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BUG: KCSAN: data-race in snd_ctl_notify / snd_ctl_notify

read to 0xffff888126886858 of 4 bytes by interrupt on cpu 1:
 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+0x141/0x1c0 sound/core/pcm_lib.c:1791
 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+0x205/0x410 kernel/kcsan/core.c:369
 check_access kernel/kcsan/core.c:409 [inline]
 __tsan_unaligned_write8+0x143/0x1f0 kernel/kcsan/core.c:530
 __tlb_remove_page_size+0x6a/0x1d0 mm/mmu_gather.c:81
 __tlb_remove_page include/asm-generic/tlb.h:414 [inline]
 zap_pte_range mm/memory.c:1065 [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+0xc08/0x18d0 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
 __do_sys_exit_group kernel/exit.c:932 [inline]
 __se_sys_exit_group kernel/exit.c:930 [inline]
 __x64_sys_exit_group+0x2e/0x30 kernel/exit.c:930
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff888126886858 of 4 bytes by interrupt on cpu 0:
 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+0x141/0x1c0 sound/core/pcm_lib.c:1791
 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
 __tlb_remove_page_size+0x6e/0x1d0 mm/mmu_gather.c:81
 __tlb_remove_page include/asm-generic/tlb.h:414 [inline]
 zap_pte_range mm/memory.c:1065 [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+0xc08/0x18d0 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
 __do_sys_exit_group kernel/exit.c:932 [inline]
 __se_sys_exit_group kernel/exit.c:930 [inline]
 __x64_sys_exit_group+0x2e/0x30 kernel/exit.c:930
 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: 0 PID: 8895 Comm: syz-executor.3 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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