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BUG: KCSAN: data-race in __lru_add_drain_all / folio_add_lru

read-write to 0xffff888237c2ac68 of 1 bytes by task 4519 on cpu 0:
 folio_batch_add include/linux/pagevec.h:77 [inline]
 __folio_batch_add_and_move mm/swap.c:239 [inline]
 folio_add_lru+0xa3/0x1f0 mm/swap.c:527
 shmem_alloc_and_add_folio mm/shmem.c:1867 [inline]
 shmem_get_folio_gfp+0x7d6/0xd90 mm/shmem.c:2330
 shmem_get_folio mm/shmem.c:2436 [inline]
 shmem_write_begin+0xa2/0x180 mm/shmem.c:3041
 generic_perform_write+0x1a8/0x4a0 mm/filemap.c:4054
 shmem_file_write_iter+0xc2/0xe0 mm/shmem.c:3216
 __kernel_write_iter+0x24b/0x4e0 fs/read_write.c:616
 dump_emit_page fs/coredump.c:884 [inline]
 dump_user_range+0x3a7/0x550 fs/coredump.c:945
 elf_core_dump+0x1b66/0x1c60 fs/binfmt_elf.c:2121
 do_coredump+0x1736/0x1ce0 fs/coredump.c:758
 get_signal+0xdc0/0x1070 kernel/signal.c:2902
 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 irqentry_exit_to_user_mode+0x9a/0x130 kernel/entry/common.c:231
 irqentry_exit+0x12/0x50 kernel/entry/common.c:334
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

read to 0xffff888237c2ac68 of 1 bytes by task 3266 on cpu 1:
 folio_batch_count include/linux/pagevec.h:56 [inline]
 cpu_needs_drain mm/swap.c:786 [inline]
 __lru_add_drain_all+0x136/0x3f0 mm/swap.c:880
 lru_add_drain_all+0x10/0x20 mm/swap.c:896
 invalidate_bdev+0x47/0x70 block/bdev.c:101
 ext4_put_super+0x571/0x840 fs/ext4/super.c:1349
 generic_shutdown_super+0xe5/0x220 fs/super.c:642
 kill_block_super+0x2a/0x70 fs/super.c:1696
 ext4_kill_sb+0x44/0x80 fs/ext4/super.c:7320
 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:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xbe/0x130 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: 0x15 -> 0x16

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3266 Comm: syz-executor Not tainted 6.12.0-rc4-syzkaller-00045-gd12937763990 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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