| Message ID | 20200910231959.15573-1-michael@niedermayer.cc |
|---|---|
| State | Accepted |
| Commit | bad8b17a3da219777341acafd3e3113ea2477484 |
| Headers | show |
| Series | [FFmpeg-devel] avcodec/mobiclip: Check quantizer before table setup | expand |
| Context | Check | Description |
|---|---|---|
| andriy/default | pending | |
| andriy/make | success | Make finished |
| andriy/make_fate | success | Make fate finished |
On Fri, Sep 11, 2020 at 01:19:59AM +0200, Michael Niedermayer wrote: > Fixes: index -1 out of bounds for type 'const uint8_t [6][16]' > Fixes: out of array read > Fixes: shift exponent -21 is negative > Fixes: 25422/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MOBICLIP_fuzzer-5748258226569216 > Fixes: shift exponent 8039082 is too large for 32-bit type 'int' > Fixes: 25430/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MOBICLIP_fuzzer-5698567770210304 > > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> > --- > libavcodec/mobiclip.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/libavcodec/mobiclip.c b/libavcodec/mobiclip.c > index d147eddbae..13f0edc89d 100644 > --- a/libavcodec/mobiclip.c > +++ b/libavcodec/mobiclip.c > @@ -1323,6 +1323,10 @@ static int mobiclip_decode(AVCodecContext *avctx, void *data, > } > } else { > MotionXY *motion = s->motion; > + int quantizer = s->quantizer + get_se_golomb(gb); > + > + if (quantizer < 12 || quantizer > 161) From where this numbers come? I think this is too aggressive. > + return AVERROR_INVALIDDATA; > > memset(motion, 0, s->motion_size); > > @@ -1330,7 +1334,7 @@ static int mobiclip_decode(AVCodecContext *avctx, void *data, > frame->key_frame = 0; > s->dct_tab_idx = 0; > > - setup_qtables(avctx, s->quantizer + get_se_golomb(gb)); > + setup_qtables(avctx, quantizer); > for (int y = 0; y < avctx->height; y += 16) { > for (int x = 0; x < avctx->width; x += 16) { > int idx; > -- > 2.17.1 > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
On Fri, Sep 11, 2020 at 11:12:33AM +0200, Paul B Mahol wrote: > On Fri, Sep 11, 2020 at 01:19:59AM +0200, Michael Niedermayer wrote: > > Fixes: index -1 out of bounds for type 'const uint8_t [6][16]' > > Fixes: out of array read > > Fixes: shift exponent -21 is negative > > Fixes: 25422/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MOBICLIP_fuzzer-5748258226569216 > > Fixes: shift exponent 8039082 is too large for 32-bit type 'int' > > Fixes: 25430/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MOBICLIP_fuzzer-5698567770210304 > > > > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg > > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> > > --- > > libavcodec/mobiclip.c | 6 +++++- > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > diff --git a/libavcodec/mobiclip.c b/libavcodec/mobiclip.c > > index d147eddbae..13f0edc89d 100644 > > --- a/libavcodec/mobiclip.c > > +++ b/libavcodec/mobiclip.c > > @@ -1323,6 +1323,10 @@ static int mobiclip_decode(AVCodecContext *avctx, void *data, > > } > > } else { > > MotionXY *motion = s->motion; > > + int quantizer = s->quantizer + get_se_golomb(gb); > > + > > + if (quantizer < 12 || quantizer > 161) > > From where this numbers come? It comes from the implementation qtab is int and will overflow beyond 161 and below 12 the shift will be negative here: s->qtab[1][i] = quant8x8_tab[qx][i] << (qy - 2); > I think this is too aggressive. [...]
On Fri, Sep 11, 2020 at 08:09:48PM +0200, Michael Niedermayer wrote: > On Fri, Sep 11, 2020 at 11:12:33AM +0200, Paul B Mahol wrote: > > On Fri, Sep 11, 2020 at 01:19:59AM +0200, Michael Niedermayer wrote: > > > Fixes: index -1 out of bounds for type 'const uint8_t [6][16]' > > > Fixes: out of array read > > > Fixes: shift exponent -21 is negative > > > Fixes: 25422/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MOBICLIP_fuzzer-5748258226569216 > > > Fixes: shift exponent 8039082 is too large for 32-bit type 'int' > > > Fixes: 25430/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MOBICLIP_fuzzer-5698567770210304 > > > > > > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg > > > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> > > > --- > > > libavcodec/mobiclip.c | 6 +++++- > > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > > > diff --git a/libavcodec/mobiclip.c b/libavcodec/mobiclip.c > > > index d147eddbae..13f0edc89d 100644 > > > --- a/libavcodec/mobiclip.c > > > +++ b/libavcodec/mobiclip.c > > > @@ -1323,6 +1323,10 @@ static int mobiclip_decode(AVCodecContext *avctx, void *data, > > > } > > > } else { > > > MotionXY *motion = s->motion; > > > + int quantizer = s->quantizer + get_se_golomb(gb); > > > + > > > + if (quantizer < 12 || quantizer > 161) > > > > From where this numbers come? > > It comes from the implementation > qtab is int and will overflow beyond 161 ok then. > > and below 12 the shift will be negative here: > s->qtab[1][i] = quant8x8_tab[qx][i] << (qy - 2); > > > > I think this is too aggressive. > > > [...] > -- > Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB > > Many that live deserve death. And some that die deserve life. Can you give > it to them? Then do not be too eager to deal out death in judgement. For > even the very wise cannot see all ends. -- Gandalf > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
On Fri, Sep 11, 2020 at 10:00:02PM +0200, Paul B Mahol wrote: > On Fri, Sep 11, 2020 at 08:09:48PM +0200, Michael Niedermayer wrote: > > On Fri, Sep 11, 2020 at 11:12:33AM +0200, Paul B Mahol wrote: > > > On Fri, Sep 11, 2020 at 01:19:59AM +0200, Michael Niedermayer wrote: > > > > Fixes: index -1 out of bounds for type 'const uint8_t [6][16]' > > > > Fixes: out of array read > > > > Fixes: shift exponent -21 is negative > > > > Fixes: 25422/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MOBICLIP_fuzzer-5748258226569216 > > > > Fixes: shift exponent 8039082 is too large for 32-bit type 'int' > > > > Fixes: 25430/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MOBICLIP_fuzzer-5698567770210304 > > > > > > > > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg > > > > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> > > > > --- > > > > libavcodec/mobiclip.c | 6 +++++- > > > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/libavcodec/mobiclip.c b/libavcodec/mobiclip.c > > > > index d147eddbae..13f0edc89d 100644 > > > > --- a/libavcodec/mobiclip.c > > > > +++ b/libavcodec/mobiclip.c > > > > @@ -1323,6 +1323,10 @@ static int mobiclip_decode(AVCodecContext *avctx, void *data, > > > > } > > > > } else { > > > > MotionXY *motion = s->motion; > > > > + int quantizer = s->quantizer + get_se_golomb(gb); > > > > + > > > > + if (quantizer < 12 || quantizer > 161) > > > > > > From where this numbers come? > > > > It comes from the implementation > > qtab is int and will overflow beyond 161 > > ok then. will apply thx [...]
diff --git a/libavcodec/mobiclip.c b/libavcodec/mobiclip.c index d147eddbae..13f0edc89d 100644 --- a/libavcodec/mobiclip.c +++ b/libavcodec/mobiclip.c @@ -1323,6 +1323,10 @@ static int mobiclip_decode(AVCodecContext *avctx, void *data, } } else { MotionXY *motion = s->motion; + int quantizer = s->quantizer + get_se_golomb(gb); + + if (quantizer < 12 || quantizer > 161) + return AVERROR_INVALIDDATA; memset(motion, 0, s->motion_size); @@ -1330,7 +1334,7 @@ static int mobiclip_decode(AVCodecContext *avctx, void *data, frame->key_frame = 0; s->dct_tab_idx = 0; - setup_qtables(avctx, s->quantizer + get_se_golomb(gb)); + setup_qtables(avctx, quantizer); for (int y = 0; y < avctx->height; y += 16) { for (int x = 0; x < avctx->width; x += 16) { int idx;
Fixes: index -1 out of bounds for type 'const uint8_t [6][16]' Fixes: out of array read Fixes: shift exponent -21 is negative Fixes: 25422/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MOBICLIP_fuzzer-5748258226569216 Fixes: shift exponent 8039082 is too large for 32-bit type 'int' Fixes: 25430/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MOBICLIP_fuzzer-5698567770210304 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> --- libavcodec/mobiclip.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)