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| author | Michael Niedermayer <michael@niedermayer.cc> | 2023-06-08 18:17:46 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2023-06-18 14:29:12 +0200 |
| commit | adfe003f518dac098ba9cdabcd6158fa55383710 (patch) | |
| tree | 6f33c551bbde37767540a96cd334595a35de5b5c | |
| parent | d7d3f1af2ab23cae1b2fc36afafc9872bc633808 (diff) | |
| download | ffmpeg-adfe003f518dac098ba9cdabcd6158fa55383710.tar.gz | |
avcodec/mpegvideo_dec: Add NULL pointer checks to MPV_motion_lowres()
This makes the null pointer checks match mpv_motion_internal()
Fixes: NULL pointer dereference
Fixes: 59671/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MPEG1VIDEO_fuzzer-4993004566609920
Fixes: 59678/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MPEGVIDEO_fuzzer-4893168991338496
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
| -rw-r--r-- | libavcodec/mpegvideo_dec.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/libavcodec/mpegvideo_dec.c b/libavcodec/mpegvideo_dec.c index c87ca77ae6..fcca147cd6 100644 --- a/libavcodec/mpegvideo_dec.c +++ b/libavcodec/mpegvideo_dec.c @@ -885,10 +885,9 @@ static inline void MPV_motion_lowres(MpegEncContext *s, s->mv[dir][1][0], s->mv[dir][1][1], block_s, mb_y); } else { - if (s->picture_structure != s->field_select[dir][0] + 1 && - s->pict_type != AV_PICTURE_TYPE_B && !s->first_field) { + if ( s->picture_structure != s->field_select[dir][0] + 1 && s->pict_type != AV_PICTURE_TYPE_B && !s->first_field + || !ref_picture[0]) { ref_picture = s->current_picture_ptr->f->data; - } mpeg_motion_lowres(s, dest_y, dest_cb, dest_cr, 0, 0, s->field_select[dir][0], @@ -901,8 +900,9 @@ static inline void MPV_motion_lowres(MpegEncContext *s, for (int i = 0; i < 2; i++) { uint8_t *const *ref2picture; - if (s->picture_structure == s->field_select[dir][i] + 1 || - s->pict_type == AV_PICTURE_TYPE_B || s->first_field) { + if ((s->picture_structure == s->field_select[dir][i] + 1 || + s->pict_type == AV_PICTURE_TYPE_B || s->first_field) && + ref_picture[0]) { ref2picture = ref_picture; } else { ref2picture = s->current_picture_ptr->f->data; @@ -933,6 +933,9 @@ static inline void MPV_motion_lowres(MpegEncContext *s, pix_op = s->h264chroma.avg_h264_chroma_pixels_tab; } } else { + if (!ref_picture[0]) { + ref_picture = s->current_picture_ptr->f->data; + } for (int i = 0; i < 2; i++) { mpeg_motion_lowres(s, dest_y, dest_cb, dest_cr, 0, 0, s->picture_structure != i + 1, |