EXT4-fs (loop6): unmounting filesystem 00000000-0000-0000-0000-000000000000.
==================================================================
BUG: KCSAN: data-race in __lru_add_drain_all / folios_put_refs

write to 0xffff888237c25a28 of 1 bytes by task 2659 on cpu 0:
 folio_batch_reinit include/linux/pagevec.h:50 [inline]
 folios_put_refs+0x272/0x2b0 mm/swap.c:986
 folios_put include/linux/mm.h:1622 [inline]
 folio_batch_move_lru+0x20b/0x230 mm/swap.c:175
 __folio_batch_add_and_move mm/swap.c:196 [inline]
 folio_add_lru+0x148/0x1f0 mm/swap.c:505
 shmem_alloc_and_add_folio mm/shmem.c:1952 [inline]
 shmem_get_folio_gfp+0x79e/0xd30 mm/shmem.c:2533
 shmem_get_folio mm/shmem.c:2639 [inline]
 shmem_write_begin+0xa7/0x190 mm/shmem.c:3289
 generic_perform_write+0x189/0x4b0 mm/filemap.c:4102
 shmem_file_write_iter+0xc2/0xe0 mm/shmem.c:3464
 __kernel_write_iter+0x243/0x4c0 fs/read_write.c:617
 dump_emit_page fs/coredump.c:885 [inline]
 dump_user_range+0x5ed/0x8b0 fs/coredump.c:959
 elf_core_dump+0x1d61/0x1ef0 fs/binfmt_elf.c:2128
 do_coredump+0x1814/0x1f50 fs/coredump.c:759
 get_signal+0xdb7/0x1080 kernel/signal.c:3019
 arch_do_signal_or_restart+0x9a/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:329 [inline]
 irqentry_exit_to_user_mode+0xa7/0x120 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 0xffff888237c25a28 of 1 bytes by task 28823 on cpu 1:
 folio_batch_count include/linux/pagevec.h:56 [inline]
 cpu_needs_drain mm/swap.c:773 [inline]
 __lru_add_drain_all+0x136/0x3f0 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+0x65b/0x910 fs/ext4/super.c:1343
 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:7393
 deactivate_locked_super+0x7d/0x1c0 fs/super.c:473
 deactivate_super+0x9f/0xb0 fs/super.c:506
 cleanup_mnt+0x26e/0x2e0 fs/namespace.c:1435
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1442
 task_work_run+0x13c/0x1b0 kernel/task_work.c:227
 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/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x1f -> 0x03

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 28823 Comm: syz-executor Not tainted 6.14.0-syzkaller-13524-gf4d2ef48250a #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================
EXT4-fs (loop6): unmounting filesystem 00000000-0000-0000-0000-000000000000.