==================================================================
BUG: KCSAN: data-race in __lru_add_drain_all / folios_put_refs

write to 0xffff888237d2a928 of 1 bytes by task 31243 on cpu 1:
 folio_batch_reinit include/linux/pagevec.h:50 [inline]
 folios_put_refs+0x26d/0x2b0 mm/swap.c:988
 folios_put include/linux/mm.h:1548 [inline]
 folio_batch_move_lru+0x202/0x230 mm/swap.c:175
 __folio_batch_add_and_move mm/swap.c:196 [inline]
 folio_add_lru+0x145/0x1f0 mm/swap.c:505
 shmem_alloc_and_add_folio mm/shmem.c:1961 [inline]
 shmem_get_folio_gfp+0x7d6/0xd90 mm/shmem.c:2522
 shmem_fault+0xfa/0x250 mm/shmem.c:2723
 __do_fault+0xb6/0x200 mm/memory.c:4988
 do_read_fault mm/memory.c:5403 [inline]
 do_fault mm/memory.c:5537 [inline]
 do_pte_missing mm/memory.c:4058 [inline]
 handle_pte_fault mm/memory.c:5900 [inline]
 __handle_mm_fault mm/memory.c:6043 [inline]
 handle_mm_fault+0xe98/0x2ac0 mm/memory.c:6212
 faultin_page mm/gup.c:1196 [inline]
 __get_user_pages+0xf6a/0x2350 mm/gup.c:1491
 populate_vma_page_range mm/gup.c:1929 [inline]
 __mm_populate+0x25b/0x3b0 mm/gup.c:2032
 mm_populate include/linux/mm.h:3386 [inline]
 vm_mmap_pgoff+0x224/0x2d0 mm/util.c:580
 ksys_mmap_pgoff+0xd0/0x330 mm/mmap.c:607
 x64_sys_call+0x1940/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:10
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237d2a928 of 1 bytes by task 31246 on cpu 0:
 folio_batch_count include/linux/pagevec.h:56 [inline]
 cpu_needs_drain mm/swap.c:773 [inline]
 __lru_add_drain_all+0x136/0x3f0 mm/swap.c:867
 lru_cache_disable+0x1f/0x30 mm/swap.c:920
 do_mbind mm/mempolicy.c:1311 [inline]
 kernel_mbind mm/mempolicy.c:1537 [inline]
 __do_sys_mbind mm/mempolicy.c:1611 [inline]
 __se_sys_mbind+0x4d2/0x11c0 mm/mempolicy.c:1607
 __x64_sys_mbind+0x78/0x90 mm/mempolicy.c:1607
 x64_sys_call+0x2662/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:238
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x1b -> 0x00

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 31246 Comm: syz.2.8833 Not tainted 6.14.0-rc4-syzkaller-00242-g7a5668899f54 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================