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BUG: KCSAN: data-race in __lru_add_drain_all / folio_add_lru

read-write to 0xffff888237c25ea8 of 1 bytes by task 4475 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:510
 shmem_alloc_and_add_folio mm/shmem.c:2006 [inline]
 shmem_get_folio_gfp+0x7ab/0xd60 mm/shmem.c:2597
 shmem_get_folio mm/shmem.c:2703 [inline]
 shmem_write_begin+0xa8/0x190 mm/shmem.c:3353
 generic_perform_write+0x181/0x490 mm/filemap.c:4175
 shmem_file_write_iter+0xc5/0xf0 mm/shmem.c:3528
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x52a/0x960 fs/read_write.c:686
 ksys_pwrite64 fs/read_write.c:793 [inline]
 __do_sys_pwrite64 fs/read_write.c:801 [inline]
 __se_sys_pwrite64 fs/read_write.c:798 [inline]
 __x64_sys_pwrite64+0xfd/0x150 fs/read_write.c:798
 x64_sys_call+0xc4d/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:19
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237c25ea8 of 1 bytes by task 4492 on cpu 1:
 folio_batch_count include/linux/pagevec.h:56 [inline]
 cpu_needs_drain mm/swap.c:778 [inline]
 __lru_add_drain_all+0x12b/0x3f0 mm/swap.c:872
 lru_cache_disable+0x1f/0x30 mm/swap.c:925
 do_mbind mm/mempolicy.c:1456 [inline]
 kernel_mbind mm/mempolicy.c:1682 [inline]
 __do_sys_mbind mm/mempolicy.c:1756 [inline]
 __se_sys_mbind+0x496/0xac0 mm/mempolicy.c:1752
 __x64_sys_mbind+0x78/0x90 mm/mempolicy.c:1752
 x64_sys_call+0x2932/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:238
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 4492 Comm: syz.1.307 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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