From d88193c2196cf5342424aaa7a44b046c71c2527a Mon Sep 17 00:00:00 2001 From: James Almer Date: Thu, 25 Apr 2019 19:04:01 -0300 Subject: [PATCH] avformat/aacdec: fix demuxing of small frames 10 bytes (id3v2 header amount of bytes) were being read before any checks were made on the bitstream. The result was that we were overreading into the next frame if the current one was 8 or 9 bytes long. Fixes tickets #7271 and #7869. Signed-off-by: James Almer --- libavformat/aacdec.c | 34 +++++++++++++++++++++------------- 1 file changed, 21 insertions(+), 13 deletions(-) diff --git a/libavformat/aacdec.c b/libavformat/aacdec.c index bd324a1420..8a5450880b 100644 --- a/libavformat/aacdec.c +++ b/libavformat/aacdec.c @@ -20,6 +20,7 @@ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ +#include "libavutil/avassert.h" #include "libavutil/intreadwrite.h" #include "avformat.h" #include "avio_internal.h" @@ -154,17 +155,8 @@ static int adts_aac_read_packet(AVFormatContext *s, AVPacket *pkt) { int ret, fsize; - // Parse all the ID3 headers between frames - while (1) { - ret = av_get_packet(s->pb, pkt, FFMAX(ID3v2_HEADER_SIZE, ADTS_HEADER_SIZE)); - if (ret >= ID3v2_HEADER_SIZE && ff_id3v2_match(pkt->data, ID3v2_DEFAULT_MAGIC)) { - if ((ret = handle_id3(s, pkt)) >= 0) { - continue; - } - } - break; - } - +retry: + ret = av_get_packet(s->pb, pkt, ADTS_HEADER_SIZE); if (ret < 0) return ret; @@ -174,8 +166,24 @@ static int adts_aac_read_packet(AVFormatContext *s, AVPacket *pkt) } if ((AV_RB16(pkt->data) >> 4) != 0xfff) { - av_packet_unref(pkt); - return AVERROR_INVALIDDATA; + // Parse all the ID3 headers between frames + int append = ID3v2_HEADER_SIZE - ADTS_HEADER_SIZE; + + av_assert2(append > 0); + ret = av_append_packet(s->pb, pkt, append); + if (ret != append) { + av_packet_unref(pkt); + return AVERROR(EIO); + } + if (!ff_id3v2_match(pkt->data, ID3v2_DEFAULT_MAGIC)) { + av_packet_unref(pkt); + return AVERROR_INVALIDDATA; + } + ret = handle_id3(s, pkt); + if (ret < 0) + return ret; + + goto retry; } fsize = (AV_RB32(pkt->data + 3) >> 13) & 0x1FFF; -- GitLab