syzbot

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BUG: KCSAN: data-race in cgroup_rstat_flush_locked / cgroup_rstat_updated

write to 0xffffe8ffffd193c0 of 8 bytes by task 247 on cpu 0:
 cgroup_rstat_cpu_pop_updated kernel/cgroup/rstat.c:139 [inline]
 cgroup_rstat_flush_locked+0x282/0x7f0 kernel/cgroup/rstat.c:161
 cgroup_rstat_flush_irqsafe+0x24/0x40 kernel/cgroup/rstat.c:218
 mem_cgroup_flush_stats mm/memcontrol.c:5354 [inline]
 flush_memcg_stats_work+0x34/0x60 mm/memcontrol.c:5366
 process_one_work+0x402/0x910 kernel/workqueue.c:2297
 worker_thread+0x636/0xae0 kernel/workqueue.c:2444
 kthread+0x262/0x280 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30

read to 0xffffe8ffffd193c0 of 8 bytes by task 1816 on cpu 1:
 cgroup_rstat_updated+0x53/0x1c0 kernel/cgroup/rstat.c:38
 __mod_memcg_state mm/memcontrol.c:653 [inline]
 __mod_memcg_lruvec_state mm/memcontrol.c:681 [inline]
 __mod_lruvec_state+0x7c/0xe0 mm/memcontrol.c:707
 __mod_lruvec_page_state+0xd2/0x120 mm/memcontrol.c:728
 page_add_file_rmap+0x4a/0x60 mm/rmap.c:1243
 do_set_pte+0x268/0x410 mm/memory.c:3980
 filemap_map_pages+0x51d/0x870 mm/filemap.c:3329
 do_fault_around mm/memory.c:4151 [inline]
 do_read_fault mm/memory.c:4166 [inline]
 do_fault mm/memory.c:4300 [inline]
 handle_pte_fault mm/memory.c:4558 [inline]
 __handle_mm_fault mm/memory.c:4693 [inline]
 handle_mm_fault+0xae0/0x1530 mm/memory.c:4791
 do_user_addr_fault+0x609/0xbe0 arch/x86/mm/fault.c:1390
 handle_page_fault arch/x86/mm/fault.c:1475 [inline]
 exc_page_fault+0x91/0x220 arch/x86/mm/fault.c:1531
 asm_exc_page_fault+0x1e/0x30

value changed: 0xffff888100e06010 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1816 Comm: modprobe Not tainted 5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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