EXT4-fs (loop4): unmounting filesystem 00000000-0000-0000-0000-000000000000.
==================================================================
BUG: KCSAN: data-race in __lru_add_drain_all / folios_put_refs

write to 0xffff888237c2ab68 of 1 bytes by task 4566 on cpu 0:
 folio_batch_reinit include/linux/pagevec.h:50 [inline]
 folios_put_refs+0x26d/0x2b0 mm/swap.c:956
 folios_put include/linux/mm.h:1547 [inline]
 folio_batch_move_lru+0x202/0x230 mm/swap.c:175
 __folio_batch_add_and_move mm/swap.c:196 [inline]
 folio_add_lru+0x145/0x1f0 mm/swap.c:482
 shmem_alloc_and_add_folio mm/shmem.c:1892 [inline]
 shmem_get_folio_gfp+0x7d6/0xd90 mm/shmem.c:2355
 shmem_get_folio mm/shmem.c:2461 [inline]
 shmem_write_begin+0xa2/0x180 mm/shmem.c:3117
 generic_perform_write+0x1a8/0x4a0 mm/filemap.c:4055
 shmem_file_write_iter+0xc2/0xe0 mm/shmem.c:3293
 new_sync_write fs/read_write.c:586 [inline]
 vfs_write+0x77f/0x920 fs/read_write.c:679
 ksys_write+0xe8/0x1b0 fs/read_write.c:731
 __do_sys_write fs/read_write.c:742 [inline]
 __se_sys_write fs/read_write.c:739 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:739
 x64_sys_call+0x287e/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237c2ab68 of 1 bytes by task 3318 on cpu 1:
 folio_batch_count include/linux/pagevec.h:56 [inline]
 cpu_needs_drain mm/swap.c:741 [inline]
 __lru_add_drain_all+0x136/0x3f0 mm/swap.c:835
 lru_add_drain_all+0x10/0x20 mm/swap.c:851
 invalidate_bdev+0x47/0x70 block/bdev.c:101
 ext4_put_super+0x571/0x840 fs/ext4/super.c:1356
 generic_shutdown_super+0xe5/0x220 fs/super.c:642
 kill_block_super+0x2a/0x70 fs/super.c:1710
 ext4_kill_sb+0x44/0x80 fs/ext4/super.c:7379
 deactivate_locked_super+0x7d/0x1c0 fs/super.c:473
 deactivate_super+0x9f/0xb0 fs/super.c:506
 cleanup_mnt+0x268/0x2e0 fs/namespace.c:1373
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1380
 task_work_run+0x13a/0x1a0 kernel/task_work.c:239
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xa8/0x120 kernel/entry/common.c:218
 do_syscall_64+0xd6/0x1c0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x1f -> 0x00

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3318 Comm: syz-executor Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================