From: Robert Luberda <robert@debian.org>
Date: Sun, 28 Jan 2018 23:47:40 +0100
Subject: CVE-2018-5996
Hopefully fix Memory Corruptions via RAR PPMd (CVE-2018-5996) by
applying a few changes from 7Zip 18.00-beta.
Bug-Debian: https://bugs.debian.org/#888314
---
CPP/7zip/Compress/Rar1Decoder.cpp | 13 +++++++++----
CPP/7zip/Compress/Rar1Decoder.h | 1 +
CPP/7zip/Compress/Rar2Decoder.cpp | 10 +++++++++-
CPP/7zip/Compress/Rar2Decoder.h | 1 +
CPP/7zip/Compress/Rar3Decoder.cpp | 23 ++++++++++++++++++++---
CPP/7zip/Compress/Rar3Decoder.h | 2 ++
6 files changed, 42 insertions(+), 8 deletions(-)
diff --git a/CPP/7zip/Compress/Rar1Decoder.cpp b/CPP/7zip/Compress/Rar1Decoder.cpp
index 1aaedcc..68030c7 100644
--- a/CPP/7zip/Compress/Rar1Decoder.cpp
+++ b/CPP/7zip/Compress/Rar1Decoder.cpp
@@ -29,7 +29,7 @@ public:
};
*/
-CDecoder::CDecoder(): m_IsSolid(false) { }
+CDecoder::CDecoder(): m_IsSolid(false), _errorMode(false) { }
void CDecoder::InitStructures()
{
@@ -406,9 +406,14 @@ HRESULT CDecoder::CodeReal(ISequentialInStream *inStream, ISequentialOutStream *
InitData();
if (!m_IsSolid)
{
+ _errorMode = false;
InitStructures();
InitHuff();
}
+
+ if (_errorMode)
+ return S_FALSE;
+
if (m_UnpackSize > 0)
{
GetFlagsBuf();
@@ -477,9 +482,9 @@ STDMETHODIMP CDecoder::Code(ISequentialInStream *inStream, ISequentialOutStream
const UInt64 *inSize, const UInt64 *outSize, ICompressProgressInfo *progress)
{
try { return CodeReal(inStream, outStream, inSize, outSize, progress); }
- catch(const CInBufferException &e) { return e.ErrorCode; }
- catch(const CLzOutWindowException &e) { return e.ErrorCode; }
- catch(...) { return S_FALSE; }
+ catch(const CInBufferException &e) { _errorMode = true; return e.ErrorCode; }
+ catch(const CLzOutWindowException &e) { _errorMode = true; return e.ErrorCode; }
+ catch(...) { _errorMode = true; return S_FALSE; }
}
STDMETHODIMP CDecoder::SetDecoderProperties2(const Byte *data, UInt32 size)
diff --git a/CPP/7zip/Compress/Rar1Decoder.h b/CPP/7zip/Compress/Rar1Decoder.h
index 630f089..01b606b 100644
--- a/CPP/7zip/Compress/Rar1Decoder.h
+++ b/CPP/7zip/Compress/Rar1Decoder.h
@@ -39,6 +39,7 @@ public:
Int64 m_UnpackSize;
bool m_IsSolid;
+ bool _errorMode;
UInt32 ReadBits(int numBits);
HRESULT CopyBlock(UInt32 distance, UInt32 len);
diff --git a/CPP/7zip/Compress/Rar2Decoder.cpp b/CPP/7zip/Compress/Rar2Decoder.cpp
index b3f2b4b..0580c8d 100644
--- a/CPP/7zip/Compress/Rar2Decoder.cpp
+++ b/CPP/7zip/Compress/Rar2Decoder.cpp
@@ -80,7 +80,8 @@ static const UInt32 kHistorySize = 1 << 20;
static const UInt32 kWindowReservSize = (1 << 22) + 256;
CDecoder::CDecoder():
- m_IsSolid(false)
+ m_IsSolid(false),
+ m_TablesOK(false)
{
}
@@ -100,6 +101,8 @@ UInt32 CDecoder::ReadBits(unsigned numBits) { return m_InBitStream.ReadBits(numB
bool CDecoder::ReadTables(void)
{
+ m_TablesOK = false;
+
Byte levelLevels[kLevelTableSize];
Byte newLevels[kMaxTableSize];
m_AudioMode = (ReadBits(1) == 1);
@@ -170,6 +173,8 @@ bool CDecoder::ReadTables(void)
}
memcpy(m_LastLevels, newLevels, kMaxTableSize);
+ m_TablesOK = true;
+
return true;
}
@@ -344,6 +349,9 @@ HRESULT CDecoder::CodeReal(ISequentialInStream *inStream, ISequentialOutStream *
return S_FALSE;
}
+ if (!m_TablesOK)
+ return S_FALSE;
+
UInt64 startPos = m_OutWindowStream.GetProcessedSize();
while (pos < unPackSize)
{
diff --git a/CPP/7zip/Compress/Rar2Decoder.h b/CPP/7zip/Compress/Rar2Decoder.h
index 3a0535c..0e9005f 100644
--- a/CPP/7zip/Compress/Rar2Decoder.h
+++ b/CPP/7zip/Compress/Rar2Decoder.h
@@ -139,6 +139,7 @@ class CDecoder :
UInt64 m_PackSize;
bool m_IsSolid;
+ bool m_TablesOK;
void InitStructures();
UInt32 ReadBits(unsigned numBits);
diff --git a/CPP/7zip/Compress/Rar3Decoder.cpp b/CPP/7zip/Compress/Rar3Decoder.cpp
index 3bf2513..6cb8a6a 100644
--- a/CPP/7zip/Compress/Rar3Decoder.cpp
+++ b/CPP/7zip/Compress/Rar3Decoder.cpp
@@ -92,7 +92,8 @@ CDecoder::CDecoder():
_writtenFileSize(0),
_vmData(0),
_vmCode(0),
- m_IsSolid(false)
+ m_IsSolid(false),
+ _errorMode(false)
{
Ppmd7_Construct(&_ppmd);
}
@@ -545,6 +546,9 @@ HRESULT CDecoder::ReadTables(bool &keepDecompressing)
return InitPPM();
}
+ TablesRead = false;
+ TablesOK = false;
+
_lzMode = true;
PrevAlignBits = 0;
PrevAlignCount = 0;
@@ -606,6 +610,9 @@ HRESULT CDecoder::ReadTables(bool &keepDecompressing)
}
}
}
+ if (InputEofError())
+ return S_FALSE;
+
TablesRead = true;
// original code has check here:
@@ -623,6 +630,9 @@ HRESULT CDecoder::ReadTables(bool &keepDecompressing)
RIF(m_LenDecoder.Build(&newLevels[kMainTableSize + kDistTableSize + kAlignTableSize]));
memcpy(m_LastLevels, newLevels, kTablesSizesSum);
+
+ TablesOK = true;
+
return S_OK;
}
@@ -824,7 +834,12 @@ HRESULT CDecoder::CodeReal(ICompressProgressInfo *progress)
PpmEscChar = 2;
PpmError = true;
InitFilters();
+ _errorMode = false;
}
+
+ if (_errorMode)
+ return S_FALSE;
+
if (!m_IsSolid || !TablesRead)
{
bool keepDecompressing;
@@ -838,6 +853,8 @@ HRESULT CDecoder::CodeReal(ICompressProgressInfo *progress)
bool keepDecompressing;
if (_lzMode)
{
+ if (!TablesOK)
+ return S_FALSE;
RINOK(DecodeLZ(keepDecompressing))
}
else
@@ -901,8 +918,8 @@ STDMETHODIMP CDecoder::Code(ISequentialInStream *inStream, ISequentialOutStream
_unpackSize = outSize ? *outSize : (UInt64)(Int64)-1;
return CodeReal(progress);
}
- catch(const CInBufferException &e) { return e.ErrorCode; }
- catch(...) { return S_FALSE; }
+ catch(const CInBufferException &e) { _errorMode = true; return e.ErrorCode; }
+ catch(...) { _errorMode = true; return S_FALSE; }
// CNewException is possible here. But probably CNewException is caused
// by error in data stream.
}
diff --git a/CPP/7zip/Compress/Rar3Decoder.h b/CPP/7zip/Compress/Rar3Decoder.h
index c130cec..2f72d7d 100644
--- a/CPP/7zip/Compress/Rar3Decoder.h
+++ b/CPP/7zip/Compress/Rar3Decoder.h
@@ -192,6 +192,7 @@ class CDecoder:
UInt32 _lastFilter;
bool m_IsSolid;
+ bool _errorMode;
bool _lzMode;
bool _unsupportedFilter;
@@ -200,6 +201,7 @@ class CDecoder:
UInt32 PrevAlignCount;
bool TablesRead;
+ bool TablesOK;
CPpmd7 _ppmd;
int PpmEscChar;