EXT4-fs (loop2): unmounting filesystem 00000000-0000-0000-0000-000000000000.
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BUG: KCSAN: data-race in mlock_new_folio / need_mlock_drain

read-write to 0xffff888237d27010 of 1 bytes by task 21983 on cpu 1:
 folio_batch_add include/linux/pagevec.h:77 [inline]
 mlock_new_folio+0x143/0x240 mm/mlock.c:280
 folio_add_lru_vma+0x5f/0x70 mm/swap.c:528
 do_anonymous_page mm/memory.c:5269 [inline]
 do_pte_missing mm/memory.c:4399 [inline]
 handle_pte_fault mm/memory.c:6273 [inline]
 __handle_mm_fault mm/memory.c:6411 [inline]
 handle_mm_fault+0x2858/0x2c60 mm/memory.c:6580
 faultin_page mm/gup.c:1126 [inline]
 __get_user_pages+0x1024/0x1ed0 mm/gup.c:1428
 populate_vma_page_range mm/gup.c:1860 [inline]
 __mm_populate+0x243/0x3a0 mm/gup.c:1963
 mm_populate include/linux/mm.h:3701 [inline]
 do_mremap mm/mremap.c:1952 [inline]
 __do_sys_mremap mm/mremap.c:1997 [inline]
 __se_sys_mremap+0xad4/0xb30 mm/mremap.c:1965
 __x64_sys_mremap+0x67/0x80 mm/mremap.c:1965
 x64_sys_call+0x2944/0x3000 arch/x86/include/generated/asm/syscalls_64.h:26
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd8/0x2c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237d27010 of 1 bytes by task 19089 on cpu 0:
 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
 ext4_put_super+0x624/0x7d0 fs/ext4/super.c:1348
 generic_shutdown_super+0xe6/0x210 fs/super.c:643
 kill_block_super+0x2a/0x70 fs/super.c:1722
 ext4_kill_sb+0x42/0x80 fs/ext4/super.c:7444
 deactivate_locked_super+0x75/0x1c0 fs/super.c:474
 deactivate_super+0x97/0xa0 fs/super.c:507
 cleanup_mnt+0x2a9/0x320 fs/namespace.c:1318
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1325
 task_work_run+0x131/0x1a0 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
 exit_to_user_mode_loop+0x1fe/0x740 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x1ef/0x2c0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x12 -> 0x15

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 19089 Comm: syz-executor Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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