From 9326117bf63b04a466d9e787224e56ba8cdbb215 Mon Sep 17 00:00:00 2001 From: Steve Lhomme Date: Wed, 13 Feb 2019 13:20:45 +0100 Subject: [PATCH] avformat/matroskadec: Check parents remaining length This was found through the Hacker One program on VLC but is not a security issue in libavformat Signed-off-by: Michael Niedermayer --- libavformat/matroskadec.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c index d7881d9c1d..5aa8a105dc 100644 --- a/libavformat/matroskadec.c +++ b/libavformat/matroskadec.c @@ -1197,6 +1197,18 @@ static int ebml_parse_elem(MatroskaDemuxContext *matroska, length, max_lengths[syntax->type], syntax->type); return AVERROR_INVALIDDATA; } + if (matroska->num_levels > 0) { + MatroskaLevel *level = &matroska->levels[matroska->num_levels - 1]; + AVIOContext *pb = matroska->ctx->pb; + int64_t pos = avio_tell(pb); + if (level->length != (uint64_t) -1 && + (pos + length) > (level->start + level->length)) { + av_log(matroska->ctx, AV_LOG_ERROR, + "Invalid length 0x%"PRIx64" > 0x%"PRIx64" in parent\n", + length, level->start + level->length); + return AVERROR_INVALIDDATA; + } + } } switch (syntax->type) {