ffmpeg | branch: release/4.2 | Andreas Rheinhardt <andreas.rheinha...@gmail.com> | Thu Oct 10 11:47:41 2019 +0200| [eae4b6142223d6f214b97c00bc498884f3b98065] | committer: Andreas Rheinhardt
avcodec/zmbvenc: Correct offset in buffer zmbvenc allocates a buffer for a picture with padding on all four sides: The stride is choosen so large that it already contains padding on the right; the height also includes padding rows. The padding on the right of each row is also reused as padding for the left of the next row. So one still needs to add padding on the left for the first row. This is done by offsetting the actual pointer used to access the picture from the pointer returned by av_mallocz and the formula for this offset was wrong, because it ignored that a pixel can take more than one byte when calculating the offset resulting from the left padding of the first row. This fixes accesses outside of the allocated buffer that were reported in tickets #7980 and #7994. No writes were ever attempted outside of the buffer. Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@gmail.com> Reviewed-by: Tomas Härdin <tjop...@acc.umu.se> Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> (cherry picked from commit def04022f4a7058f99e669bfd978d431d79aec18) > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=eae4b6142223d6f214b97c00bc498884f3b98065 --- libavcodec/zmbvenc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libavcodec/zmbvenc.c b/libavcodec/zmbvenc.c index 48871758e0..4d3429393e 100644 --- a/libavcodec/zmbvenc.c +++ b/libavcodec/zmbvenc.c @@ -409,7 +409,7 @@ static av_cold int encode_init(AVCodecContext *avctx) */ c->pstride = FFALIGN((avctx->width + c->lrange) * c->bypp, 16); prev_size = FFALIGN(c->lrange * c->bypp, 16) + c->pstride * (c->lrange + avctx->height + c->urange); - prev_offset = FFALIGN(c->lrange, 16) + c->pstride * c->lrange; + prev_offset = FFALIGN(c->lrange * c->bypp, 16) + c->pstride * c->lrange; if (!(c->prev_buf = av_mallocz(prev_size))) { av_log(avctx, AV_LOG_ERROR, "Can't allocate picture.\n"); return AVERROR(ENOMEM); _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog To unsubscribe, visit link above, or email ffmpeg-cvslog-requ...@ffmpeg.org with subject "unsubscribe".
