==================================================================
BUG: KCSAN: data-race in __lru_add_drain_all / folio_batch_move_lru

write to 0xffff888237c29988 of 1 bytes by task 21361 on cpu 0:
 folio_batch_reinit include/linux/pagevec.h:48 [inline]
 folio_batch_move_lru+0x2bf/0x2f0 mm/swap.c:225
 folio_batch_add_and_move mm/swap.c:234 [inline]
 folio_add_lru+0xc4/0x120 mm/swap.c:517
 shmem_get_folio_gfp+0x98d/0xc30 mm/shmem.c:2056
 shmem_get_folio mm/shmem.c:2143 [inline]
 shmem_write_begin+0xa6/0x210 mm/shmem.c:2688
 generic_perform_write+0x1c9/0x410 mm/filemap.c:3969
 shmem_file_write_iter+0xc8/0xe0 mm/shmem.c:2865
 call_write_iter include/linux/fs.h:1956 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x4ab/0x7d0 fs/read_write.c:584
 ksys_write+0xeb/0x1a0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:646
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff888237c29988 of 1 bytes by task 3119 on cpu 1:
 folio_batch_count include/linux/pagevec.h:53 [inline]
 cpu_needs_drain mm/swap.c:795 [inline]
 __lru_add_drain_all+0x137/0x420 mm/swap.c:889
 lru_add_drain_all+0x10/0x20 mm/swap.c:905
 invalidate_bdev+0x54/0x70 block/bdev.c:86
 ext4_put_super+0x51b/0x7d0 fs/ext4/super.c:1353
 generic_shutdown_super+0xdb/0x210 fs/super.c:693
 kill_block_super+0x2a/0x60 fs/super.c:1646
 ext4_kill_sb+0x44/0x80 fs/ext4/super.c:7305
 deactivate_locked_super+0x73/0x1c0 fs/super.c:481
 deactivate_super+0x9b/0xb0 fs/super.c:514
 cleanup_mnt+0x272/0x2e0 fs/namespace.c:1254
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1261
 task_work_run+0x135/0x1a0 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xd6/0xe0 kernel/entry/common.c:171
 exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:296
 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0f -> 0x00

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3119 Comm: syz-executor.3 Not tainted 6.6.0-rc7-syzkaller-00041-g611da07b89fd #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
==================================================================