[FFmpeg-cvslog] vc1: avoid reading beyond the last line in vc1_draw_sprites()

Michael Niedermayer git at videolan.org
Thu Mar 1 22:40:13 CET 2012


ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Thu Mar  1 22:19:36 2012 +0100| [75d11b55d7c6f9417c047500171b8aa42b8b8f50] | committer: Michael Niedermayer

vc1: avoid reading beyond the last line in vc1_draw_sprites()

Fixes overread

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=75d11b55d7c6f9417c047500171b8aa42b8b8f50
---

 libavcodec/vc1dec.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavcodec/vc1dec.c b/libavcodec/vc1dec.c
index bffd7b8..2d3a94c 100644
--- a/libavcodec/vc1dec.c
+++ b/libavcodec/vc1dec.c
@@ -5072,7 +5072,7 @@ static void vc1_draw_sprites(VC1Context *v, SpriteData* sd)
                 if (!(xoff[sprite] & 0xFFFF) && xadv[sprite] == 1 << 16) {
                         src_h[sprite][0] = iplane + (xoff[sprite] >> 16) +  yline      * iline;
                     if (ysub[sprite])
-                        src_h[sprite][1] = iplane + (xoff[sprite] >> 16) + (yline + 1) * iline;
+                        src_h[sprite][1] = iplane + (xoff[sprite] >> 16) + FFMIN(yline + 1, (v->sprite_height>>!!plane)-1) * iline;
                 } else {
                     if (sr_cache[sprite][0] != yline) {
                         if (sr_cache[sprite][1] == yline) {
@@ -5084,7 +5084,7 @@ static void vc1_draw_sprites(VC1Context *v, SpriteData* sd)
                         }
                     }
                     if (ysub[sprite] && sr_cache[sprite][1] != yline + 1) {
-                        v->vc1dsp.sprite_h(v->sr_rows[sprite][1], iplane + (yline + 1) * iline, xoff[sprite], xadv[sprite], width);
+                        v->vc1dsp.sprite_h(v->sr_rows[sprite][1], iplane + FFMIN(yline + 1, (v->sprite_height>>!!plane)-1) * iline, xoff[sprite], xadv[sprite], width);
                         sr_cache[sprite][1] = yline + 1;
                     }
                     src_h[sprite][0] = v->sr_rows[sprite][0];



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