Browsing an embedded .baml resource runs it through BamlReader.ReadDocument,
whose post-parse defer pass walks the record list with NavigateTree. That walk
recursed on every nested StaticResourceStart/KeyElementStart record with no
depth cap and indexed the record list with no bound. A crafted resource could
therefore drive recursion into a StackOverflowException -- which is uncatchable
and kills the process despite the resource node's try/catch -- or walk the index
off the end of the list. Both are reachable from ordinary resource browsing, no
project export required.
Consolidate the duplicated defer walk into one bounded, depth-capped helper that
fails with a catchable InvalidDataException, so the existing UI catch turns a
malformed resource into a "BAML decompilation failed" message instead of a crash.
Reject an oversized signature length before it drives a multi-gigabyte allocation
(it is read before the MSBAML check), and resolve defer offsets with TryGetValue
so a bogus offset reports malformed data rather than escaping as a bare
KeyNotFoundException.
Assisted-by: Claude:claude-opus-4-8:Claude Code