[FFmpeg-cvslog] Merge commit '74d98d1b0e0e7af444c933ea3c472494de3ce6f2'

[Clément Bœsch]

ffmpeg | branch: master | Clément Bœsch <clement at stupeflix.com> | Tue Jun 21 14:37:55 2016 +0200| [82439dec0fbf8a31159327ddf57096a0013109b9] | committer: Clément Bœsch

Merge commit '74d98d1b0e0e7af444c933ea3c472494de3ce6f2'

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

See e630ca5111077fa8adc972fe8a3d7e2b3e8dc91f

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 at stupeflix.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=82439dec0fbf8a31159327ddf57096a0013109b9
---

 libavformat/mpegts.c |   19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
index 6acb797..379ffbd 100644
--- a/libavformat/mpegts.c
+++ b/libavformat/mpegts.c
@@ -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;


======================================================================

diff --cc libavformat/mpegts.c
index 6acb797,740cc14..379ffbd
--- a/libavformat/mpegts.c
+++ b/libavformat/mpegts.c
@@@ -1406,6 -1151,6 +1406,14 @@@ static int parse_MP4SLDescrTag(MP4Descr
      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 -1163,9 +1426,9 @@@
          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;