Prevent out of array write. Similar to what Michael Niedermayer did to address the same issue.
Bug-Id: CVE-2014-2263 CC: [email protected] --- It reports the error while trying to write the pmt, but doesn't stop as Kieran suggested. For the master and 10 I'd provide one that optionally exists at write_header time. As long we do not support multiple services sdt (and pat) are fine. libavformat/mpegtsenc.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) diff --git a/libavformat/mpegtsenc.c b/libavformat/mpegtsenc.c index 86fc631..28ea1bd 100644 --- a/libavformat/mpegtsenc.c +++ b/libavformat/mpegtsenc.c @@ -254,7 +254,7 @@ static void mpegts_write_pmt(AVFormatContext *s, MpegTSService *service) { MpegTSWrite *ts = s->priv_data; uint8_t data[SECTION_LENGTH], *q, *desc_length_ptr, *program_info_length_ptr; - int val, stream_type, i; + int val, stream_type, i, err = 0; q = data; put16(&q, 0xe000 | service->pcr_pid); @@ -272,6 +272,11 @@ static void mpegts_write_pmt(AVFormatContext *s, MpegTSService *service) AVStream *st = s->streams[i]; MpegTSWriteStream *ts_st = st->priv_data; AVDictionaryEntry *lang = av_dict_get(st->metadata, "language", NULL,0); + + if (q - data > SECTION_LENGTH - 3 - 2 - 6) { + err = 1; + goto fail; + } switch(st->codec->codec_id) { case AV_CODEC_ID_MPEG1VIDEO: case AV_CODEC_ID_MPEG2VIDEO: @@ -321,6 +326,10 @@ static void mpegts_write_pmt(AVFormatContext *s, MpegTSService *service) *len_ptr = 0; for (p = lang->value; next && *len_ptr < 255 / 4 * 4; p = next + 1) { + if (q - data > SECTION_LENGTH - 4) { + err = 1; + goto fail; + } next = strchr(p, ','); if (strlen(p) != 3 && (!next || next != p + 3)) continue; /* not a 3-letter code */ @@ -355,6 +364,11 @@ static void mpegts_write_pmt(AVFormatContext *s, MpegTSService *service) *q++ = language[1]; *q++ = language[2]; *q++ = 0x10; /* normal subtitles (0x20 = if hearing pb) */ + + if (q - data > SECTION_LENGTH - 4) { + err = 1; + goto fail; + } if(st->codec->extradata_size == 4) { memcpy(q, st->codec->extradata, 4); q += 4; @@ -380,6 +394,15 @@ static void mpegts_write_pmt(AVFormatContext *s, MpegTSService *service) desc_length_ptr[0] = val >> 8; desc_length_ptr[1] = val; } + +fail: + if (err) + av_log(s, AV_LOG_ERROR, + "The pmt section cannot fit the stream %d and following.\n" + "Try reducing the number of languages in the audio streams " + "or the total number of streams.\n", + i); + mpegts_write_section1(&service->pmt, PMT_TID, service->sid, 0, 0, 0, data, q - data); } -- 1.9.0 _______________________________________________ libav-devel mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-devel
