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BUG: KCSAN: data-race in mlock_folio / need_mlock_drain

read-write to 0xffff888237c27010 of 1 bytes by task 3923 on cpu 0:
 folio_batch_add include/linux/pagevec.h:77 [inline]
 mlock_folio+0x14d/0x240 mm/mlock.c:257
 mlock_vma_folio mm/internal.h:1043 [inline]
 __folio_add_file_rmap mm/rmap.c:1594 [inline]
 folio_add_file_rmap_ptes+0x1d0/0x1e0 mm/rmap.c:1611
 set_pte_range+0x2c1/0x4f0 mm/memory.c:5481
 finish_fault+0x937/0xad0 mm/memory.c:5619
 do_read_fault mm/memory.c:5759 [inline]
 do_fault mm/memory.c:5889 [inline]
 do_pte_missing mm/memory.c:4401 [inline]
 handle_pte_fault mm/memory.c:6273 [inline]
 __handle_mm_fault mm/memory.c:6411 [inline]
 handle_mm_fault+0x1201/0x3030 mm/memory.c:6580
 faultin_page mm/gup.c:1126 [inline]
 __get_user_pages+0x1023/0x1ea0 mm/gup.c:1428
 populate_vma_page_range mm/gup.c:1860 [inline]
 __mm_populate+0x242/0x390 mm/gup.c:1963
 mm_populate include/linux/mm.h:3701 [inline]
 vm_mmap_pgoff+0x23b/0x2d0 mm/util.c:586
 ksys_mmap_pgoff+0xc1/0x310 mm/mmap.c:604
 x64_sys_call+0x16bb/0x3000 arch/x86/include/generated/asm/syscalls_64.h:10
 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 0xffff888237c27010 of 1 bytes by task 3954 on cpu 1:
 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_add_drain_all+0x10/0x20 mm/swap.c:893
 invalidate_bdev+0x47/0x70 block/bdev.c:101
 bdev_disk_changed+0xeb/0xcb0 block/partitions/core.c:657
 loop_reread_partitions drivers/block/loop.c:448 [inline]
 loop_set_status+0x692/0x750 drivers/block/loop.c:1293
 loop_set_status64 drivers/block/loop.c:1393 [inline]
 lo_ioctl+0x672/0x13a0 drivers/block/loop.c:1579
 blkdev_ioctl+0x387/0x460 block/ioctl.c:792
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xce/0x140 fs/ioctl.c:583
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:583
 x64_sys_call+0x14b0/0x3000 arch/x86/include/generated/asm/syscalls_64.h:17
 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: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3954 Comm: syz.4.134 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
==================================================================
 loop4: p1 p3 p4
loop4: p4 size 589824 extends beyond EOD, truncated