[FFmpeg-cvslog] avcodec/dxv: Correct integer overflow in get_opcodes()

[Michael Niedermayer]

ffmpeg | branch: release/4.0 | Michael Niedermayer <michael at niedermayer.cc> | Sun Mar  3 00:47:47 2019 +0100| [63383dea3b16bcf47c362950a2da1177e2693923] | committer: Michael Niedermayer

avcodec/dxv: Correct integer overflow in get_opcodes()

Fixes: 13099/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_DXV_fuzzer-5665598896340992
Fixes: signed integer overflow: 2147483647 + 7 cannot be represented in type 'int'

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 6e0b5d3a20e107860a34e90139b860d6b8219a1d)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=63383dea3b16bcf47c362950a2da1177e2693923
---

 libavcodec/dxv.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavcodec/dxv.c b/libavcodec/dxv.c
index bf53d7d706..aef5ec19dd 100644
--- a/libavcodec/dxv.c
+++ b/libavcodec/dxv.c
@@ -426,7 +426,8 @@ static int fill_optable(unsigned *table0, OpcodeTable *table1, int nb_elements)
 static int get_opcodes(GetByteContext *gb, uint32_t *table, uint8_t *dst, int op_size, int nb_elements)
 {
     OpcodeTable optable[1024];
-    int sum, x, val, lshift, rshift, ret, size_in_bits, i, idx;
+    int sum, x, val, lshift, rshift, ret, i, idx;
+    int64_t size_in_bits;
     unsigned endoffset, newoffset, offset;
     unsigned next;
     uint8_t *src = (uint8_t *)gb->buffer;