==================================================================
BUG: KCSAN: data-race in lru_add_drain_all / lru_cache_add

write to 0xffff888237d26468 of 1 bytes by task 13569 on cpu 1:
 pagevec_add include/linux/pagevec.h:74 [inline]
 lru_cache_add+0x74/0x130 mm/swap.c:461
 shmem_getpage_gfp+0xcf8/0x1410 mm/shmem.c:1934
 shmem_fault+0x16d/0x500 mm/shmem.c:2116
 __do_fault mm/memory.c:3637 [inline]
 do_read_fault mm/memory.c:3939 [inline]
 do_fault mm/memory.c:4067 [inline]
 handle_pte_fault mm/memory.c:4318 [inline]
 __handle_mm_fault mm/memory.c:4453 [inline]
 handle_mm_fault+0xe8d/0x1a70 mm/memory.c:4551
 faultin_page mm/gup.c:850 [inline]
 __get_user_pages+0x947/0xee0 mm/gup.c:1069
 populate_vma_page_range mm/gup.c:1402 [inline]
 __mm_populate+0x24d/0x380 mm/gup.c:1450
 mm_populate include/linux/mm.h:2582 [inline]
 vm_mmap_pgoff+0x145/0x1d0 mm/util.c:524
 ksys_mmap_pgoff+0xe1/0x380 mm/mmap.c:1632
 do_syscall_64+0x34/0x50 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888237d26468 of 1 bytes by task 13567 on cpu 0:
 pagevec_count include/linux/pagevec.h:61 [inline]
 lru_add_drain_all+0x108/0x3c0 mm/swap.c:813
 migrate_prep mm/migrate.c:73 [inline]
 do_pages_move mm/migrate.c:1772 [inline]
 kernel_move_pages+0x2c5/0xb30 mm/migrate.c:1988
 __do_sys_move_pages mm/migrate.c:2002 [inline]
 __se_sys_move_pages mm/migrate.c:1997 [inline]
 __x64_sys_move_pages+0x74/0x90 mm/migrate.c:1997
 do_syscall_64+0x34/0x50 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 13567 Comm: syz-executor.4 Not tainted 5.12.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================