From e8716b7e4c600577f43bd8519dfb30b214830fde Mon Sep 17 00:00:00 2001 From: Andreas Rheinhardt Date: Mon, 31 Aug 2020 19:47:50 +0200 Subject: [PATCH] avcodec/magicyuv: Simplify check for invalid Huffman codes Reviewed-by: Paul B Mahol Signed-off-by: Andreas Rheinhardt --- libavcodec/magicyuv.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/libavcodec/magicyuv.c b/libavcodec/magicyuv.c index 5578374429..f2204f3401 100644 --- a/libavcodec/magicyuv.c +++ b/libavcodec/magicyuv.c @@ -459,11 +459,15 @@ static int build_huffman(AVCodecContext *avctx, GetBitContext *gbit, int max) int x = get_bits(gbit, 7); int l = get_bitsz(gbit, b * 8) + 1; - for (k = 0; k < l; k++) - if (j + k < max) - s->len[i][j + k] = x; + k = j + l; + if (k > max) { + av_log(avctx, AV_LOG_ERROR, "Invalid Huffman codes\n"); + return AVERROR_INVALIDDATA; + } + + for (; j < k; j++) + s->len[i][j] = x; - j += l; if (j == max) { j = 0; if (s->huff_build(&s->vlc[i], s->len[i])) { @@ -474,9 +478,6 @@ static int build_huffman(AVCodecContext *avctx, GetBitContext *gbit, int max) if (i == s->planes) { break; } - } else if (j > max) { - av_log(avctx, AV_LOG_ERROR, "Invalid Huffman codes\n"); - return AVERROR_INVALIDDATA; } }