[FFmpeg-cvslog] avcodec/mss2: Check for repeat overflow

[Michael Niedermayer]

ffmpeg | branch: release/2.6 | Michael Niedermayer <michael at niedermayer.cc> | Sun Jan 10 12:19:48 2016 +0100| [aa5ae8b2136f9390dcc7e4dd31b1a2e557045449] | committer: Michael Niedermayer

avcodec/mss2: Check for repeat overflow

Fixes: mss2_left_shift.wmv

Found-by: Piotr Bandurski <ami_stuff at o2.pl>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit e273dade78943e22b71d0ddb67cd0d737fc26edf)

Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=aa5ae8b2136f9390dcc7e4dd31b1a2e557045449
---

 libavcodec/mss2.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/libavcodec/mss2.c b/libavcodec/mss2.c
index 4d53f8a..ea448da 100644
--- a/libavcodec/mss2.c
+++ b/libavcodec/mss2.c
@@ -209,8 +209,13 @@ static int decode_555(GetByteContext *gB, uint16_t *dst, int stride,
                     last_symbol = b << 8 | bytestream2_get_byte(gB);
                 else if (b > 129) {
                     repeat = 0;
-                    while (b-- > 130)
+                    while (b-- > 130) {
+                        if (repeat >= (INT_MAX >> 8) - 1) {
+                            av_log(NULL, AV_LOG_ERROR, "repeat overflow\n");
+                            return AVERROR_INVALIDDATA;
+                        }
                         repeat = (repeat << 8) + bytestream2_get_byte(gB) + 1;
+                    }
                     if (last_symbol == -2) {
                         int skip = FFMIN((unsigned)repeat, dst + w - p);
                         repeat -= skip;