syzbot

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BUG: KCSAN: data-race in __count_memcg_events / mem_cgroup_css_rstat_flush

write to 0xffffe8ffffc494c0 of 4 bytes by task 49 on cpu 1:
 mem_cgroup_css_rstat_flush+0x4ea/0x540 mm/memcontrol.c:5848
 cgroup_rstat_flush_locked+0x848/0x980 kernel/cgroup/rstat.c:245
 cgroup_rstat_flush+0x26/0x40 kernel/cgroup/rstat.c:277
 do_flush_stats mm/memcontrol.c:745 [inline]
 flush_memcg_stats_dwork+0x50/0x90 mm/memcontrol.c:782
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0x465/0x990 kernel/workqueue.c:3335
 worker_thread+0x526/0x730 kernel/workqueue.c:3416
 kthread+0x1d1/0x210 kernel/kthread.c:388
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

read-write to 0xffffe8ffffc494c0 of 4 bytes by task 7341 on cpu 0:
 memcg_rstat_updated mm/memcontrol.c:725 [inline]
 __count_memcg_events+0xce/0x130 mm/memcontrol.c:962
 count_memcg_events include/linux/memcontrol.h:1096 [inline]
 count_memcg_event_mm include/linux/memcontrol.h:1120 [inline]
 mm_account_fault mm/memory.c:5475 [inline]
 handle_mm_fault+0x14da/0x27e0 mm/memory.c:5622
 do_user_addr_fault arch/x86/mm/fault.c:1413 [inline]
 handle_page_fault arch/x86/mm/fault.c:1505 [inline]
 exc_page_fault+0x2f5/0x6d0 arch/x86/mm/fault.c:1563
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
 rep_movs_alternative+0x4a/0x70 arch/x86/lib/copy_user_64.S:65
 copy_user_generic arch/x86/include/asm/uaccess_64.h:110 [inline]
 raw_copy_from_user arch/x86/include/asm/uaccess_64.h:125 [inline]
 copy_from_user_iter lib/iov_iter.c:55 [inline]
 iterate_ubuf include/linux/iov_iter.h:29 [inline]
 iterate_and_advance2 include/linux/iov_iter.h:245 [inline]
 iterate_and_advance include/linux/iov_iter.h:271 [inline]
 __copy_from_iter lib/iov_iter.c:249 [inline]
 _copy_from_iter+0x13a/0xb00 lib/iov_iter.c:260
 copy_from_iter include/linux/uio.h:204 [inline]
 copy_from_iter_full include/linux/uio.h:211 [inline]
 skb_do_copy_data_nocache include/net/sock.h:2240 [inline]
 skb_copy_to_page_nocache include/net/sock.h:2266 [inline]
 kcm_sendmsg+0x889/0x15b0 net/kcm/kcmsock.c:858
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x140/0x180 net/socket.c:745
 sock_write_iter+0x164/0x1b0 net/socket.c:1160
 call_write_iter include/linux/fs.h:2110 [inline]
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0x771/0x8e0 fs/read_write.c:590
 ksys_write+0xeb/0x1b0 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:652
 x64_sys_call+0x27b7/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000003d -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7341 Comm: syz-executor.0 Not tainted 6.9.0-rc5-syzkaller-00296-g5eb4573ea63d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
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