From 267eb2ab7f87696e1a156ca9a5ff1b1628d170c1 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 16 Jun 2019 11:39:15 +0200 Subject: avcodec/apedec: Fix multiple integer overflows and undefined behaviorin filter_3800() Fixes: left shift of negative value -4 Fixes: signed integer overflow: -15091694 * 167 cannot be represented in type 'int' Fixes: signed integer overflow: 1898547155 + 453967445 cannot be represented in type 'int' Fixes: 15258/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_APE_fuzzer-5759095564402688 Fixes: signed integer overflow: 962196438 * 31 cannot be represented in type 'int' Fixes: 15364/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_APE_fuzzer-5718799845687296 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/apedec.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'libavcodec/apedec.c') diff --git a/libavcodec/apedec.c b/libavcodec/apedec.c index 7cf99a00b1..27425b17e6 100644 --- a/libavcodec/apedec.c +++ b/libavcodec/apedec.c @@ -859,9 +859,9 @@ static av_always_inline int filter_3800(APEPredictor *p, return predictionA; } d2 = p->buf[delayA]; - d1 = (p->buf[delayA] - p->buf[delayA - 1]) << 1; - d0 = p->buf[delayA] + ((p->buf[delayA - 2] - p->buf[delayA - 1]) << 3); - d3 = p->buf[delayB] * 2 - p->buf[delayB - 1]; + d1 = (p->buf[delayA] - p->buf[delayA - 1]) * 2U; + d0 = p->buf[delayA] + ((p->buf[delayA - 2] - p->buf[delayA - 1]) * 8U); + d3 = p->buf[delayB] * 2U - p->buf[delayB - 1]; d4 = p->buf[delayB]; predictionA = d0 * p->coeffsA[filter][0] + @@ -881,7 +881,7 @@ static av_always_inline int filter_3800(APEPredictor *p, p->coeffsB[filter][1] -= (((d4 >> 30) & 2) - 1) * sign; p->filterB[filter] = p->lastA[filter] + (predictionB >> shift); - p->filterA[filter] = p->filterB[filter] + ((p->filterA[filter] * 31) >> 5); + p->filterA[filter] = p->filterB[filter] + ((int)(p->filterA[filter] * 31U) >> 5); return p->filterA[filter]; } @@ -902,7 +902,7 @@ static void long_filter_high_3800(int32_t *buffer, int order, int shift, int len dotprod = 0; sign = APESIGN(buffer[i]); for (j = 0; j < order; j++) { - dotprod += delay[j] * coeffs[j]; + dotprod += delay[j] * (unsigned)coeffs[j]; coeffs[j] += ((delay[j] >> 31) | 1) * sign; } buffer[i] -= dotprod >> shift; -- cgit v1.2.3