EXT4-fs error (device loop5): ext4_validate_block_bitmap:441: comm syz.5.1375: bg 0: block 35: padding at end of block bitmap is not set
EXT4-fs (loop5): Remounting filesystem read-only
EXT4-fs (loop5): 1 truncate cleaned up
SELinux: (dev loop5, type ext4) getxattr errno 5
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BUG: KCSAN: data-race in mlock_new_folio / need_mlock_drain

read-write to 0xffff888237c2b4a8 of 1 bytes by task 8019 on cpu 0:
 folio_batch_add include/linux/pagevec.h:77 [inline]
 mlock_new_folio+0x114/0x200 mm/mlock.c:280
 folio_add_lru_vma+0x5d/0x60 mm/swap.c:522
 do_anonymous_page mm/memory.c:4937 [inline]
 do_pte_missing mm/memory.c:4056 [inline]
 handle_pte_fault mm/memory.c:5900 [inline]
 __handle_mm_fault mm/memory.c:6043 [inline]
 handle_mm_fault+0x24d8/0x2ac0 mm/memory.c:6212
 faultin_page mm/gup.c:1196 [inline]
 __get_user_pages+0xf6a/0x2350 mm/gup.c:1491
 populate_vma_page_range mm/gup.c:1929 [inline]
 __mm_populate+0x25b/0x3b0 mm/gup.c:2032
 mm_populate include/linux/mm.h:3386 [inline]
 __do_sys_mremap mm/mremap.c:1243 [inline]
 __se_sys_mremap+0x89f/0xf10 mm/mremap.c:1045
 __x64_sys_mremap+0x67/0x80 mm/mremap.c:1045
 x64_sys_call+0x27e8/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:26
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237c2b4a8 of 1 bytes by task 8024 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: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+0x571/0x810 fs/ext4/super.c:1356
 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:7368
 deactivate_locked_super+0x7d/0x1c0 fs/super.c:473
 fc_drop_locked+0x50/0x60 fs/fs_context.c:379
 vfs_get_tree+0x160/0x1e0 fs/super.c:1841
 do_new_mount+0x227/0x690 fs/namespace.c:3560
 path_mount+0x49b/0xb30 fs/namespace.c:3887
 do_mount fs/namespace.c:3900 [inline]
 __do_sys_mount fs/namespace.c:4111 [inline]
 __se_sys_mount+0x27f/0x2d0 fs/namespace.c:4088
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4088
 x64_sys_call+0x2c84/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x19 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 8024 Comm: syz.5.1375 Not tainted 6.14.0-rc4-syzkaller-00073-g5394eea10651 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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