[FFmpeg-cvslog] avcodec/cbs_jpeg_syntax_template: Check table index before use in dht()

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sun Apr 12 21:38:55 2020 +0200| [d31862c2b1b1fd07dcdc503193056d6c9ad28ccb] | committer: Michael Niedermayer

avcodec/cbs_jpeg_syntax_template: Check table index before use in dht()

Fixes: out of array access
Fixes: 21515/clusterfuzz-testcase-minimized-ffmpeg_BSF_TRACE_HEADERS_fuzzer-5766121576988672

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d31862c2b1b1fd07dcdc503193056d6c9ad28ccb
---

 libavcodec/cbs_jpeg_syntax_template.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavcodec/cbs_jpeg_syntax_template.c b/libavcodec/cbs_jpeg_syntax_template.c
index d3cd9ff62e..1ffb77d231 100644
--- a/libavcodec/cbs_jpeg_syntax_template.c
+++ b/libavcodec/cbs_jpeg_syntax_template.c
@@ -108,6 +108,9 @@ static int FUNC(dht)(CodedBitstreamContext *ctx, RWContext *rw,
 
     n = 2;
     for (i = 0; n < current->Lh; i++) {
+        if (i >= 8)
+            return AVERROR_INVALIDDATA;
+
         CHECK(FUNC(huffman_table)(ctx, rw, &current->table[i]));
 
         ++n;