==================================================================
BUG: KCSAN: data-race in snd_seq_prioq_cell_out / snd_seq_timer_interrupt

write to 0xffff888121277198 of 4 bytes by interrupt on cpu 0:
 snd_seq_timer_update_tick sound/core/seq/seq_timer.h:58 [inline]
 snd_seq_timer_interrupt+0x1e4/0x260 sound/core/seq/seq_timer.c:150
 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:1517 [inline]
 __hrtimer_run_queues+0x271/0x600 kernel/time/hrtimer.c:1579
 hrtimer_interrupt+0x226/0x490 kernel/time/hrtimer.c:1641
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1119 [inline]
 smp_apic_timer_interrupt+0xd8/0x270 arch/x86/kernel/apic/apic.c:1144
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 matching_access kernel/kcsan/encoding.h:90 [inline]
 find_watchpoint kernel/kcsan/core.c:126 [inline]
 check_access kernel/kcsan/core.c:545 [inline]
 __tsan_read8+0x27/0x100 kernel/kcsan/core.c:694
 unlock_page_memcg+0x17/0x30 mm/memcontrol.c:2028
 page_remove_file_rmap mm/rmap.c:1273 [inline]
 page_remove_rmap+0x36a/0x790 mm/rmap.c:1330
 zap_pte_range mm/memory.c:1080 [inline]
 zap_pmd_range mm/memory.c:1184 [inline]
 zap_pud_range mm/memory.c:1213 [inline]
 zap_p4d_range mm/memory.c:1234 [inline]
 unmap_page_range+0xb99/0x1a60 mm/memory.c:1255
 unmap_single_vma+0x13c/0x1f0 mm/memory.c:1300
 unmap_vmas+0xe2/0x1b0 mm/memory.c:1332
 exit_mmap+0x13e/0x2f0 mm/mmap.c:3130
 __mmput kernel/fork.c:1088 [inline]
 mmput+0xe2/0x260 kernel/fork.c:1109
 exit_mm kernel/exit.c:485 [inline]
 do_exit+0x640/0x1880 kernel/exit.c:788
 do_group_exit+0xae/0x1a0 kernel/exit.c:899
 get_signal+0x2a7/0x1290 kernel/signal.c:2734
 do_signal+0x2b/0x670 arch/x86/kernel/signal.c:813
 exit_to_usermode_loop+0x24a/0x2c0 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x36e/0x390 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888121277198 of 4 bytes by task 8197 on cpu 1:
 event_is_ready sound/core/seq/seq_prioq.c:205 [inline]
 snd_seq_prioq_cell_out+0x7b/0x200 sound/core/seq/seq_prioq.c:225
 snd_seq_check_queue+0xd6/0x210 sound/core/seq/seq_queue.c:258
 snd_seq_enqueue_event+0x15a/0x2a0 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+0x227/0x4e0 sound/core/seq/seq_clientmgr.c:1093
 __vfs_write+0x58/0xb0 fs/read_write.c:494
 vfs_write fs/read_write.c:558 [inline]
 vfs_write+0x189/0x380 fs/read_write.c:542
 ksys_write+0x16a/0x1a0 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+0x49/0x60 fs/read_write.c:620
 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8197 Comm: syz-executor.5 Not tainted 5.6.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================