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

read-write to 0xffff888237d26468 of 1 bytes by task 8620 on cpu 1:
 folio_batch_add include/linux/pagevec.h:77 [inline]
 __folio_batch_add_and_move mm/swap.c:194 [inline]
 folio_add_lru+0xa5/0x1f0 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_get_folio mm/shmem.c:2662 [inline]
 shmem_fallocate+0x5cd/0x890 mm/shmem.c:3778
 vfs_fallocate+0x3b6/0x400 fs/open.c:339
 ksys_fallocate fs/open.c:363 [inline]
 __do_sys_fallocate fs/open.c:368 [inline]
 __se_sys_fallocate fs/open.c:366 [inline]
 __x64_sys_fallocate+0x7a/0xd0 fs/open.c:366
 x64_sys_call+0x1cd4/0x3000 arch/x86/include/generated/asm/syscalls_64.h:286
 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 8630 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: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 8630 Comm: wÞ£ÿ Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
==================================================================
lo speed is unknown, defaulting to 1000
lo speed is unknown, defaulting to 1000
lo speed is unknown, defaulting to 1000
infiniband syz1: set active
infiniband syz1: added lo
RDS/IB: syz1: added
smc: adding ib device syz1 with port count 1
smc:    ib device syz1 port 1 has no pnetid
lo speed is unknown, defaulting to 1000
lo speed is unknown, defaulting to 1000
lo speed is unknown, defaulting to 1000
lo speed is unknown, defaulting to 1000
lo speed is unknown, defaulting to 1000