[FFmpeg-cvslog] avcodec/jpeg2000dec: prevent out of array accesses in pixel addressing

[Michael Niedermayer]

ffmpeg | branch: release/2.0 | Michael Niedermayer <michaelni at gmx.at> | Sun Oct 13 21:18:23 2013 +0200| [93f26b79926cf311784ce939ba570cf282e15b5c] | committer: Michael Niedermayer

avcodec/jpeg2000dec: prevent out of array accesses in pixel addressing

Fixes Ticket2921

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
(cherry picked from commit fe448cd28d674c3eff3072552eae366d0b659ce9)

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=93f26b79926cf311784ce939ba570cf282e15b5c
---

 libavcodec/jpeg2000dec.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
index 4fe9136..3856d7b 100644
--- a/libavcodec/jpeg2000dec.c
+++ b/libavcodec/jpeg2000dec.c
@@ -1273,12 +1273,12 @@ static int jpeg2000_decode_tile(Jpeg2000DecoderContext *s, Jpeg2000Tile *tile,
 
 
             y    = tile->comp[compno].coord[1][0] - s->image_offset_y;
-            line = picture->data[plane] + y * picture->linesize[plane];
+            line = picture->data[plane] + y / s->cdy[compno] * picture->linesize[plane];
             for (; y < tile->comp[compno].coord[1][1] - s->image_offset_y; y += s->cdy[compno]) {
                 uint8_t *dst;
 
                 x   = tile->comp[compno].coord[0][0] - s->image_offset_x;
-                dst = line + x * pixelsize + compno*!planar;
+                dst = line + x / s->cdx[compno] * pixelsize + compno*!planar;
 
                 if (codsty->transform == FF_DWT97) {
                     for (; x < w; x += s->cdx[compno]) {
@@ -1319,12 +1319,12 @@ static int jpeg2000_decode_tile(Jpeg2000DecoderContext *s, Jpeg2000Tile *tile,
                 plane = s->cdef[compno] ? s->cdef[compno]-1 : (s->ncomponents-1);
 
             y     = tile->comp[compno].coord[1][0] - s->image_offset_y;
-            linel = (uint16_t *)picture->data[plane] + y * (picture->linesize[plane] >> 1);
+            linel = (uint16_t *)picture->data[plane] + y / s->cdy[compno] * (picture->linesize[plane] >> 1);
             for (; y < tile->comp[compno].coord[1][1] - s->image_offset_y; y += s->cdy[compno]) {
                 uint16_t *dst;
 
                 x   = tile->comp[compno].coord[0][0] - s->image_offset_x;
-                dst = linel + (x * pixelsize + compno*!planar);
+                dst = linel + (x / s->cdx[compno] * pixelsize + compno*!planar);
                 if (codsty->transform == FF_DWT97) {
                     for (; x < w; x += s-> cdx[compno]) {
                         int  val = lrintf(*datap) + (1 << (cbps - 1));