[FFmpeg-cvslog] avcodec/rv60dec: Check NEXT/LAST availability

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sun Dec  8 02:07:52 2024 +0100| [61ff3047c577372cb3890b0e0eb6f556c0f8de8c] | committer: Michael Niedermayer

avcodec/rv60dec: Check NEXT/LAST availability

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
Reviewed-by: Peter Ross <pross at xvid.org>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=61ff3047c577372cb3890b0e0eb6f556c0f8de8c
---

 libavcodec/rv60dec.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/libavcodec/rv60dec.c b/libavcodec/rv60dec.c
index 4cc71dcd6e..0c2e03d737 100644
--- a/libavcodec/rv60dec.c
+++ b/libavcodec/rv60dec.c
@@ -61,7 +61,7 @@ enum IntraMode {
 };
 
 enum MVRefEnum {
-    MVREF_NONE,
+    MVREF_NONE = 0,
     MVREF_REF0,
     MVREF_REF1,
     MVREF_BREF,
@@ -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: