Fix potential underflow in MachoView::ParseSymbolTable string bounds check

The existing guard compared sym.n_strx against symtab.strsize, but the
string list buffer is filled by Read() which may return fewer bytes than
requested on a truncated file.  When the buffer is shorter than strsize,
an n_strx value that passes the strsize check can still exceed the actual
buffer length, causing the strnlen length argument to underflow and read
past the end of the buffer.  Replacing the check with a comparison against
stringList.GetLength() ensures the subtraction always stays in bounds.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: Weitao-Sun

view/macho/machoview.cpp

@@ -3382,7 +3382,10 @@ void MachoView::ParseSymbolTable(BinaryReader& reader, MachOHeader& header, cons
 			sym.n_value = (m_addressSize == 4) ? reader.Read32() : reader.Read64();
 			if (sym.n_value)
 				sym.n_value += m_imageBaseAdjustment;
-			if (sym.n_strx >= symtab.strsize || ((sym.n_type & N_TYPE) == N_INDR))
+			// Use GetLength() rather than symtab.strsize because Read() may return
+			// fewer bytes than requested; checking strsize would allow n_strx to pass
+			// while still being past the end of the actual buffer.
+			if (sym.n_strx >= header.stringList.GetLength() || ((sym.n_type & N_TYPE) == N_INDR))
 				continue;
 
 			const char* symbolName = (const char*)header.stringList.GetDataAt(sym.n_strx);