syzbot

EXT4-fs (loop7): 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 0xffff888237d265d0 of 1 bytes by task 12591 on cpu 1:
 folio_batch_add include/linux/pagevec.h:77 [inline]
 mlock_new_folio+0x115/0x210 mm/mlock.c:280
 folio_add_lru_vma+0x5d/0x60 mm/swap.c:522
 do_anonymous_page mm/memory.c:5047 [inline]
 do_pte_missing mm/memory.c:4158 [inline]
 handle_pte_fault mm/memory.c:5997 [inline]
 __handle_mm_fault mm/memory.c:6140 [inline]
 handle_mm_fault+0x275f/0x2e80 mm/memory.c:6309
 faultin_page mm/gup.c:1193 [inline]
 __get_user_pages+0xf4e/0x2340 mm/gup.c:1491
 populate_vma_page_range mm/gup.c:1929 [inline]
 __mm_populate+0x25d/0x3c0 mm/gup.c:2032
 mm_populate include/linux/mm.h:3487 [inline]
 __do_sys_mlockall mm/mlock.c:771 [inline]
 __se_sys_mlockall+0x36d/0x3d0 mm/mlock.c:747
 __x64_sys_mlockall+0x1f/0x30 mm/mlock.c:747
 x64_sys_call+0x2801/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:152
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237d265d0 of 1 bytes by task 22798 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:779 [inline]
 __lru_add_drain_all+0x22a/0x3f0 mm/swap.c:867
 lru_add_drain_all+0x10/0x20 mm/swap.c:883
 invalidate_bdev+0x47/0x70 block/bdev.c:101
 ext4_put_super+0x65b/0x910 fs/ext4/super.c:1343
 generic_shutdown_super+0xe5/0x220 fs/super.c:642
 kill_block_super+0x2a/0x70 fs/super.c:1710
 ext4_kill_sb+0x44/0x80 fs/ext4/super.c:7393
 deactivate_locked_super+0x7d/0x1c0 fs/super.c:473
 deactivate_super+0x9f/0xb0 fs/super.c:506
 cleanup_mnt+0x26e/0x2e0 fs/namespace.c:1435
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1442
 task_work_run+0x13c/0x1b0 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xa8/0x120 kernel/entry/common.c:218
 do_syscall_64+0xd6/0x1a0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x11 -> 0x16

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 22798 Comm: syz-executor Not tainted 6.15.0-rc2-syzkaller-00488-g6fea5fabd332 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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