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BUG: KCSAN: data-race in __lru_add_drain_all / folio_add_lru

read-write to 0xffff888237d26668 of 1 bytes by task 10151 on cpu 1:
 folio_batch_add include/linux/pagevec.h:77 [inline]
 __folio_batch_add_and_move mm/swap.c:194 [inline]
 folio_add_lru+0xa4/0x1e0 mm/swap.c:511
 shmem_alloc_and_add_folio mm/shmem.c:2031 [inline]
 shmem_get_folio_gfp+0x7b0/0xd60 mm/shmem.c:2567
 shmem_get_folio mm/shmem.c:2673 [inline]
 shmem_write_begin+0xfc/0x1f0 mm/shmem.c:3327
 generic_perform_write+0x183/0x490 mm/filemap.c:4319
 shmem_file_write_iter+0xc5/0xf0 mm/shmem.c:3502
 __kernel_write_iter+0x319/0x590 fs/read_write.c:621
 __kernel_write+0x99/0xc0 fs/read_write.c:641
 __dump_emit fs/coredump.c:1221 [inline]
 dump_emit+0x5ff/0x720 fs/coredump.c:1259
 elf_core_dump+0x1a66/0x2330 fs/binfmt_elf.c:2062
 coredump_write+0xacc/0xdd0 fs/coredump.c:1050
 do_coredump fs/coredump.c:1127 [inline]
 vfs_coredump+0x26c7/0x3130 fs/coredump.c:1201
 get_signal+0xd80/0xf60 kernel/signal.c:3019
 arch_do_signal_or_restart+0x96/0x450 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:98 [inline]
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline]
 irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline]
 irqentry_exit+0xf7/0x520 kernel/entry/common.c:219
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618

read to 0xffff888237d26668 of 1 bytes by task 10149 on cpu 0:
 folio_batch_count include/linux/pagevec.h:56 [inline]
 cpu_needs_drain mm/swap.c:780 [inline]
 __lru_add_drain_all+0x17e/0x450 mm/swap.c:877
 lru_cache_disable+0x1f/0x30 mm/swap.c:930
 do_pages_move mm/migrate.c:2343 [inline]
 kernel_move_pages mm/migrate.c:2592 [inline]
 __do_sys_move_pages mm/migrate.c:2606 [inline]
 __se_sys_move_pages+0x2c0/0x1420 mm/migrate.c:2601
 __x64_sys_move_pages+0x78/0x90 mm/migrate.c:2601
 x64_sys_call+0x1d35/0x3020 arch/x86/include/generated/asm/syscalls_64.h:280
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x03 -> 0x00

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 10149 Comm: syz.7.1850 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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