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BUG: KCSAN: data-race in kcompactd / kthread_is_per_cpu

write to 0xffff888100b5706c of 4 bytes by task 471 on cpu 1:
 freezer_do_not_count include/linux/freezer.h:109 [inline]
 freezable_schedule_timeout include/linux/freezer.h:191 [inline]
 kcompactd+0x33e/0xc10 mm/compaction.c:2906
 kthread+0x1d0/0x1f0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

read to 0xffff888100b5706c of 4 bytes by interrupt on cpu 0:
 __to_kthread kernel/kthread.c:101 [inline]
 kthread_is_per_cpu+0x2d/0x80 kernel/kthread.c:540
 can_migrate_task+0xf/0x180 kernel/sched/fair.c:7615
 detach_tasks+0xab/0x380 kernel/sched/fair.c:7779
 load_balance+0x768/0xcc0 kernel/sched/fair.c:9679
 rebalance_domains+0x1ae/0x2d0 kernel/sched/fair.c:10058
 __do_softirq+0x12c/0x275 kernel/softirq.c:559
 invoke_softirq kernel/softirq.c:433 [inline]
 __irq_exit_rcu+0xa5/0xb0 kernel/softirq.c:637
 sysvec_apic_timer_interrupt+0x69/0x80 arch/x86/kernel/apic/apic.c:1100
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:647
 get_ctx kernel/kcsan/core.c:202 [inline]
 check_access kernel/kcsan/core.c:630 [inline]
 __tsan_read4+0x117/0x180 kernel/kcsan/core.c:844
 selinux_cred security/selinux/include/objsec.h:153 [inline]
 cred_sid security/selinux/hooks.c:228 [inline]
 inode_has_perm security/selinux/hooks.c:1702 [inline]
 path_has_perm security/selinux/hooks.c:1738 [inline]
 selinux_inode_getattr+0x14d/0x210 security/selinux/hooks.c:3261
 security_inode_getattr+0x7f/0xd0 security/security.c:1332
 vfs_getattr fs/stat.c:139 [inline]
 vfs_statx+0xf8/0x290 fs/stat.c:207
 vfs_fstatat fs/stat.c:225 [inline]
 vfs_lstat include/linux/fs.h:3384 [inline]
 __do_sys_newlstat fs/stat.c:380 [inline]
 __se_sys_newlstat+0x46/0x250 fs/stat.c:374
 __x64_sys_newlstat+0x2d/0x40 fs/stat.c:374
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1032 Comm: systemd-udevd Not tainted 5.13.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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