[OMPT-svn-commit] OpenMPT r20335 - trunk/OpenMPT/src/mpt/io_read

[<sv...@op...>]

Author: manx
Date: Fri Mar 15 12:39:15 2024
New Revision: 20335
URL: https://source.openmpt.org/browse/openmpt/?op=revision&rev=20335

Log:
[Fix] mpt/io_read/filedata_base_unseekable.hpp: Avoid memory denial-of-service when trying to read way more data than the actual file size from unseekable files.

Modified:
   trunk/OpenMPT/src/mpt/io_read/filedata_base_unseekable.hpp

Modified: trunk/OpenMPT/src/mpt/io_read/filedata_base_unseekable.hpp
==============================================================================
--- trunk/OpenMPT/src/mpt/io_read/filedata_base_unseekable.hpp	Fri Mar 15 11:44:54 2024	(r20334)
+++ trunk/OpenMPT/src/mpt/io_read/filedata_base_unseekable.hpp	Fri Mar 15 12:39:15 2024	(r20335)
@@ -86,15 +86,14 @@
 			return;
 		}
 		std::size_t alignedpos = mpt::saturate_align_up<std::size_t>(target, QUANTUM_SIZE);
-		std::size_t needcount = alignedpos - cachesize;
-		EnsureCacheBuffer(needcount);
-		std::size_t readcount = InternalReadUnseekable(mpt::span(&cache[cachesize], alignedpos - cachesize)).size();
-		cachesize += readcount;
-		if (!InternalEof()) {
-			// can read further
-			return;
+		while (!InternalEof() && (cachesize < alignedpos)) {
+			EnsureCacheBuffer(BUFFER_SIZE);
+			std::size_t readcount = InternalReadUnseekable(mpt::span(&cache[cachesize], BUFFER_SIZE)).size();
+			cachesize += readcount;
+		}
+		if (InternalEof()) {
+			streamFullyCached = true;
 		}
-		streamFullyCached = true;
 	}
 
 private: