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Merge commit '74d98d1b0e0e7af444c933ea3c472494de3ce6f2'

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* commit '74d98d1b0e0e7af444c933ea3c472494de3ce6f2':
  mpegts: Validate the SL Packet Header Configuration

See e630ca5111

Our local timestamp_len > 64 is adjusted to > 63 to match the Libav
check and the actual specifications (14496-1, 10.2.2).

There is no need to request a sample as it violates the specifications
and such a file would likely be the result of a crafted/fuzzed sample.

On the other hand, the clipping of the value is kept for extra safety.

Merged-by: Clément Bœsch <clement@stupeflix.com>
This commit is contained in:
Clément Bœsch 2016-06-21 14:37:55 +02:00
commit 82439dec0f
1 changed files with 11 additions and 8 deletions
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19
libavformat/mpegts.c
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@ -1406,6 +1406,14 @@ static int parse_MP4SLDescrTag(MP4DescrParseContext *d, int64_t off, int len)
if (!descr)
return AVERROR_INVALIDDATA;
#define R8_CHECK_CLIP_MAX(dst, maxv) do { \
descr->sl.dst = avio_r8(&d->pb); \
if (descr->sl.dst > maxv) { \
descr->sl.dst = maxv; \
return AVERROR_INVALIDDATA; \
} \
} while (0)
predefined = avio_r8(&d->pb);
if (!predefined) {
int lengths;
@ -1418,14 +1426,9 @@ static int parse_MP4SLDescrTag(MP4DescrParseContext *d, int64_t off, int len)
descr->sl.use_idle = !!(flags & 0x02);
descr->sl.timestamp_res = avio_rb32(&d->pb);
avio_rb32(&d->pb);
descr->sl.timestamp_len = avio_r8(&d->pb);
if (descr->sl.timestamp_len > 64) {
avpriv_request_sample(NULL, "timestamp_len > 64");
descr->sl.timestamp_len = 64;
return AVERROR_PATCHWELCOME;
}
descr->sl.ocr_len = avio_r8(&d->pb);
descr->sl.au_len = avio_r8(&d->pb);
R8_CHECK_CLIP_MAX(timestamp_len, 63);
R8_CHECK_CLIP_MAX(ocr_len, 63);
R8_CHECK_CLIP_MAX(au_len, 31);
descr->sl.inst_bitrate_len = avio_r8(&d->pb);
lengths = avio_rb16(&d->pb);
descr->sl.degr_prior_len = lengths >> 12;