DEBIAN-CVE-2026-89611

In the Linux kernel, the following vulnerability has been resolved:  ntfs: validate non-resident attribute offsets  ntfsattrupdatemeta() shifts the attribute name when converting between non-sparse and sparse attributes. Converting to sparse also adds the compressedsize field before the name and mapping pairs, requiring eight additional bytes in the attribute record.  However, the validator does not check that nameoffset is within safe boundaries for these operations or that the additional space is available. A malicious MFT record could set nameoffset such that:  1. The name is positioned at the very end of a non-sparse attribute.    Converting to sparse would shift the name forward by 8 bytes,    writing beyond the attribute boundary.  2. The name overlaps with the mapping pairs, causing corruption during    conversion.  Add validation to ensure: - For named attributes, nameoffset is within valid bounds - Name does not extend beyond the attribute or overlap with mapping pairs - For non-sparse, non-compressed attributes, eight bytes are available   after mappingpairsoffset for the compressedsize field  The space check also covers unnamed attributes, for which name_offset = 0 is valid and no name range needs to be checked.