From 5a30b45c0fe4abaaf69ca8e465bf8113fee23626 Mon Sep 17 00:00:00 2001 From: Andreas Rheinhardt Date: Mon, 24 Jun 2024 01:38:17 +0200 Subject: [PATCH] avcodec/mpeg12dec: Don't adapt (last|next)_pic.linesize for field pics These values are not read anywhere. Furthermore, since commit fe6037fd04db8837dcdb9013f9c4ad4e7eb0592e the linesize values of the MPVWorkPictures were wrong for subsequent fields in a chain of B-pictures (as they are always doubled and no longer based upon the frame-linesizes) which can eventually lead to overflow. Finally, it makes no real sense to ever double the linesize of the reference pictures at all: Even when the current picture is a field, it can still reference both fields of reference pictures and therefore the linesize should allow to address both fields (for the same reason, data is not offset for reference pictures). libavcodec/mpeg12dec.c:1304:41: runtime error: signed integer overflow: 4611686018427387904 * 2 cannot be represented in type 'long' issue: 69732/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MPEGVIDEO_fuzzer-5123551179374592 Reviewed-by: Michael Niedermayer Signed-off-by: Andreas Rheinhardt --- libavcodec/mpeg12dec.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/libavcodec/mpeg12dec.c b/libavcodec/mpeg12dec.c index 09befdcc64..bb0a769e49 100644 --- a/libavcodec/mpeg12dec.c +++ b/libavcodec/mpeg12dec.c @@ -1278,8 +1278,6 @@ static int mpeg_field_start(Mpeg1Context *s1, const uint8_t *buf, int buf_size) s->cur_pic.linesize[i]); } s->cur_pic.linesize[i] *= 2; - s->last_pic.linesize[i] *= 2; - s->next_pic.linesize[i] *= 2; } }