| Previous | Next |
| STATUS_INVALID_LDT_SIZE | STATUS_INVALID_LDT_DESCRIPTOR |
STATUS_INVALID_LDT_OFFSET
The update starts between descriptor entries instead of on a selector boundary
STATUS_INVALID_LDT_OFFSET means the starting value for LDT information is not an integral multiple of the selector size. This is an alignment error in descriptor-table coordinates. It differs from STATUS_INVALID_LDT_SIZE, which concerns the amount or growth of the table, and from STATUS_INVALID_LDT_DESCRIPTOR, which concerns the contents of an entry.
Microsoft documents LDT_ENTRY as the descriptor information associated with a selector and provides selector-inspection routines for x86/compatibility scenarios. A partial-descriptor starting offset would make subsequent bytes ambiguous: the receiver could not safely determine which descriptor fields the first byte belongs to. That is why a byte buffer that is large enough can still fail at its starting offset.
Record the raw offset before any pointer arithmetic, the expected descriptor/selector unit, and the number of entries being updated. Look for structure packing assumptions, accidental use of a byte offset where a selector index was expected, or truncation during 32/64-bit conversion in tooling around a 32-bit target. Do not realign the offset in the receiver and continue; silently moving the start changes which selector entries are modified. The producer must calculate the correct descriptor boundary.
What to inspect
- Preserve the exact caller-supplied offset and identify whether it is bytes, selectors, or an index.
- Check multiplication and conversion code that maps a selector/index to a descriptor-table byte offset.
- Reject rather than round a misaligned offset, because rounding changes the target descriptors.
References
- Microsoft: LDT_ENTRY
- Microsoft: GetThreadSelectorEntry
- Microsoft: Wow64GetThreadSelectorEntry
- Microsoft: NTVDM and 16-bit app support
- Microsoft Open Specifications: NTSTATUS values
Looking for a different code? Search another status or error code.