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BUG: KCSAN: data-race in __acct_update_integrals / vm_stat_account

read to 0xffff888092381200 of 8 bytes by interrupt on cpu 0:
 __acct_update_integrals+0x1b1/0x1e0 kernel/tsacct.c:137
 acct_account_cputime+0x4e/0x60 kernel/tsacct.c:161
 account_system_index_time+0xa2/0xb0 kernel/sched/cputime.c:175
 irqtime_account_process_tick.isra.0+0x16a/0x1b0 kernel/sched/cputime.c:389
 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
 batadv_check_known_mac_addr+0x86/0x1a0 net/batman-adv/hard-interface.c:505
 batadv_hardif_add_interface net/batman-adv/hard-interface.c:944 [inline]
 batadv_hard_if_event+0x7a6/0xa70 net/batman-adv/hard-interface.c:1034
 notifier_call_chain+0xd7/0x160 kernel/notifier.c:83
 __raw_notifier_call_chain kernel/notifier.c:361 [inline]
 raw_notifier_call_chain+0x37/0x50 kernel/notifier.c:368
 call_netdevice_notifiers_info net/core/dev.c:1893 [inline]
 call_netdevice_notifiers_info+0x9a/0x120 net/core/dev.c:1878
 call_netdevice_notifiers_extack net/core/dev.c:1905 [inline]
 call_netdevice_notifiers net/core/dev.c:1919 [inline]
 register_netdevice+0x485/0xad0 net/core/dev.c:9345
 br_dev_newlink+0x33/0xf0 net/bridge/br_netlink.c:1315
 __rtnl_newlink+0xc8d/0x1090 net/core/rtnetlink.c:3305
 rtnl_newlink+0x63/0x90 net/core/rtnetlink.c:3363
 rtnetlink_rcv_msg+0x1d3/0x500 net/core/rtnetlink.c:5424
 netlink_rcv_skb+0xb0/0x260 net/netlink/af_netlink.c:2477
 rtnetlink_rcv+0x26/0x30 net/core/rtnetlink.c:5442
 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 netlink_unicast+0x3a6/0x4d0 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0x4d3/0x8b0 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:639 [inline]
 sock_sendmsg+0x9f/0xc0 net/socket.c:659
 ____sys_sendmsg+0x49d/0x4d0 net/socket.c:2330
 ___sys_sendmsg+0xb5/0x100 net/socket.c:2384
 __sys_sendmsg+0xa0/0x160 net/socket.c:2417
 __do_sys_sendmsg net/socket.c:2426 [inline]
 __se_sys_sendmsg net/socket.c:2424 [inline]
 __x64_sys_sendmsg+0x51/0x70 net/socket.c:2424
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff888092381200 of 8 bytes by task 31125 on cpu 1:
 vm_stat_account+0x45/0x150 mm/mmap.c:3303
 mprotect_fixup+0x31f/0x510 mm/mprotect.c:440
 do_mprotect_pkey+0x3eb/0x660 mm/mprotect.c:553
 __do_sys_mprotect mm/mprotect.c:578 [inline]
 __se_sys_mprotect mm/mprotect.c:575 [inline]
 __x64_sys_mprotect+0x51/0x70 mm/mprotect.c:575
 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: 1 PID: 31125 Comm: syz-executor.4 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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