From 85737a4d76f8a39ec5554abe62bcbc41b6123d09 Mon Sep 17 00:00:00 2001 From: Andreas Rheinhardt Date: Wed, 23 Sep 2020 05:42:31 +0200 Subject: avcodec/magicyuv: Improve overread check when parsing Huffman tables Reviewed-by: Paul B Mahol Signed-off-by: Andreas Rheinhardt --- libavcodec/magicyuv.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'libavcodec') diff --git a/libavcodec/magicyuv.c b/libavcodec/magicyuv.c index b56d3e9d32..d2f6a9b01e 100644 --- a/libavcodec/magicyuv.c +++ b/libavcodec/magicyuv.c @@ -394,8 +394,13 @@ static int build_huffman(AVCodecContext *avctx, GetBitContext *gbit, int max) while (get_bits_left(gbit) >= 8) { int b = get_bits(gbit, 1); int x = get_bits(gbit, 7); - int l = get_bitsz(gbit, b * 8) + 1; + int l = 1; + if (b) { + if (get_bits_left(gbit) < 8) + break; + l += get_bits(gbit, 8); + } k = j + l; if (k > max || x == 0 || x > 32) { av_log(avctx, AV_LOG_ERROR, "Invalid Huffman codes\n"); -- cgit v1.2.3