| Message ID | 20180917193400.3276-2-michael@niedermayer.cc |
|---|---|
| State | New |
| Headers | show |
On 9/17/18, Michael Niedermayer <michael@niedermayer.cc> wrote: > Fixes: Timeout > Fixes: > 10182/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ZMBV_fuzzer-6245951174344704 > > Found-by: continuous fuzzing process > https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> > --- > libavcodec/zmbv.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > > diff --git a/libavcodec/zmbv.c b/libavcodec/zmbv.c > index 177993d0a6..0c2daf47c2 100644 > --- a/libavcodec/zmbv.c > +++ b/libavcodec/zmbv.c > @@ -409,6 +409,7 @@ static int decode_frame(AVCodecContext *avctx, void > *data, int *got_frame, AVPac > int zret = Z_OK; // Zlib return code > int len = buf_size; > int hi_ver, lo_ver, ret; > + int min_size; > > /* parse header */ > if (len < 1) > @@ -510,7 +511,11 @@ static int decode_frame(AVCodecContext *avctx, void > *data, int *got_frame, AVPac > memset(c->prev, 0, avctx->width * avctx->height * (c->bpp / 8)); > c->decode_intra= decode_intra; > } > - > + if (c->flags & ZMBV_KEYFRAME) { > + min_size = avctx->width * avctx->height * (c->bpp / 8); Do you have proof this is really minimal possible thing zlib can compress single frame? If not, Drop. It. > + } else { > + min_size = (c->bx * c->by * 2 + 3) & ~3; > + } > if (!c->decode_intra) { > av_log(avctx, AV_LOG_ERROR, "Error! Got no format or no > keyframe!\n"); > return AVERROR_INVALIDDATA; > @@ -539,6 +544,10 @@ static int decode_frame(AVCodecContext *avctx, void > *data, int *got_frame, AVPac > } > c->decomp_len = c->zstream.total_out; > } > + if (min_size > c->decomp_len) { > + av_log(avctx, AV_LOG_ERROR, "input too small\n"); > + return AVERROR_INVALIDDATA; > + } > if (c->flags & ZMBV_KEYFRAME) { > frame->key_frame = 1; > frame->pict_type = AV_PICTURE_TYPE_I; > -- > 2.18.0 > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel >
On Mon, Sep 17, 2018 at 09:34:00PM +0200, Michael Niedermayer wrote: > Fixes: Timeout > Fixes: 10182/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ZMBV_fuzzer-6245951174344704 > > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> > --- > libavcodec/zmbv.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) will submit a slightly different solution based on discussion with durandal on IRC [...]
diff --git a/libavcodec/zmbv.c b/libavcodec/zmbv.c index 177993d0a6..0c2daf47c2 100644 --- a/libavcodec/zmbv.c +++ b/libavcodec/zmbv.c @@ -409,6 +409,7 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPac int zret = Z_OK; // Zlib return code int len = buf_size; int hi_ver, lo_ver, ret; + int min_size; /* parse header */ if (len < 1) @@ -510,7 +511,11 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPac memset(c->prev, 0, avctx->width * avctx->height * (c->bpp / 8)); c->decode_intra= decode_intra; } - + if (c->flags & ZMBV_KEYFRAME) { + min_size = avctx->width * avctx->height * (c->bpp / 8); + } else { + min_size = (c->bx * c->by * 2 + 3) & ~3; + } if (!c->decode_intra) { av_log(avctx, AV_LOG_ERROR, "Error! Got no format or no keyframe!\n"); return AVERROR_INVALIDDATA; @@ -539,6 +544,10 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPac } c->decomp_len = c->zstream.total_out; } + if (min_size > c->decomp_len) { + av_log(avctx, AV_LOG_ERROR, "input too small\n"); + return AVERROR_INVALIDDATA; + } if (c->flags & ZMBV_KEYFRAME) { frame->key_frame = 1; frame->pict_type = AV_PICTURE_TYPE_I;
Fixes: Timeout Fixes: 10182/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ZMBV_fuzzer-6245951174344704 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> --- libavcodec/zmbv.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)