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BUG: KCSAN: data-race in snd_ctl_notify / snd_ctl_notify

read to 0xffff888126448858 of 4 bytes by interrupt on cpu 0:
 snd_ctl_notify sound/core/control.c:154 [inline]
 snd_ctl_notify+0xd7/0x3b0 sound/core/control.c:141
 loopback_active_notify+0xcb/0xe0 sound/drivers/aloop.c:242
 loopback_trigger+0x59f/0x710 sound/drivers/aloop.c:296
 snd_pcm_do_stop sound/core/pcm_native.c:1279 [inline]
 snd_pcm_do_stop+0xe6/0xf0 sound/core/pcm_native.c:1275
 snd_pcm_action_single+0x5a/0xc0 sound/core/pcm_native.c:1072
 snd_pcm_action+0x83/0x90 sound/core/pcm_native.c:1155
 snd_pcm_stop+0x2e/0x40 sound/core/pcm_native.c:1312
 __snd_pcm_xrun+0x92/0x300 sound/core/pcm_lib.c:149
 snd_pcm_update_state+0x31f/0x330 sound/core/pcm_lib.c:190
 snd_pcm_update_hw_ptr0+0xa05/0x1280 sound/core/pcm_lib.c:453
 snd_pcm_period_elapsed+0x10d/0x1a0 sound/core/pcm_lib.c:1794
 loopback_timer_function+0x130/0x137 sound/drivers/aloop.c:525
 call_timer_fn+0x5f/0x2f0 kernel/time/timer.c:1404
 expire_timers kernel/time/timer.c:1449 [inline]
 __run_timers kernel/time/timer.c:1773 [inline]
 __run_timers kernel/time/timer.c:1740 [inline]
 run_timer_softirq+0xc0c/0xcd0 kernel/time/timer.c:1786
 __do_softirq+0x115/0x33f kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0xbb/0xe0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0xe6/0x280 arch/x86/kernel/apic/apic.c:1137
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
 native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60
 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:571
 default_idle_call+0x1e/0x40 kernel/sched/idle.c:94
 cpuidle_idle_call kernel/sched/idle.c:154 [inline]
 do_idle+0x1af/0x280 kernel/sched/idle.c:263
 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:355
 rest_init+0xec/0xf6 init/main.c:452
 arch_call_rest_init+0x17/0x37
 start_kernel+0x838/0x85e init/main.c:786
 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:490
 x86_64_start_kernel+0x72/0x76 arch/x86/kernel/head64.c:471
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241

write to 0xffff888126448858 of 4 bytes by interrupt on cpu 1:
 snd_ctl_notify sound/core/control.c:154 [inline]
 snd_ctl_notify+0xe9/0x3b0 sound/core/control.c:141
 loopback_active_notify+0xcb/0xe0 sound/drivers/aloop.c:242
 loopback_trigger+0x59f/0x710 sound/drivers/aloop.c:296
 snd_pcm_do_stop sound/core/pcm_native.c:1279 [inline]
 snd_pcm_do_stop+0xe6/0xf0 sound/core/pcm_native.c:1275
 snd_pcm_action_single+0x5a/0xc0 sound/core/pcm_native.c:1072
 snd_pcm_action+0x83/0x90 sound/core/pcm_native.c:1155
 snd_pcm_stop+0x2e/0x40 sound/core/pcm_native.c:1312
 __snd_pcm_xrun+0x92/0x300 sound/core/pcm_lib.c:149
 snd_pcm_update_state+0x31f/0x330 sound/core/pcm_lib.c:190
 snd_pcm_update_hw_ptr0+0xa05/0x1280 sound/core/pcm_lib.c:453
 snd_pcm_period_elapsed+0x10d/0x1a0 sound/core/pcm_lib.c:1794
 loopback_timer_function+0x130/0x137 sound/drivers/aloop.c:525
 call_timer_fn+0x5f/0x2f0 kernel/time/timer.c:1404
 expire_timers kernel/time/timer.c:1449 [inline]
 __run_timers kernel/time/timer.c:1773 [inline]
 __run_timers kernel/time/timer.c:1740 [inline]
 run_timer_softirq+0xc0c/0xcd0 kernel/time/timer.c:1786
 __do_softirq+0x115/0x33f kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0xbb/0xe0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0xe6/0x280 arch/x86/kernel/apic/apic.c:1137
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
 arch_local_irq_restore arch/x86/include/asm/paravirt.h:756 [inline]
 kcsan_setup_watchpoint+0x1d4/0x460 kernel/kcsan/core.c:436
 check_access kernel/kcsan/core.c:466 [inline]
 __tsan_read1 kernel/kcsan/core.c:593 [inline]
 __tsan_read1+0xc2/0x100 kernel/kcsan/core.c:593
 tomoyo_check_acl+0x98/0x270 security/tomoyo/domain.c:170
 tomoyo_path_permission security/tomoyo/file.c:586 [inline]
 tomoyo_path_permission+0xe3/0x160 security/tomoyo/file.c:573
 tomoyo_path_perm+0x23e/0x390 security/tomoyo/file.c:838
 tomoyo_inode_getattr+0x26/0x40 security/tomoyo/tomoyo.c:129
 security_inode_getattr+0x9b/0xd0 security/security.c:1222
 vfs_getattr+0x2e/0x70 fs/stat.c:115
 vfs_statx+0x102/0x190 fs/stat.c:191
 vfs_lstat include/linux/fs.h:3247 [inline]
 __do_sys_newlstat+0x51/0xb0 fs/stat.c:354
 __se_sys_newlstat fs/stat.c:348 [inline]
 __x64_sys_newlstat+0x3a/0x50 fs/stat.c:348
 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: 7610 Comm: udevd Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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