From b418ad75c2238d36b1d28050e7f37911b9ae64d4 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Thu, 9 Jun 2022 01:59:34 +0200 Subject: [PATCH] avcodec/flashsv: Clear pointers Fixes: Use after free Fixes: 47399/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FLASHSV2_fuzzer-5718646686613504 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/flashsv.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/libavcodec/flashsv.c b/libavcodec/flashsv.c index d8943d9cf8..4357b25d04 100644 --- a/libavcodec/flashsv.c +++ b/libavcodec/flashsv.c @@ -350,6 +350,9 @@ static int flashsv_decode_frame(AVCodecContext *avctx, AVFrame *rframe, if (err < 0) return err; s->keyframedata = avpkt->data; + if (s->blocks) + memset(s->blocks, 0, (v_blocks + !!v_part) * (h_blocks + !!h_part) * + sizeof(s->blocks[0])); } if(s->ver == 2 && !s->blocks) s->blocks = av_mallocz((v_blocks + !!v_part) * (h_blocks + !!h_part) * @@ -558,6 +561,7 @@ static av_cold int flashsv2_decode_end(AVCodecContext *avctx) FlashSVContext *s = avctx->priv_data; av_buffer_unref(&s->keyframedata_buf); + s->keyframedata = NULL; av_freep(&s->blocks); av_freep(&s->keyframe); flashsv_decode_end(avctx);