[FFmpeg-cvslog] avcodec/scpr: mask bits to prevent out of array read

[Michael Niedermayer]

ffmpeg | branch: release/3.3 | Michael Niedermayer <michael at niedermayer.cc> | Tue May 16 02:22:37 2017 +0200| [21d50c185db03349282bc718f8aa4b7bb3d355a2] | committer: Michael Niedermayer

avcodec/scpr: mask bits to prevent out of array read

Fixes: 1615/clusterfuzz-testcase-minimized-6625214647500800

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
Reviewed-by: Paul B Mahol <onemda at gmail.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 5666b95c9f27efa6f9b1e1bb6c592b9a8d78bca5)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=21d50c185db03349282bc718f8aa4b7bb3d355a2
---

 libavcodec/scpr.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavcodec/scpr.c b/libavcodec/scpr.c
index 286fffbf35..b4cc7df07f 100644
--- a/libavcodec/scpr.c
+++ b/libavcodec/scpr.c
@@ -488,7 +488,7 @@ static int decompress_i(AVCodecContext *avctx, uint32_t *dst, int linesize)
 
         if (avctx->bits_per_coded_sample == 16) {
             cx1 = (clr & 0x3F00) >> 2;
-            cx = (clr & 0xFFFFFF) >> 16;
+            cx = (clr & 0x3FFFFF) >> 16;
         } else {
             cx1 = (clr & 0xFC00) >> 4;
             cx = (clr & 0xFFFFFF) >> 18;
@@ -726,7 +726,7 @@ static int decompress_p(AVCodecContext *avctx,
 
                     if (avctx->bits_per_coded_sample == 16) {
                         cx1 = (clr & 0x3F00) >> 2;
-                        cx = (clr & 0xFFFFFF) >> 16;
+                        cx = (clr & 0x3FFFFF) >> 16;
                     } else {
                         cx1 = (clr & 0xFC00) >> 4;
                         cx = (clr & 0xFFFFFF) >> 18;