Description
In the Linux kernel, the following vulnerability has been resolved:
ntfs: fix off-by-one in mapping pairs decoding bounds checks
In ntfs_mapping_pairs_decompress(), attr_end points one byte past the end of the attribute record:
attr_end = (u8 *)attr + le32_to_cpu(attr->length);
The two bounds checks validating that mapping pair data bytes fit within the attribute use strict greater-than (>), which allows a one-byte out-of-bounds read when the data extends exactly to attr_end:
b = *buf & 0xf; if (b) { if (unlikely(buf + b > attr_end)) // off-by-one goto io_error; for (deltaxcn = (s8)buf[b--]; b; b--) deltaxcn = (deltaxcn << 8) + buf[b]; }
When buf + b == attr_end, the check evaluates to false and buf[b] reads one byte past the valid attribute boundary. The same pattern appears in the LCN delta bytes check.
Fix both checks to use >= so that buf[b] at exactly attr_end is correctly rejected as out of bounds.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HAffected software
Source: the vendor's advisory (CNA). NVD analysis pending.
No affected versions have been published.
Timeline
- Published
- Aug 15, 2026
- Last modified
- Aug 19, 2026
- NVD status
- Received