rtpdec_mpeg4: Check the remaining amount of data before reading

This fixes possible buffer overreads.

Signed-off-by: Martin Storsjö <martin@martin.st>
This commit is contained in:
Martin Storsjö 2013-01-15 15:35:18 +02:00
parent 977d4a3b8a
commit a7ba324413

View File

@ -109,11 +109,14 @@ static int parse_fmtp_config(AVCodecContext *codec, char *value)
return 0; return 0;
} }
static int rtp_parse_mp4_au(PayloadContext *data, const uint8_t *buf) static int rtp_parse_mp4_au(PayloadContext *data, const uint8_t *buf, int len)
{ {
int au_headers_length, au_header_size, i; int au_headers_length, au_header_size, i;
GetBitContext getbitcontext; GetBitContext getbitcontext;
if (len < 2)
return AVERROR_INVALIDDATA;
/* decode the first 2 bytes where the AUHeader sections are stored /* decode the first 2 bytes where the AUHeader sections are stored
length in bits */ length in bits */
au_headers_length = AV_RB16(buf); au_headers_length = AV_RB16(buf);
@ -125,6 +128,10 @@ static int rtp_parse_mp4_au(PayloadContext *data, const uint8_t *buf)
/* skip AU headers length section (2 bytes) */ /* skip AU headers length section (2 bytes) */
buf += 2; buf += 2;
len -= 2;
if (len < data->au_headers_length_bytes)
return AVERROR_INVALIDDATA;
init_get_bits(&getbitcontext, buf, data->au_headers_length_bytes * 8); init_get_bits(&getbitcontext, buf, data->au_headers_length_bytes * 8);
@ -165,7 +172,7 @@ static int aac_parse_packet(AVFormatContext *ctx, PayloadContext *data,
int flags) int flags)
{ {
int ret; int ret;
if (rtp_parse_mp4_au(data, buf)) if (rtp_parse_mp4_au(data, buf, len))
return -1; return -1;
buf += data->au_headers_length_bytes + 2; buf += data->au_headers_length_bytes + 2;
@ -173,6 +180,8 @@ static int aac_parse_packet(AVFormatContext *ctx, PayloadContext *data,
/* XXX: Fixme we only handle the case where rtp_parse_mp4_au define /* XXX: Fixme we only handle the case where rtp_parse_mp4_au define
one au_header */ one au_header */
if (len < data->au_headers[0].size)
return AVERROR_INVALIDDATA;
if ((ret = av_new_packet(pkt, data->au_headers[0].size)) < 0) if ((ret = av_new_packet(pkt, data->au_headers[0].size)) < 0)
return ret; return ret;
memcpy(pkt->data, buf, data->au_headers[0].size); memcpy(pkt->data, buf, data->au_headers[0].size);