[FFmpeg-cvslog] avcodec/apedec: Fix various integer overflows
Michael Niedermayer
git at videolan.org
Sun Jul 21 15:06:12 EEST 2019
ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sun Jun 16 11:32:10 2019 +0200| [240bf0e5960fca424e43b7ab1048897fdecabf26] | committer: Michael Niedermayer
avcodec/apedec: Fix various integer overflows
Fixes: signed integer overflow: -538976267 * 31 cannot be represented in type 'int'
Fixes: left shift of 65312 by 16 places cannot be represented in type 'int'
Fixes: 15255/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_APE_fuzzer-5718831688843264
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 at niedermayer.cc>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=240bf0e5960fca424e43b7ab1048897fdecabf26
---
libavcodec/apedec.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/libavcodec/apedec.c b/libavcodec/apedec.c
index 63335f542c..7cf99a00b1 100644
--- a/libavcodec/apedec.c
+++ b/libavcodec/apedec.c
@@ -554,7 +554,7 @@ static inline int ape_decode_value_3990(APEContext *ctx, APERice *rice)
overflow = range_get_symbol(ctx, counts_3980, counts_diff_3980);
if (overflow == (MODEL_ELEMENTS - 1)) {
- overflow = range_decode_bits(ctx, 16) << 16;
+ overflow = (unsigned)range_decode_bits(ctx, 16) << 16;
overflow |= range_decode_bits(ctx, 16);
}
@@ -1130,7 +1130,7 @@ static av_always_inline int predictor_update_filter(APEPredictor *p,
p->buf[delayA - 3] * p->coeffsA[filter][3];
/* Apply a scaled first-order filter compression */
- p->buf[delayB] = p->filterA[filter ^ 1] - ((p->filterB[filter] * 31) >> 5);
+ p->buf[delayB] = p->filterA[filter ^ 1] - ((int)(p->filterB[filter] * 31U) >> 5);
p->buf[adaptB] = APESIGN(p->buf[delayB]);
p->buf[delayB - 1] = p->buf[delayB] - p->buf[delayB - 1];
p->buf[adaptB - 1] = APESIGN(p->buf[delayB - 1]);
@@ -1143,7 +1143,7 @@ static av_always_inline int predictor_update_filter(APEPredictor *p,
p->buf[delayB - 4] * p->coeffsB[filter][4];
p->lastA[filter] = decoded + ((int)((unsigned)predictionA + (predictionB >> 1)) >> 10);
- p->filterA[filter] = p->lastA[filter] + ((p->filterA[filter] * 31) >> 5);
+ p->filterA[filter] = p->lastA[filter] + ((int)(p->filterA[filter] * 31U) >> 5);
sign = APESIGN(decoded);
p->coeffsA[filter][0] += p->buf[adaptA ] * sign;
@@ -1229,7 +1229,7 @@ static void predictor_decode_mono_3950(APEContext *ctx, int count)
p->buf = p->historybuffer;
}
- p->filterA[0] = currentA + ((p->filterA[0] * 31) >> 5);
+ p->filterA[0] = currentA + ((int)(p->filterA[0] * 31U) >> 5);
*(decoded0++) = p->filterA[0];
}
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