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ffmpeg
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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 <jamrial@gmail.com>
This commit is contained in:
James Almer 2019-04-25 19:04:01 -03:00
parent d7d82cfcd4
commit d88193c219
1 changed files with 21 additions and 13 deletions
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34
libavformat/aacdec.c
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@ -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;