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BUG: KCSAN: data-race in __lru_add_drain_all / folios_put_refs

write to 0xffff888237c25e68 of 1 bytes by task 4542 on cpu 0:
 folio_batch_reinit include/linux/pagevec.h:50 [inline]
 folios_put_refs+0x285/0x2d0 mm/swap.c:986
 folios_put include/linux/mm.h:1639 [inline]
 folio_batch_move_lru+0x1fd/0x230 mm/swap.c:175
 __folio_batch_add_and_move mm/swap.c:196 [inline]
 folio_add_lru+0x14a/0x1f0 mm/swap.c:505
 migrate_folio_move mm/migrate.c:1330 [inline]
 migrate_folios_move mm/migrate.c:1666 [inline]
 migrate_pages_batch+0x10d2/0x17d0 mm/migrate.c:1913
 migrate_pages_sync mm/migrate.c:1943 [inline]
 migrate_pages+0xf5f/0x1770 mm/migrate.c:2052
 do_mbind mm/mempolicy.c:1425 [inline]
 kernel_mbind mm/mempolicy.c:1568 [inline]
 __do_sys_mbind mm/mempolicy.c:1642 [inline]
 __se_sys_mbind+0x975/0xac0 mm/mempolicy.c:1638
 __x64_sys_mbind+0x78/0x90 mm/mempolicy.c:1638
 x64_sys_call+0x14af/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:238
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237c25e68 of 1 bytes by task 3324 on cpu 1:
 folio_batch_count include/linux/pagevec.h:56 [inline]
 cpu_needs_drain mm/swap.c:773 [inline]
 __lru_add_drain_all+0x12b/0x3f0 mm/swap.c:867
 lru_add_drain_all+0x10/0x20 mm/swap.c:883
 invalidate_bdev+0x47/0x70 block/bdev.c:101
 ext4_put_super+0x624/0x7d0 fs/ext4/super.c:1343
 generic_shutdown_super+0xe6/0x210 fs/super.c:643
 kill_block_super+0x2a/0x70 fs/super.c:1760
 ext4_kill_sb+0x42/0x80 fs/ext4/super.c:7393
 deactivate_locked_super+0x72/0x1c0 fs/super.c:474
 deactivate_super+0x97/0xa0 fs/super.c:507
 cleanup_mnt+0x269/0x2e0 fs/namespace.c:1432
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1439
 task_work_run+0x12e/0x1a0 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xe4/0x100 kernel/entry/common.c:114
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x1d6/0x200 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x01 -> 0x00

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3324 Comm: syz-executor Not tainted 6.15.0-syzkaller-03645-g3d413f0cfd7e #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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