[FFmpeg-cvslog] avcodec/ituh263dec: Fix runtime error: left shift of 1342177279 by 1 places cannot be represented in type 'int'

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Thu Feb 23 23:46:30 2017 +0100| [0d85c7bb5a4c398863848ecdf44a0c9f1778da06] | committer: Michael Niedermayer

avcodec/ituh263dec: Fix runtime error: left shift of 1342177279 by 1 places cannot be represented in type 'int'

Fixes: 659/clusterfuzz-testcase-5866673603084288

Huge DMV could be created by an encoder ignoring the spec

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=0d85c7bb5a4c398863848ecdf44a0c9f1778da06
---

 libavcodec/ituh263dec.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libavcodec/ituh263dec.c b/libavcodec/ituh263dec.c
index 9a2c8e6..09b6a2f 100644
--- a/libavcodec/ituh263dec.c
+++ b/libavcodec/ituh263dec.c
@@ -303,6 +303,10 @@ static int h263p_decode_umotion(MpegEncContext * s, int pred)
    {
       code <<= 1;
       code += get_bits1(&s->gb);
+      if (code >= 32768) {
+          avpriv_request_sample(s->avctx, "Huge DMV");
+          return AVERROR_INVALIDDATA;
+      }
    }
    sign = code & 1;
    code >>= 1;