EXT4-fs (loop5): unmounting filesystem 00000000-0000-0000-0000-000000000000.
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BUG: KCSAN: data-race in __lru_add_drain_all / folio_add_lru

read-write to 0xffff888237c25e68 of 1 bytes by task 13921 on cpu 0:
 folio_batch_add include/linux/pagevec.h:77 [inline]
 __folio_batch_add_and_move mm/swap.c:194 [inline]
 folio_add_lru+0xa5/0x1f0 mm/swap.c:505
 shmem_alloc_and_add_folio mm/shmem.c:1949 [inline]
 shmem_get_folio_gfp+0x7ab/0xd60 mm/shmem.c:2532
 shmem_get_folio mm/shmem.c:2638 [inline]
 shmem_write_begin+0xa8/0x190 mm/shmem.c:3288
 generic_perform_write+0x184/0x490 mm/filemap.c:4112
 shmem_file_write_iter+0xc5/0xf0 mm/shmem.c:3463
 __kernel_write_iter+0x253/0x4c0 fs/read_write.c:619
 dump_emit_page fs/coredump.c:1112 [inline]
 dump_user_range+0x407/0x8c0 fs/coredump.c:1186
 elf_core_dump+0x1dc2/0x1f80 fs/binfmt_elf.c:2075
 do_coredump+0x1dfd/0x27b0 fs/coredump.c:950
 get_signal+0xd85/0xf70 kernel/signal.c:3019
 arch_do_signal_or_restart+0x96/0x480 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:330 [inline]
 irqentry_exit_to_user_mode+0x5e/0xa0 kernel/entry/common.c:184
 irqentry_exit+0x12/0x50 kernel/entry/common.c:287
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

read to 0xffff888237c25e68 of 1 bytes by task 3793 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:1339
 generic_shutdown_super+0xe3/0x210 fs/super.c:643
 kill_block_super+0x2a/0x70 fs/super.c:1753
 ext4_kill_sb+0x42/0x80 fs/ext4/super.c:7391
 deactivate_locked_super+0x75/0x1c0 fs/super.c:474
 deactivate_super+0x97/0xa0 fs/super.c:507
 cleanup_mnt+0x269/0x2e0 fs/namespace.c:1417
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1424
 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: 0x0f -> 0x10

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3793 Comm: syz-executor Not tainted 6.16.0-rc1-syzkaller-00005-g488ef3560196 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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