avcodec/mjpegdec: Fix integer overflow in DC dequantization

Fixes: runtime error: signed integer overflow: -65535 * 65312 cannot be represented in type 'int'
Fixes: 4900/clusterfuzz-testcase-minimized-5769019744321536

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 1bfc1aa004)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2018-01-24 03:28:49 +01:00
parent 193b6df357
commit c1f7b2b6e1

View File

@ -686,7 +686,7 @@ static int decode_block(MJpegDecodeContext *s, int16_t *block, int component,
av_log(s->avctx, AV_LOG_ERROR, "error dc\n");
return AVERROR_INVALIDDATA;
}
val = val * quant_matrix[0] + s->last_dc[component];
val = val * (unsigned)quant_matrix[0] + s->last_dc[component];
val = av_clip_int16(val);
s->last_dc[component] = val;
block[0] = val;