[OMPT-svn-commit] OpenMPT r21055 - trunk/OpenMPT/soundlib

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

Author: sagamusix
Date: Sun Jun 23 14:05:01 2024
New Revision: 21055
URL: https://source.openmpt.org/browse/openmpt/?op=revision&rev=21055

Log:
[Fix] FTM: Avoid integer overflow in pattern+row calculation, eventually leading to addressing a negative pattern row (found with afl++).

Modified:
   trunk/OpenMPT/soundlib/Load_ftm.cpp

Modified: trunk/OpenMPT/soundlib/Load_ftm.cpp
==============================================================================
--- trunk/OpenMPT/soundlib/Load_ftm.cpp	Sun Jun 23 11:35:43 2024	(r21054)
+++ trunk/OpenMPT/soundlib/Load_ftm.cpp	Sun Jun 23 14:05:01 2024	(r21055)
@@ -383,9 +383,9 @@
 				}
 
 				const auto position = std::div(globalRow + spacing, fileHeader.rowsPerMeasure);
-				PATTERNINDEX pat = static_cast<PATTERNINDEX>(position.quot);
-				if(pat >= Patterns.GetNumPatterns())
+				if(position.quot >= fileHeader.numMeasures)
 					break;
+				const PATTERNINDEX pat = static_cast<PATTERNINDEX>(position.quot);
 
 				ModCommand &m = *Patterns[pat].GetpModCommand(position.rem, chn);
 				const uint8 param = ((data[0] & 0x0F) << 2) | (data[1] >> 6);  // 0...63