diff options
Diffstat (limited to 'user/audiofile/CVE-2017-6839.patch')
| -rw-r--r-- | user/audiofile/CVE-2017-6839.patch | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/user/audiofile/CVE-2017-6839.patch b/user/audiofile/CVE-2017-6839.patch new file mode 100644 index 000000000..ff0cdc2b3 --- /dev/null +++ b/user/audiofile/CVE-2017-6839.patch @@ -0,0 +1,120 @@ +From beacc44eb8cdf6d58717ec1a5103c5141f1b37f9 Mon Sep 17 00:00:00 2001 +From: Antonio Larrosa <larrosa@kde.org> +Date: Mon, 6 Mar 2017 13:43:53 +0100 +Subject: [PATCH 2/3] Check for multiplication overflow in MSADPCM decodeSample + +Check for multiplication overflow (using __builtin_mul_overflow +if available) in MSADPCM.cpp decodeSample and return an empty +decoded block if an error occurs. + +This fixes the 00193-audiofile-signintoverflow-MSADPCM case of #41 +--- + libaudiofile/modules/BlockCodec.cpp | 5 +-- + libaudiofile/modules/MSADPCM.cpp | 47 ++++++++++++++++++++++++++--- + 2 files changed, 46 insertions(+), 6 deletions(-) + +diff --git a/libaudiofile/modules/BlockCodec.cpp b/libaudiofile/modules/BlockCodec.cpp +index 45925e8..4731be1 100644 +--- a/libaudiofile/modules/BlockCodec.cpp ++++ b/libaudiofile/modules/BlockCodec.cpp +@@ -52,8 +52,9 @@ void BlockCodec::runPull() + // Decompress into m_outChunk. + for (int i=0; i<blocksRead; i++) + { +- decodeBlock(static_cast<const uint8_t *>(m_inChunk->buffer) + i * m_bytesPerPacket, +- static_cast<int16_t *>(m_outChunk->buffer) + i * m_framesPerPacket * m_track->f.channelCount); ++ if (decodeBlock(static_cast<const uint8_t *>(m_inChunk->buffer) + i * m_bytesPerPacket, ++ static_cast<int16_t *>(m_outChunk->buffer) + i * m_framesPerPacket * m_track->f.channelCount)==0) ++ break; + + framesRead += m_framesPerPacket; + } +diff --git a/libaudiofile/modules/MSADPCM.cpp b/libaudiofile/modules/MSADPCM.cpp +index 8ea3c85..ef9c38c 100644 +--- a/libaudiofile/modules/MSADPCM.cpp ++++ b/libaudiofile/modules/MSADPCM.cpp +@@ -101,24 +101,60 @@ static const int16_t adaptationTable[] = + 768, 614, 512, 409, 307, 230, 230, 230 + }; + ++int firstBitSet(int x) ++{ ++ int position=0; ++ while (x!=0) ++ { ++ x>>=1; ++ ++position; ++ } ++ return position; ++} ++ ++#ifndef __has_builtin ++#define __has_builtin(x) 0 ++#endif ++ ++int multiplyCheckOverflow(int a, int b, int *result) ++{ ++#if (defined __GNUC__ && __GNUC__ >= 5) || ( __clang__ && __has_builtin(__builtin_mul_overflow)) ++ return __builtin_mul_overflow(a, b, result); ++#else ++ if (firstBitSet(a)+firstBitSet(b)>31) // int is signed, so we can't use 32 bits ++ return true; ++ *result = a * b; ++ return false; ++#endif ++} ++ ++ + // Compute a linear PCM value from the given differential coded value. + static int16_t decodeSample(ms_adpcm_state &state, +- uint8_t code, const int16_t *coefficient) ++ uint8_t code, const int16_t *coefficient, bool *ok=NULL) + { + int linearSample = (state.sample1 * coefficient[0] + + state.sample2 * coefficient[1]) >> 8; ++ int delta; + + linearSample += ((code & 0x08) ? (code - 0x10) : code) * state.delta; + + linearSample = clamp(linearSample, MIN_INT16, MAX_INT16); + +- int delta = (state.delta * adaptationTable[code]) >> 8; ++ if (multiplyCheckOverflow(state.delta, adaptationTable[code], &delta)) ++ { ++ if (ok) *ok=false; ++ _af_error(AF_BAD_COMPRESSION, "Error decoding sample"); ++ return 0; ++ } ++ delta >>= 8; + if (delta < 16) + delta = 16; + + state.delta = delta; + state.sample2 = state.sample1; + state.sample1 = linearSample; ++ if (ok) *ok=true; + + return static_cast<int16_t>(linearSample); + } +@@ -212,13 +248,16 @@ int MSADPCM::decodeBlock(const uint8_t *encoded, int16_t *decoded) + { + uint8_t code; + int16_t newSample; ++ bool ok; + + code = *encoded >> 4; +- newSample = decodeSample(*state[0], code, coefficient[0]); ++ newSample = decodeSample(*state[0], code, coefficient[0], &ok); ++ if (!ok) return 0; + *decoded++ = newSample; + + code = *encoded & 0x0f; +- newSample = decodeSample(*state[1], code, coefficient[1]); ++ newSample = decodeSample(*state[1], code, coefficient[1], &ok); ++ if (!ok) return 0; + *decoded++ = newSample; + + encoded++; +-- +2.36.1 + |