[FFmpeg-cvslog] avutil/lzo: Fix integer overflow

[Michael Niedermayer]

ffmpeg | branch: release/1.0 | Michael Niedermayer <michaelni at gmx.at> | Fri Jun 20 03:15:28 2014 +0200| [7b5c706494a775b2b0d0e0a38448610802eef8f4] | committer: Michael Niedermayer

avutil/lzo: Fix integer overflow

Embargoed-till: 2014-06-27 requested by researcher, but embargo broken by libav today (git and mailing list)

Fixes: LMS-2014-06-16-4
Found-by: "Don A. Bailey" <donb at securitymouse.com>
See: ccda51b14c0fcae2fad73a24872dce75a7964996
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
(cherry picked from commit d6af26c55c1ea30f85a7d9edbc373f53be1743ee)

Conflicts:

	libavutil/lzo.c

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=7b5c706494a775b2b0d0e0a38448610802eef8f4
---

 libavutil/lzo.c |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/libavutil/lzo.c b/libavutil/lzo.c
index 1c65e2f..f6c6329 100644
--- a/libavutil/lzo.c
+++ b/libavutil/lzo.c
@@ -62,7 +62,13 @@ static inline int get_byte(LZOContext *c) {
 static inline int get_len(LZOContext *c, int x, int mask) {
     int cnt = x & mask;
     if (!cnt) {
-        while (!(x = get_byte(c))) cnt += 255;
+        while (!(x = get_byte(c))) {
+            if (cnt >= INT_MAX - 1000) {
+                c->error |= AV_LZO_ERROR;
+                break;
+            }
+            cnt += 255;
+        }
         cnt += mask + x;
     }
     return cnt;