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BUG: KCSAN: data-race in __lru_add_drain_all / folios_put_refs

write to 0xffff888237d26468 of 1 bytes by task 22841 on cpu 1:
 folio_batch_reinit include/linux/pagevec.h:50 [inline]
 folios_put_refs+0x285/0x2d0 mm/swap.c:996
 folios_put include/linux/mm.h:1671 [inline]
 folio_batch_move_lru+0x24b/0x280 mm/swap.c:179
 __folio_batch_add_and_move mm/swap.c:196 [inline]
 folio_add_lru+0x14a/0x1f0 mm/swap.c:511
 shmem_alloc_and_add_folio mm/shmem.c:1991 [inline]
 shmem_get_folio_gfp+0x7a5/0xd50 mm/shmem.c:2556
 shmem_fault+0xf6/0x250 mm/shmem.c:2757
 __do_fault+0xbc/0x200 mm/memory.c:5320
 do_read_fault mm/memory.c:5755 [inline]
 do_fault mm/memory.c:5889 [inline]
 do_pte_missing mm/memory.c:4401 [inline]
 handle_pte_fault mm/memory.c:6273 [inline]
 __handle_mm_fault mm/memory.c:6411 [inline]
 handle_mm_fault+0xfab/0x2c60 mm/memory.c:6580
 faultin_page mm/gup.c:1126 [inline]
 __get_user_pages+0x1024/0x1ed0 mm/gup.c:1428
 populate_vma_page_range mm/gup.c:1860 [inline]
 __mm_populate+0x243/0x3a0 mm/gup.c:1963
 mm_populate include/linux/mm.h:3701 [inline]
 vm_mmap_pgoff+0x232/0x2e0 mm/util.c:586
 ksys_mmap_pgoff+0xc2/0x310 mm/mmap.c:604
 x64_sys_call+0x16bb/0x3000 arch/x86/include/generated/asm/syscalls_64.h:10
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xca/0x2b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237d26468 of 1 bytes by task 22842 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_mbind mm/mempolicy.c:1526 [inline]
 kernel_mbind mm/mempolicy.c:1752 [inline]
 __do_sys_mbind mm/mempolicy.c:1826 [inline]
 __se_sys_mbind+0x496/0xac0 mm/mempolicy.c:1822
 __x64_sys_mbind+0x78/0x90 mm/mempolicy.c:1822
 x64_sys_call+0x2a2b/0x3000 arch/x86/include/generated/asm/syscalls_64.h:238
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xca/0x2b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x01 -> 0x00

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 22842 Comm: syz.6.3890 Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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