ntfs: validate non-resident attribute offsets

Summary

In the Linux kernel, the following vulnerability has been resolved: ntfs: validate non-resident attribute offsets ntfs_attr_update_meta() shifts the attribute name when converting between non-sparse and sparse attributes. Converting to sparse also adds the compressed_size field before the name and mapping pairs, requiring eight additional bytes in the attribute record. However, the validator does not check that name_offset is within safe boundaries for these operations or that the additional space is available. A malicious MFT record could set name_offset 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, name_offset 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 mapping_pairs_offset for the compressed_size field The space check also covers unnamed attributes, for which name_offset = 0 is valid and no name range needs to be checked.

Timeline

1. Sep 11, 2026, 7:45 PM UTCCVE published
2. Oct 19, 2026, 8:49 AM UTCRecord last updated

Affected versions

• Linux Linux

  From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in cd7b3dc7557faadeea626034e3bac68a449851ef; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in a83e82b0ec3ae523028e24813f23f18b43e8fc1c; fixed in 7.2.4

• Linux Linux

  Version range not reported

• KernelLinux

  fixed in 7.2.4

References 2