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BUG: KCSAN: data-race in folios_put_refs / need_mlock_drain

write to 0xffff888237c265d0 of 1 bytes by task 25390 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]
 mlock_folio_batch+0x32c0/0x32f0 mm/mlock.c:209
 mlock_folio+0x1bb/0x220 mm/mlock.c:259
 mlock_vma_folio mm/internal.h:1008 [inline]
 __folio_add_file_rmap mm/rmap.c:1625 [inline]
 folio_add_file_rmap_ptes+0x1a0/0x1b0 mm/rmap.c:1642
 set_pte_range+0x208/0x430 mm/memory.c:5256
 finish_fault+0x89c/0xa70 mm/memory.c:5382
 do_shared_fault mm/memory.c:5602 [inline]
 do_fault mm/memory.c:5656 [inline]
 do_pte_missing mm/memory.c:4160 [inline]
 handle_pte_fault mm/memory.c:5997 [inline]
 __handle_mm_fault mm/memory.c:6140 [inline]
 handle_mm_fault+0x1519/0x2e80 mm/memory.c:6309
 faultin_page mm/gup.c:1193 [inline]
 __get_user_pages+0xf4e/0x2340 mm/gup.c:1491
 __get_user_pages_locked mm/gup.c:1757 [inline]
 faultin_page_range+0x352/0x5d0 mm/gup.c:1981
 madvise_populate mm/madvise.c:965 [inline]
 madvise_do_behavior+0x10e/0x2530 mm/madvise.c:1693
 do_madvise mm/madvise.c:1782 [inline]
 __do_sys_madvise mm/madvise.c:1790 [inline]
 __se_sys_madvise mm/madvise.c:1788 [inline]
 __x64_sys_madvise+0xcb/0x100 mm/madvise.c:1788
 x64_sys_call+0x23b8/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:29
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237c265d0 of 1 bytes by task 25393 on cpu 1:
 folio_batch_count include/linux/pagevec.h:56 [inline]
 need_mlock_drain+0x30/0x50 mm/mlock.c:235
 cpu_needs_drain mm/swap.c:779 [inline]
 __lru_add_drain_all+0x22a/0x3f0 mm/swap.c:867
 lru_cache_disable+0x1f/0x30 mm/swap.c:920
 do_mbind mm/mempolicy.c:1342 [inline]
 kernel_mbind mm/mempolicy.c:1568 [inline]
 __do_sys_mbind mm/mempolicy.c:1642 [inline]
 __se_sys_mbind+0x4b9/0xfe0 mm/mempolicy.c:1638
 __x64_sys_mbind+0x78/0x90 mm/mempolicy.c:1638
 x64_sys_call+0x13be/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:238
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 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: 1 UID: 0 PID: 25393 Comm: syz.6.7789 Tainted: G        W           6.15.0-rc1-syzkaller-00246-g900241a5cc15 #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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