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| author | Michael Niedermayer <michael@niedermayer.cc> | 2020-10-02 22:48:12 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2020-10-15 22:53:56 +0200 |
| commit | 92233a63444001477acb70f2afa43a05f10b5fd5 (patch) | |
| tree | f96d1180ca35ea44b886e952c8bf7a7e1c3e1f0a /libavcodec/mobiclip.c | |
| parent | b6b640c5448f4a53e49caf93ccd665346d7598ef (diff) | |
| download | ffmpeg-92233a63444001477acb70f2afa43a05f10b5fd5.tar.gz | |
avcodec/mobiclip: Check that Motion vectors are within the input frame
The MV checks did not consider the width and height of the block, also they
had some off by 1 errors. This resulted in undefined behavior and crashes.
This commit instead errors out on these
Fixes: out of array read
Fixes: 26080/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MOBICLIP_fuzzer-5758146355920896
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Diffstat (limited to 'libavcodec/mobiclip.c')
| -rw-r--r-- | libavcodec/mobiclip.c | 30 |
1 files changed, 6 insertions, 24 deletions
diff --git a/libavcodec/mobiclip.c b/libavcodec/mobiclip.c index 5645234e00..82ff39e958 100644 --- a/libavcodec/mobiclip.c +++ b/libavcodec/mobiclip.c @@ -1189,14 +1189,14 @@ static int predict_motion(AVCodecContext *avctx, dst_linesize = s->pic[s->current_pic]->linesize[i]; dst = s->pic[s->current_pic]->data[i] + offsetx + offsety * dst_linesize; + if (offsetx + (mv.x >> 1) < 0 || + offsety + (mv.y >> 1) < 0 || + offsetx + width + (mv.x + 1 >> 1) > fwidth || + offsety + height + (mv.y + 1 >> 1) > fheight) + return AVERROR_INVALIDDATA; + switch (method) { case 0: - if (offsety + (mv.y >> 1) < 0 || - offsety + (mv.y >> 1) >= fheight || - offsetx + (mv.x >> 1) < 0 || - offsetx + (mv.x >> 1) >= fwidth) - return AVERROR_INVALIDDATA; - src = s->pic[sidx]->data[i] + offsetx + (mv.x >> 1) + (offsety + (mv.y >> 1)) * src_linesize; for (int y = 0; y < height; y++) { @@ -1207,12 +1207,6 @@ static int predict_motion(AVCodecContext *avctx, } break; case 1: - if (offsety + (mv.y >> 1) < 0 || - offsety + (mv.y >> 1) >= fheight || - offsetx + (mv.x >> 1) < 0 || - offsetx + (mv.x >> 1) >= fwidth) - return AVERROR_INVALIDDATA; - src = s->pic[sidx]->data[i] + offsetx + (mv.x >> 1) + (offsety + (mv.y >> 1)) * src_linesize; for (int y = 0; y < height; y++) { @@ -1225,12 +1219,6 @@ static int predict_motion(AVCodecContext *avctx, } break; case 2: - if (offsety + (mv.y >> 1) < 0 || - offsety + (mv.y >> 1) >= fheight - 1 || - offsetx + (mv.x >> 1) < 0 || - offsetx + (mv.x >> 1) >= fwidth) - return AVERROR_INVALIDDATA; - src = s->pic[sidx]->data[i] + offsetx + (mv.x >> 1) + (offsety + (mv.y >> 1)) * src_linesize; for (int y = 0; y < height; y++) { @@ -1243,12 +1231,6 @@ static int predict_motion(AVCodecContext *avctx, } break; case 3: - if (offsety + (mv.y >> 1) < 0 || - offsety + (mv.y >> 1) >= fheight - 1 || - offsetx + (mv.x >> 1) < 0 || - offsetx + (mv.x >> 1) >= fwidth) - return AVERROR_INVALIDDATA; - src = s->pic[sidx]->data[i] + offsetx + (mv.x >> 1) + (offsety + (mv.y >> 1)) * src_linesize; for (int y = 0; y < height; y++) { |