The MobiClip decoder uses adjacent pixels for prediction; yet when
accessing the left pixel, it was forgotten to clip the x coordinate.
This results in an heap-buffer-overflow. It can e.g. be reproduced with
the sample from https://samples.ffmpeg.org/V-codecs/MOHD/crap.avi when
forcing the video decoder to mobiclip.
Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@gmail.com>
---
libavcodec/mobiclip.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libavcodec/mobiclip.c b/libavcodec/mobiclip.c
index 8758e7f617..47387fce90 100644
--- a/libavcodec/mobiclip.c
+++ b/libavcodec/mobiclip.c
@@ -905,7 +905,7 @@ static int predict_intra(AVCodecContext *avctx, AVFrame
*frame, int ax, int ay,
int arr1[16];
int arr2[16];
uint8_t *top = frame->data[plane] + FFMAX(ay - 1, 0) *
frame->linesize[plane] + ax;
- uint8_t *left = frame->data[plane] + ay * frame->linesize[plane] +
ax - 1;
+ uint8_t *left = frame->data[plane] + ay * frame->linesize[plane] +
FFMAX(ax - 1, 0);
int bottommost = frame->data[plane][(ay + size - 1) *
frame->linesize[plane] + FFMAX(ax - 1, 0)];
int rightmost = frame->data[plane][FFMAX(ay - 1, 0) *
frame->linesize[plane] + ax + size - 1];
int avg = (bottommost + rightmost + 1) / 2 + 2 * get_se_golomb(gb);
--
2.25.1
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