Quoting Michael Niedermayer (2021-12-06 12:01:09) > On Mon, Dec 06, 2021 at 11:23:12AM +0100, Anton Khirnov wrote: > > Quoting Michael Niedermayer (2021-12-03 18:19:54) > > > Fixes: Integer overflow > > > Fixes: > > > 40973/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_APE_fuzzer-6739312704618496 > > > > > > Found-by: continuous fuzzing process > > > https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg > > > Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> > > > --- > > > libavcodec/apedec.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/libavcodec/apedec.c b/libavcodec/apedec.c > > > index 9c723f29977..5c3261cf5cb 100644 > > > --- a/libavcodec/apedec.c > > > +++ b/libavcodec/apedec.c > > > @@ -1337,7 +1337,7 @@ static void do_apply_filter(APEContext *ctx, int > > > version, APEFilter *f, > > > absres = FFABSU(res); > > > if (absres) > > > *f->adaptcoeffs = APESIGN(res) * > > > - (8 << ((absres > f->avg * 3LL) + > > > (absres > (f->avg + f->avg / 3)))); > > > + (8 << ((absres > f->avg * 3LL) + > > > (absres > ((int64_t)f->avg + f->avg / 3)))); > > > /* equivalent to the following code > > > if (absres <= f->avg * 4 / 3) > > > *f->adaptcoeffs = APESIGN(res) * 8; > > > -- > > > 2.17.1 > > > > Does this not assume a 32bit int? > > hmm > you mean avg could overflow 64bit ? > iam not sure that can happen but > we could make avg int32 or uint32 ?
Seems it cannot, but it's not completely obvious. So changing it to uint32 might make sense, since it cannot be negative. -- Anton Khirnov _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
