[FFmpeg-cvslog] avcodec/dca_lbr: Fix off by 1 error in freq check

[Michael Niedermayer]

ffmpeg | branch: release/3.1 | Michael Niedermayer <michael at niedermayer.cc> | Thu Feb  2 15:23:31 2017 +0100| [c26c8bb23a51cf6392b3a825ca48b8bd4c87b582] | committer: Michael Niedermayer

avcodec/dca_lbr: Fix off by 1 error in freq check

Fixes out of array read
Fixes: 510/clusterfuzz-testcase-5737865715646464

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 61f70416f8542cc86c84ae6e0342ba10a35d7cba)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=c26c8bb23a51cf6392b3a825ca48b8bd4c87b582
---

 libavcodec/dca_lbr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/dca_lbr.c b/libavcodec/dca_lbr.c
index 342603c..56c5f40 100644
--- a/libavcodec/dca_lbr.c
+++ b/libavcodec/dca_lbr.c
@@ -310,7 +310,7 @@ static int parse_tonal(DCALbrDecoder *s, int group)
                 break;  // End of subframe
 
             freq += diff - 2;
-            if (freq >> (5 - group) > s->nsubbands * 4 - 5) {
+            if (freq >> (5 - group) > s->nsubbands * 4 - 6) {
                 av_log(s->avctx, AV_LOG_ERROR, "Invalid spectral line offset\n");
                 return -1;
             }