From db4555e2443dcacbfced4d818d32017bc9eeedf7 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 6 Feb 2026 22:37:53 +0100 Subject: [PATCH] avcodec/mdec: Check input space vs minimal block size Fixes: Timeout Fixes: 481006706/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MDEC_fuzzer-6122832651419648 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer (cherry picked from commit 40cafc25cfc435e91ff3862cd9489573f6a38dc1) Signed-off-by: Michael Niedermayer --- libavcodec/mdec.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/libavcodec/mdec.c b/libavcodec/mdec.c index 44b12471a9..cc14082ece 100644 --- a/libavcodec/mdec.c +++ b/libavcodec/mdec.c @@ -174,6 +174,9 @@ static int decode_frame(AVCodecContext *avctx, AVFrame *frame, int buf_size = avpkt->size; int ret; + if (a->mb_width * a->mb_height * 3 > buf_size) + return AVERROR_INVALIDDATA; + if ((ret = ff_thread_get_buffer(avctx, frame, 0)) < 0) return ret; frame->pict_type = AV_PICTURE_TYPE_I;