[FFmpeg-cvslog] avcodec/shorten: Check k in get_uint()

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sat May  6 18:28:09 2017 +0200| [7b6a51f59c467ab9f4b73122dc269206fb517425] | committer: Michael Niedermayer

avcodec/shorten: Check k in get_uint()

Fixes: undefined shift
Fixes: 1371/clusterfuzz-testcase-minimized-5770822591447040

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=7b6a51f59c467ab9f4b73122dc269206fb517425
---

 libavcodec/shorten.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libavcodec/shorten.c b/libavcodec/shorten.c
index 90569bdb1f..2d3540a229 100644
--- a/libavcodec/shorten.c
+++ b/libavcodec/shorten.c
@@ -160,8 +160,11 @@ static int allocate_buffers(ShortenContext *s)
 
 static inline unsigned int get_uint(ShortenContext *s, int k)
 {
-    if (s->version != 0)
+    if (s->version != 0) {
         k = get_ur_golomb_shorten(&s->gb, ULONGSIZE);
+        if (k > 31U)
+            return AVERROR_INVALIDDATA;
+    }
     return get_ur_golomb_shorten(&s->gb, k);
 }