EXT4-fs error (device loop2): ext4_validate_block_bitmap:441: comm syz.2.746: bg 0: block 345: padding at end of block bitmap is not set
EXT4-fs (loop2): Remounting filesystem read-only
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BUG: KCSAN: data-race in __lru_add_drain_all / folio_add_lru

read-write to 0xffff888237c25ee8 of 1 bytes by task 5961 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+0xa5/0x1f0 mm/swap.c:511
 shmem_alloc_and_add_folio mm/shmem.c:1972 [inline]
 shmem_get_folio_gfp+0x7ab/0xd60 mm/shmem.c:2536
 shmem_fault+0xf6/0x250 mm/shmem.c:2737
 __do_fault+0xbc/0x200 mm/memory.c:5281
 do_read_fault mm/memory.c:5716 [inline]
 do_fault mm/memory.c:5850 [inline]
 do_pte_missing mm/memory.c:4362 [inline]
 handle_pte_fault mm/memory.c:6195 [inline]
 __handle_mm_fault mm/memory.c:6336 [inline]
 handle_mm_fault+0xf78/0x2be0 mm/memory.c:6505
 faultin_page mm/gup.c:1126 [inline]
 __get_user_pages+0x102a/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:3471 [inline]
 vm_mmap_pgoff+0x232/0x2e0 mm/util.c:586
 ksys_mmap_pgoff+0xc2/0x310 mm/mmap.c:604
 x64_sys_call+0x14a3/0x3000 arch/x86/include/generated/asm/syscalls_64.h:10
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237c25ee8 of 1 bytes by task 5980 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_add_drain_all+0x10/0x20 mm/swap.c:893
 generic_fadvise+0x40b/0x430 mm/fadvise.c:167
 vfs_fadvise mm/fadvise.c:185 [inline]
 ksys_fadvise64_64 mm/fadvise.c:198 [inline]
 __do_sys_fadvise64 mm/fadvise.c:210 [inline]
 __se_sys_fadvise64 mm/fadvise.c:208 [inline]
 __x64_sys_fadvise64+0xcb/0x110 mm/fadvise.c:208
 x64_sys_call+0x29c5/0x3000 arch/x86/include/generated/asm/syscalls_64.h:222
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x1b -> 0x1c

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 5980 Comm: syz.2.746 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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