Re: [PATCH v3] ntfs: validate non-resident attribute offsets

[Hongling Zeng <zhongling0719@126.com>]

在 2026年08月06日 21:17, Namjae Jeon 写道:
>> +       /* Ensure there's room for the compressed_size field if needed. */
>> +       if (!(a->flags & ATTR_IS_SPARSE) &&
>> +           !(a->flags & ATTR_IS_COMPRESSED) &&
>> +           attr_len - mp_offset < sizeof(a->data.non_resident.compressed_size))
>> +               return false;
> Sorry for the confusion. I rechecked the code and realized that
> ATTR_COMPRESSION_MASK is correct here. It covers the entire
> compression field, while ATTR_IS_COMPRESSED checks only the 0x0001
> bit. Since this validation checks whether the attribute layout
> includes compressed_size, it should use the mask, consistent with the
> existing min_len check.  So I have applied the previously attached
> patch.
>
> Thanks!
You're absolutely correct， Thanks for the guidance and applied the 
patch . I now understand that ATTR_COMPRESSION_MASK
   (0x00ff) is the correct choice—it covers all compression cases, not 
just  the 0x0001 flag.