[FFmpeg-devel] [PATCH 4/6] avcodec/rv60dec: Check NEXT/LAST availability

[Michael Niedermayer]

Fixes: NULL ptr use
Fixes: 378634700/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_RV60_fuzzer-5008344043028480

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/rv60dec.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/libavcodec/rv60dec.c b/libavcodec/rv60dec.c
index 4cc71dcd6ee..528f91acf05 100644
--- a/libavcodec/rv60dec.c
+++ b/libavcodec/rv60dec.c
@@ -1745,15 +1745,24 @@ static int decode_cu_r(RV60Context * s, AVFrame * frame, ThreadContext * thread,
             bx = mv_x << 2;
             by = mv_y << 2;
 
+            if (!(mv.mvref&2)) {
+                if (!s->last_frame[LAST_PIC]->data[0]) {
+                    av_log(s->avctx, AV_LOG_ERROR, "missing reference frame\n");
+                    return AVERROR_INVALIDDATA;
+                }
+            }
+            if (mv.mvref & 6) {
+                if (!s->last_frame[NEXT_PIC]->data[0]) {
+                    av_log(s->avctx, AV_LOG_ERROR, "missing reference frame\n");
+                    return AVERROR_INVALIDDATA;
+                }
+            }
+
             switch (mv.mvref) {
             case MVREF_REF0:
                 mc(s, frame->data, frame->linesize, s->last_frame[LAST_PIC], bx, by, bw, bh, mv.f_mv, 0);
                 break;
             case MVREF_REF1:
-                if (!s->last_frame[NEXT_PIC]->data[0]) {
-                    av_log(s->avctx, AV_LOG_ERROR, "missing reference frame\n");
-                    return AVERROR_INVALIDDATA;
-                }
                 mc(s, frame->data, frame->linesize, s->last_frame[NEXT_PIC], bx, by, bw, bh, mv.f_mv, 0);
                 break;
             case MVREF_BREF:
-- 
2.47.0