http://bugs.winehq.org/show_bug.cgi?id=27439
--- Comment #7 from Henri Verbeet hverbeet@gmail.com 2011-11-01 14:40:41 CDT --- (In reply to comment #6)
The reason ... maybe HeapAlloc failed (its result isn't checked in this code)?
Considering it fails on read access, it's probably more likely that either buffer->resource.allocatedMemory is invalid or start / end are wrong.