| Message ID | 20211203171956.12231-2-michael@niedermayer.cc |
|---|---|
| State | New |
| Headers | show |
| Series | [FFmpeg-devel,1/4] avformat/mov: Disallow duplicate smdm | expand |
| Context | Check | Description |
|---|---|---|
| andriy/make_x86 | success | Make finished |
| andriy/make_fate_x86 | success | Make fate finished |
| andriy/make_ppc | success | Make finished |
| andriy/make_fate_ppc | success | Make fate finished |
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 <michael@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?
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 <michael@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 ? thx [...]
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 <michael@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.
On Mon, Dec 06, 2021 at 03:50:34PM +0100, Anton Khirnov wrote: > 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 <michael@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. ok will change it to uint32 thx [...]
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;
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 <michael@niedermayer.cc> --- libavcodec/apedec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)