syzbot

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BUG: KCSAN: data-race in __lru_add_drain_all / folio_add_lru

read-write to 0xffff888237c26468 of 1 bytes by task 4991 on cpu 0:
 folio_batch_add include/linux/pagevec.h:77 [inline]
 __folio_batch_add_and_move mm/swap.c:194 [inline]
 folio_add_lru+0xa4/0x1e0 mm/swap.c:511
 folio_add_lru_vma+0x49/0x70 mm/swap.c:530
 wp_page_copy mm/memory.c:3790 [inline]
 do_wp_page+0x15be/0x2560 mm/memory.c:4183
 handle_pte_fault mm/memory.c:6292 [inline]
 __handle_mm_fault mm/memory.c:6414 [inline]
 handle_mm_fault+0x8c7/0x3030 mm/memory.c:6583
 do_user_addr_fault+0x3fd/0x1050 arch/x86/mm/fault.c:1387
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x62/0xa0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
 __put_user_nocheck_4+0x3/0x10 arch/x86/lib/putuser.S:97
 ____sys_recvmsg+0x1a1/0x280 net/socket.c:2825
 ___sys_recvmsg+0x11f/0x3b0 net/socket.c:2854
 do_recvmmsg+0x1ef/0x560 net/socket.c:2949
 __sys_recvmmsg net/socket.c:3023 [inline]
 __do_sys_recvmmsg net/socket.c:3046 [inline]
 __se_sys_recvmmsg net/socket.c:3039 [inline]
 __x64_sys_recvmmsg+0xe5/0x170 net/socket.c:3039
 x64_sys_call+0x2b75/0x3000 arch/x86/include/generated/asm/syscalls_64.h:300
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc0/0x2a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237c26468 of 1 bytes by task 5017 on cpu 1:
 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+0x491/0xb30 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+0xc0/0x2a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0e -> 0x00

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 5017 Comm: syz.4.544 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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