syzbot

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BUG: KCSAN: data-race in __acct_update_integrals / mmap_region

read to 0xffff8881247f6a40 of 8 bytes by interrupt on cpu 1:
 __acct_update_integrals+0x1b1/0x1e0 kernel/tsacct.c:137
 acct_account_cputime+0x4e/0x60 kernel/tsacct.c:161
 account_user_time+0xb2/0xc0 kernel/sched/cputime.c:131
 irqtime_account_process_tick.isra.0+0x14e/0x1b0 kernel/sched/cputime.c:383
 account_process_tick+0x14e/0x190 kernel/sched/cputime.c:482
 update_process_times+0x29/0x80 kernel/time/timer.c:1724
 tick_sched_handle+0x75/0x100 kernel/time/tick-sched.c:167
 tick_sched_timer+0x58/0xe0 kernel/time/tick-sched.c:1310
 __run_hrtimer kernel/time/hrtimer.c:1517 [inline]
 __hrtimer_run_queues+0x274/0x5f0 kernel/time/hrtimer.c:1579
 hrtimer_interrupt+0x22a/0x480 kernel/time/hrtimer.c:1641
 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:829

write to 0xffff8881247f6a40 of 8 bytes by task 8044 on cpu 0:
 vm_stat_account mm/mmap.c:3303 [inline]
 mmap_region+0x328/0xd50 mm/mmap.c:1819
 do_mmap+0x6c8/0xba0 mm/mmap.c:1555
 do_mmap_pgoff include/linux/mm.h:2338 [inline]
 vm_mmap_pgoff+0x12d/0x190 mm/util.c:506
 ksys_mmap_pgoff+0x99/0x420 mm/mmap.c:1607
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:100 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:91 [inline]
 __x64_sys_mmap+0x2e/0x40 arch/x86/kernel/sys_x86_64.c:91
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8044 Comm: syz-fuzzer Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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