[FFmpeg-devel] [PATCH 1/3] avcodec/cbs_av1_syntax_template: Check num_y_points

[Michael Niedermayer]

"It is a requirement of bitstream conformance that num_y_points is less than or equal to 14."

Fixes: index 24 out of bounds for type 'uint8_t [24]'
Fixes: 19282/clusterfuzz-testcase-minimized-ffmpeg_BSF_AV1_FRAME_MERGE_fuzzer-5747424845103104

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavcodec/cbs_av1_syntax_template.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/cbs_av1_syntax_template.c b/libavcodec/cbs_av1_syntax_template.c
index 6c4816f964..5da54b695d 100644
--- a/libavcodec/cbs_av1_syntax_template.c
+++ b/libavcodec/cbs_av1_syntax_template.c
@@ -1155,7 +1155,7 @@ static int FUNC(film_grain_params)(CodedBitstreamContext *ctx, RWContext *rw,
         return 0;
     }
 
-    fb(4, num_y_points);
+    fc(4, num_y_points, 0, 14);
     for (i = 0; i < current->num_y_points; i++) {
         fbs(8, point_y_value[i],   1, i);
         fbs(8, point_y_scaling[i], 1, i);
-- 
2.24.0