[FFmpeg-cvslog] avcodec/hevcdsp_template: stay within tables in sao_band_filter()

[Michael Niedermayer]

ffmpeg | branch: release/3.4 | Michael Niedermayer <michael at niedermayer.cc> | Thu Jun  9 22:21:55 2022 +0200| [0fcc72472604b9a08f83bb4fa65d0e8d8774a002] | committer: Michael Niedermayer

avcodec/hevcdsp_template: stay within tables in sao_band_filter()

Fixes: out of array read
Fixes: 47875/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HEVC_fuzzer-5719393113341952

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 9c5250a5612d4b32d79108de0c03945b2017963e)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=0fcc72472604b9a08f83bb4fa65d0e8d8774a002
---

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

diff --git a/libavcodec/hevcdsp_template.c b/libavcodec/hevcdsp_template.c
index 56cd9e605d..61425975cd 100644
--- a/libavcodec/hevcdsp_template.c
+++ b/libavcodec/hevcdsp_template.c
@@ -313,7 +313,7 @@ static void FUNC(sao_band_filter)(uint8_t *_dst, uint8_t *_src,
         offset_table[(k + sao_left_class) & 31] = sao_offset_val[k + 1];
     for (y = 0; y < height; y++) {
         for (x = 0; x < width; x++)
-            dst[x] = av_clip_pixel(src[x] + offset_table[src[x] >> shift]);
+            dst[x] = av_clip_pixel(src[x] + offset_table[(src[x] >> shift) & 31]);
         dst += stride_dst;
         src += stride_src;
     }