[FFmpeg-cvslog] avcodec/snow: Fix off by 1 error in run_buffer

[Michael Niedermayer]

ffmpeg | branch: release/4.2 | Michael Niedermayer <michael at niedermayer.cc> | Wed Jul 31 21:43:39 2024 +0200| [0d1d6587d0fc4cea872b48bc1077cb95a3c4be01] | committer: Michael Niedermayer

avcodec/snow: Fix off by 1 error in run_buffer

Fixes: out of array access
Fixes: 70741/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SNOW_fuzzer-5703668010647552

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 06f5ed40f8fceb2542add052c57608121eda2f41)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=0d1d6587d0fc4cea872b48bc1077cb95a3c4be01
---

 libavcodec/snow.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/snow.c b/libavcodec/snow.c
index a3e6afc86a..584be1578c 100644
--- a/libavcodec/snow.c
+++ b/libavcodec/snow.c
@@ -491,7 +491,7 @@ av_cold int ff_snow_common_init(AVCodecContext *avctx){
     FF_ALLOCZ_ARRAY_OR_GOTO(avctx, s->spatial_dwt_buffer,  width, height * sizeof(DWTELEM),  fail); //FIXME this does not belong here
     FF_ALLOCZ_ARRAY_OR_GOTO(avctx, s->temp_dwt_buffer,     width, sizeof(DWTELEM),  fail);
     FF_ALLOCZ_ARRAY_OR_GOTO(avctx, s->temp_idwt_buffer,    width, sizeof(IDWTELEM), fail);
-    FF_ALLOC_ARRAY_OR_GOTO(avctx,  s->run_buffer,          ((width + 1) >> 1), ((height + 1) >> 1) * sizeof(*s->run_buffer), fail);
+    FF_ALLOC_ARRAY_OR_GOTO(avctx,  s->run_buffer,          ((width + 1) >> 1) * ((height + 1) >> 1) + 1, sizeof(*s->run_buffer), fail);
 
     for(i=0; i<MAX_REF_FRAMES; i++) {
         for(j=0; j<MAX_REF_FRAMES; j++)