[FFmpeg-cvslog] avcodec/cbs_h2645: Treat slices without data as invalid

[Andreas Rheinhardt]

ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at gmail.com> | Mon Dec  9 23:26:03 2019 +0100| [66fac1ff7ccbc4fb6a3aa6b9a95de7b6bc31d14e] | committer: Michael Niedermayer

avcodec/cbs_h2645: Treat slices without data as invalid

Slices that end after their header (meaning slices after the header
without any data before the rbsp_stop_one_bit or possibly without any
rbsp_stop_one_bit at all) are invalid and are now dropped. This ensures
that one doesn't run into two asserts in cbs_h2645_write_slice_data().

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
Fixes: 19629/clusterfuzz-testcase-minimized-ffmpeg_BSF_H264_METADATA_fuzzer-5676822528524288
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=66fac1ff7ccbc4fb6a3aa6b9a95de7b6bc31d14e
---

 libavcodec/cbs_h2645.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libavcodec/cbs_h2645.c b/libavcodec/cbs_h2645.c
index 19da58f8fc..7a4eecf439 100644
--- a/libavcodec/cbs_h2645.c
+++ b/libavcodec/cbs_h2645.c
@@ -861,6 +861,9 @@ static int cbs_h264_read_nal_unit(CodedBitstreamContext *ctx,
             if (err < 0)
                 return err;
 
+            if (!cbs_h2645_read_more_rbsp_data(&gbc))
+                return AVERROR_INVALIDDATA;
+
             pos = get_bits_count(&gbc);
             len = unit->data_size;
 
@@ -1036,6 +1039,9 @@ static int cbs_h265_read_nal_unit(CodedBitstreamContext *ctx,
             if (err < 0)
                 return err;
 
+            if (!cbs_h2645_read_more_rbsp_data(&gbc))
+                return AVERROR_INVALIDDATA;
+
             pos = get_bits_count(&gbc);
             len = unit->data_size;