syzbot

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BUG: KCSAN: data-race in queue_access_lock / snd_seq_check_queue

write to 0xffff888093292ba4 of 1 bytes by interrupt on cpu 0:
 queue_access_lock+0x80/0xb0 sound/core/seq/seq_queue.c:359
 snd_seq_control_queue+0x75/0x320 sound/core/seq/seq_queue.c:727
 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_dispatch_event+0x9d/0x300 sound/core/seq/seq_clientmgr.c:913
 snd_seq_check_queue+0xf1/0x250 sound/core/seq/seq_queue.c:264
 snd_seq_timer_interrupt+0x222/0x260 sound/core/seq/seq_timer.c:158
 snd_timer_process_callbacks+0x1eb/0x230 sound/core/timer.c:796
 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:1520 [inline]
 __hrtimer_run_queues+0x271/0x600 kernel/time/hrtimer.c:1584
 hrtimer_interrupt+0x226/0x490 kernel/time/hrtimer.c:1646
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1113 [inline]
 smp_apic_timer_interrupt+0xd8/0x270 arch/x86/kernel/apic/apic.c:1138
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60
 arch_safe_halt arch/x86/include/asm/paravirt.h:144 [inline]
 default_idle+0x21/0x170 arch/x86/kernel/process.c:697
 cpuidle_idle_call kernel/sched/idle.c:154 [inline]
 do_idle+0x1b7/0x290 kernel/sched/idle.c:269
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:361
 rest_init+0xe4/0xeb init/main.c:667
 arch_call_rest_init+0x13/0x2b
 start_kernel+0x7fe/0x823 init/main.c:1005
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242

read to 0xffff888093292ba4 of 1 bytes by task 9041 on cpu 1:
 snd_seq_check_queue+0x67/0x250 sound/core/seq/seq_queue.c:249
 snd_seq_enqueue_event+0x15a/0x2a0 sound/core/seq/seq_queue.c:333
 snd_seq_client_enqueue_event.constprop.0+0x187/0x2a0 sound/core/seq/seq_clientmgr.c:974
 snd_seq_write+0x227/0x4e0 sound/core/seq/seq_clientmgr.c:1093
 __vfs_write+0x58/0xb0 fs/read_write.c:495
 vfs_write fs/read_write.c:559 [inline]
 vfs_write+0x189/0x380 fs/read_write.c:543
 ksys_write+0x16a/0x1a0 fs/read_write.c:612
 __do_sys_write fs/read_write.c:624 [inline]
 __se_sys_write fs/read_write.c:621 [inline]
 __x64_sys_write+0x49/0x60 fs/read_write.c:621
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 9041 Comm: syz-executor.0 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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