From 32fb9198360402941e49aa878b9d33737b654f62 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 8 Dec 2019 20:18:07 +0100 Subject: [PATCH] avcodec/vc1dec: Check field_mode for sprites Fixes: Out of array read Fixes: 19263/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_VC1IMAGE_fuzzer-5389219325542400 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/vc1dec.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/libavcodec/vc1dec.c b/libavcodec/vc1dec.c index c81939c5a7..0a05989635 100644 --- a/libavcodec/vc1dec.c +++ b/libavcodec/vc1dec.c @@ -854,7 +854,12 @@ static int vc1_decode_frame(AVCodecContext *avctx, void *data, ret = AVERROR_INVALIDDATA; goto err; } - + if ((avctx->codec_id == AV_CODEC_ID_WMV3IMAGE || avctx->codec_id == AV_CODEC_ID_VC1IMAGE) + && v->field_mode) { + av_log(v->s.avctx, AV_LOG_ERROR, "Sprite decoder: expected Frames not Fields\n"); + ret = AVERROR_INVALIDDATA; + goto err; + } if ((s->mb_height >> v->field_mode) == 0) { av_log(v->s.avctx, AV_LOG_ERROR, "image too short\n"); ret = AVERROR_INVALIDDATA;