From ca0a38f2f7803ab8fa12913d0385d4c70f8d6345 Mon Sep 17 00:00:00 2001 From: Andreas Rheinhardt Date: Tue, 28 Apr 2020 02:24:16 +0200 Subject: [PATCH] avformat/matroskaenc: Replace impossible condition with assert If a FLAC track uses an unconventional channel layout, the Matroska muxer adds a WAVEFORMATEXTENSIBLE_CHANNEL_MASK VorbisComment to the CodecPrivate to preserve this information. And given that FLAC uses 24bit length fields, the muxer checks if the length is more than this and errors out if it is. Yet this can never happen, because we create the AVDictionary that is the source for the VorbisComment. It only contains exactly one entry that can't grow infinitely large (in fact, the length of the VorbisComment is <= 4 + 33 + 1 + 18 + strlen(LIBAVFORMAT_IDENT)). So we can simply assert the size to be < (1 << 24) - 4. Signed-off-by: Andreas Rheinhardt --- libavformat/matroskaenc.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c index f69b3c39da..87dff6ab7d 100644 --- a/libavformat/matroskaenc.c +++ b/libavformat/matroskaenc.c @@ -631,10 +631,7 @@ static int put_flac_codecpriv(AVFormatContext *s, AVIOContext *pb, av_dict_set(&dict, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", buf, 0); len = ff_vorbiscomment_length(dict, vendor, NULL, 0); - if (len >= (1 << 24) - 4) { - av_dict_free(&dict); - return AVERROR(EINVAL); - } + av_assert1(len < (1 << 24) - 4); data = av_malloc(len + 4); if (!data) {