[FFmpeg-cvslog] avcodec/diracdec: Use 64bit in calculation of codeblock coordinates

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Tue Oct 28 01:23:40 2014 +0100| [526886e6069636a918c8c04db17e864e3d8151c1] | committer: Michael Niedermayer

avcodec/diracdec: Use 64bit in calculation of codeblock coordinates

Fixes integer overflow
Fixes out of array read
Fixes: asan_heap-oob_107866c_42_041.drc
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=526886e6069636a918c8c04db17e864e3d8151c1
---

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

diff --git a/libavcodec/diracdec.c b/libavcodec/diracdec.c
index c03f45c..0511f1c 100644
--- a/libavcodec/diracdec.c
+++ b/libavcodec/diracdec.c
@@ -612,10 +612,10 @@ static av_always_inline void decode_subband_internal(DiracContext *s, SubBand *b
 
     top = 0;
     for (cb_y = 0; cb_y < cb_height; cb_y++) {
-        bottom = (b->height * (cb_y+1)) / cb_height;
+        bottom = (b->height * (cb_y+1LL)) / cb_height;
         left = 0;
         for (cb_x = 0; cb_x < cb_width; cb_x++) {
-            right = (b->width * (cb_x+1)) / cb_width;
+            right = (b->width * (cb_x+1LL)) / cb_width;
             codeblock(s, b, &gb, &c, left, right, top, bottom, blockcnt_one, is_arith);
             left = right;
         }