Author: sagamusix
Date: Wed May 1 15:52:51 2024
New Revision: 20693
URL: https://source.openmpt.org/browse/openmpt/?op=revision&rev=20693
Log:
[Imp] XM: Reject files with impossible pattern header.
[Imp] XM: Speed up decoding early if pattern data cannot be read, ignore patterns > MAX_PATTERNS for decoding.
Modified:
trunk/OpenMPT/soundlib/Load_xm.cpp
Modified: trunk/OpenMPT/soundlib/Load_xm.cpp
==============================================================================
--- trunk/OpenMPT/soundlib/Load_xm.cpp Tue Apr 30 18:55:49 2024 (r20692)
+++ trunk/OpenMPT/soundlib/Load_xm.cpp Wed May 1 15:52:51 2024 (r20693)
@@ -244,18 +244,16 @@
for(PATTERNINDEX pat = 0; pat < fileHeader.patterns; pat++)
{
FileReader::pos_type curPos = file.GetPosition();
- uint32 headerSize = file.ReadUint32LE();
- file.Skip(1); // Pack method (= 0)
-
- ROWINDEX numRows = 64;
+ const uint32 headerSize = file.ReadUint32LE();
+ if(headerSize < 8 || !file.CanRead(headerSize - 4))
+ break;
+ file.Skip(1); // Pack method (= 0)
+ ROWINDEX numRows;
if(fileHeader.version == 0x0102)
- {
numRows = file.ReadUint8() + 1;
- } else
- {
+ else
numRows = file.ReadUint16LE();
- }
// A packed size of 0 indicates a completely empty pattern.
const uint16 packedSize = file.ReadUint16LE();
@@ -268,10 +266,8 @@
file.Seek(curPos + headerSize);
FileReader patternChunk = file.ReadChunk(packedSize);
- if(!sndFile.Patterns.Insert(pat, numRows) || packedSize == 0)
- {
+ if(pat >= MAX_PATTERNS || !sndFile.Patterns.Insert(pat, numRows) || packedSize == 0)
continue;
- }
enum PatternFlags
{
@@ -287,6 +283,9 @@
for(auto &m : sndFile.Patterns[pat])
{
+ if(!file.CanRead(1))
+ break;
+
uint8 info = patternChunk.ReadUint8();
uint8 vol = 0, command = 0;
@@ -1223,7 +1222,7 @@
if(!p->IsEmpty())
emptyPattern = false;
- // Apparently, completely empty patterns are loaded as empty 64-row patterns in FT2, regardless of their original size.
+ // Completely empty patterns are loaded as empty 64-row patterns in FT2, regardless of their original size.
// We have to avoid this, so we add a "break to row 0" command in the last row.
if(j == 1 && emptyPattern && numRows != 64)
{
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