm/memory.c:1282
 unmap_vmas+0xda/0x1a0 mm/memory.c:1314
 exit_mmap+0x13e/0x300 mm/mmap.c:3161
 __mmput kernel/fork.c:1079 [inline]
 mmput+0xea/0x280 kernel/fork.c:1100
 exit_mm kernel/exit.c:485 [inline]
 do_exit+0x4c9/0x18f0 kernel/exit.c:804
 do_group_exit+0xb4/0x1c0 kernel/exit.c:921
 get_signal+0x2a2/0x1320 kernel/signal.c:2734
 do_signal+0x3b/0xbf0 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop+0x250/0x2c0 arch/x86/entry/common.c:159
 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
 do_syscall_64+0x353/0x370 arch/x86/entry/common.c:300
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8880b24d7724 of 1 bytes by task 20301 on cpu 1:
 queue_access_lock+0x89/0xc0 sound/core/seq/seq_queue.c:356
 snd_seq_control_queue+0x77/0x350 sound/core/seq/seq_queue.c:719
 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_dispatch_event+0xa1/0x340 sound/core/seq/seq_clientmgr.c:913
 snd_seq_check_queue+0xeb/0x200 sound/core/seq/seq_queue.c:262
 snd_seq_enqueue_event+0x163/0x2b0 sound/core/seq/seq_queue.c:330
 snd_seq_client_enqueue_event.constprop.0+0x187/0x2a0 sound/core/seq/seq_clientmgr.c:974
 snd_seq_write+0x23f/0x4d0 sound/core/seq/seq_clientmgr.c:1093
 __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+0x17b/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/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 20301 Comm: syz-executor.1 Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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