==================================================================
BUG: KCSAN: data-race in __wb_update_bandwidth / percpu_counter_add_batch

read-write to 0xffff888101f99920 of 8 bytes by task 3547 on cpu 0:
 percpu_counter_add_batch+0xc9/0x140 lib/percpu_counter.c:96
 wb_stat_mod include/linux/backing-dev.h:67 [inline]
 folio_account_dirtied mm/page-writeback.c:2624 [inline]
 __folio_mark_dirty+0x28d/0x4e0 mm/page-writeback.c:2669
 mark_buffer_dirty+0x148/0x250 fs/buffer.c:1200
 __block_commit_write fs/buffer.c:2175 [inline]
 block_write_end+0x158/0x2e0 fs/buffer.c:2251
 ext4_da_do_write_end fs/ext4/inode.c:2955 [inline]
 ext4_da_write_end+0x1ad/0x860 fs/ext4/inode.c:3028
 generic_perform_write+0x267/0x410 mm/filemap.c:3941
 ext4_buffered_write_iter+0x1f6/0x370 fs/ext4/file.c:299
 ext4_file_write_iter+0x297/0xe10
 __kernel_write_iter+0x25f/0x480 fs/read_write.c:523
 dump_emit_page fs/coredump.c:888 [inline]
 dump_user_range+0x25d/0x480 fs/coredump.c:915
 elf_core_dump+0x1a8e/0x1bb0 fs/binfmt_elf.c:2077
 do_coredump+0x102a/0x1890 fs/coredump.c:764
 get_signal+0xdb5/0x10a0 kernel/signal.c:2879
 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:105 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 irqentry_exit_to_user_mode+0x9c/0x130 kernel/entry/common.c:225
 irqentry_exit+0x12/0x40 kernel/entry/common.c:328
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570

read to 0xffff888101f99920 of 8 bytes by task 16098 on cpu 1:
 percpu_counter_read include/linux/percpu_counter.h:110 [inline]
 __wb_update_bandwidth+0x83/0x5c0 mm/page-writeback.c:1461
 wb_update_bandwidth+0x55/0x70 mm/page-writeback.c:1489
 wb_update_bandwidth_workfn+0x1c/0x20 mm/backing-dev.c:405
 process_one_work kernel/workqueue.c:2633 [inline]
 process_scheduled_works+0x5b8/0xa40 kernel/workqueue.c:2706
 worker_thread+0x525/0x730 kernel/workqueue.c:2787
 kthread+0x1d7/0x210 kernel/kthread.c:388
 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

value changed: 0x00000000009db310 -> 0x00000000009db320

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 16098 Comm: kworker/u4:5 Not tainted 6.8.0-rc4-syzkaller-00034-g8d3dea210042 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Workqueue: writeback wb_update_bandwidth_workfn
==================================================================