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 <mich...@niedermayer.cc> --- libavcodec/mpegvideo_dec.c | 13 ++++++++----- 1 file 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, -- 2.17.1 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
