svq1dec: check that the reference frame has the same dimensions as the current one

They can be different if the last keyframe failed to decode correctly.
Fixes possible invalid reads in such a case.

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable@libav.org
This commit is contained in:
Anton Khirnov 2013-04-08 22:12:12 +02:00
parent c0771a1ac6
commit b1bb8fb860

View File

@ -689,7 +689,8 @@ static int svq1_decode_frame(AVCodecContext *avctx, void *data,
} else {
/* delta frame */
uint8_t *previous = s->prev->data[i];
if (!previous) {
if (!previous ||
s->prev->width != s->width || s->prev->height != s->height) {
av_log(avctx, AV_LOG_ERROR, "Missing reference frame.\n");
result = AVERROR_INVALIDDATA;
goto err;