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avcodec/apedec: Make coeffsA/B uint32_t, this avoids several cases of undefined behavior

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Changing the type to an unsigned one to avoid many casts was suggested
This may be inadequate for fixing the UB on ILP64

Fixes: signed integer overflow: -1418162611 * 383 cannot be represented in type 'int'
Fixes: 15547/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_APE_fuzzer-5691384901664768

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2019-07-02 12:30:32 +02:00
parent bf778af149
commit 1aad8937f7
1 changed files with 3 additions and 3 deletions
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6
libavcodec/apedec.c
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@ -125,8 +125,8 @@ typedef struct APEPredictor {
int32_t filterA[2];
int32_t filterB[2];
int32_t coeffsA[2][4]; ///< adaption coefficients
int32_t coeffsB[2][5]; ///< adaption coefficients
uint32_t coeffsA[2][4]; ///< adaption coefficients
uint32_t coeffsB[2][5]; ///< adaption coefficients
int32_t historybuffer[HISTORY_SIZE + PREDICTOR_SIZE];
unsigned int sample_pos;
@ -829,7 +829,7 @@ static av_always_inline int filter_fast_3320(APEPredictor *p,
}
predictionA = p->buf[delayA] * 2 - p->buf[delayA - 1];
p->lastA[filter] = decoded + (predictionA * p->coeffsA[filter][0] >> 9);
p->lastA[filter] = decoded + ((int32_t)(predictionA * p->coeffsA[filter][0]) >> 9);
if ((decoded ^ predictionA) > 0)
p->coeffsA[filter][0]++;