syzbot

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BUG: KCSAN: data-race in folios_put_refs / need_mlock_drain

write to 0xffff888237d27010 of 1 bytes by task 12483 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]
 mlock_folio_batch+0x1b5a/0x1b90 mm/mlock.c:209
 mlock_new_folio+0x1d6/0x240 mm/mlock.c:282
 folio_add_lru_vma+0x5f/0x70 mm/swap.c:528
 do_anonymous_page mm/memory.c:5269 [inline]
 do_pte_missing mm/memory.c:4399 [inline]
 handle_pte_fault mm/memory.c:6273 [inline]
 __handle_mm_fault mm/memory.c:6411 [inline]
 handle_mm_fault+0x2858/0x2c60 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
 do_mlock+0x471/0x520 mm/mlock.c:653
 __do_sys_mlock mm/mlock.c:661 [inline]
 __se_sys_mlock mm/mlock.c:659 [inline]
 __x64_sys_mlock+0x36/0x50 mm/mlock.c:659
 x64_sys_call+0x1794/0x3000 arch/x86/include/generated/asm/syscalls_64.h:150
 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 0xffff888237d27010 of 1 bytes by task 12484 on cpu 0:
 folio_batch_count include/linux/pagevec.h:56 [inline]
 need_mlock_drain+0x30/0x50 mm/mlock.c:235
 cpu_needs_drain mm/swap.c:786 [inline]
 __lru_add_drain_all+0x273/0x450 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+0x2b2/0x1360 mm/migrate.c:2601
 __x64_sys_move_pages+0x78/0x90 mm/migrate.c:2601
 x64_sys_call+0x27c3/0x3000 arch/x86/include/generated/asm/syscalls_64.h:280
 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: 12484 Comm: syz.3.2988 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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