[FFmpeg-cvslog] avcodec/jpeg2000dec: More completely check cdef

[Michael Niedermayer]

ffmpeg | branch: release/2.7 | Michael Niedermayer <michael at niedermayer.cc> | Wed Jan 27 17:13:10 2016 +0100| [12f256a729a8d9f1f1ae37dc14fb4437b935b133] | committer: Michael Niedermayer

avcodec/jpeg2000dec: More completely check cdef

Fixes out of array access
Fixes: j2k-poc.bin

Found-by: Lucas Leong <wmliang.tw at gmail.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 0aada30510d809bccfd539a90ea37b61188f2cb4)

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=12f256a729a8d9f1f1ae37dc14fb4437b935b133
---

 libavcodec/jpeg2000dec.c |   14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
index 54006af..9e6e1b5 100644
--- a/libavcodec/jpeg2000dec.c
+++ b/libavcodec/jpeg2000dec.c
@@ -1286,11 +1286,15 @@ static int jpeg2000_decode_tile(Jpeg2000DecoderContext *s, Jpeg2000Tile *tile,
     if (tile->codsty[0].mct)
         mct_decode(s, tile);
 
-    if (s->cdef[0] < 0) {
-        for (x = 0; x < s->ncomponents; x++)
-            s->cdef[x] = x + 1;
-        if ((s->ncomponents & 1) == 0)
-            s->cdef[s->ncomponents-1] = 0;
+    for (x = 0; x < s->ncomponents; x++) {
+        if (s->cdef[x] < 0) {
+            for (x = 0; x < s->ncomponents; x++) {
+                s->cdef[x] = x + 1;
+            }
+            if ((s->ncomponents & 1) == 0)
+                s->cdef[s->ncomponents-1] = 0;
+            break;
+        }
     }
 
     if (s->precision <= 8) {