From 20afd3a63a75a160f61a98a8dcfe06f527ea19b4 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Tue, 14 Sep 2021 20:16:27 +0200 Subject: [PATCH] avcodec/mxpegdec: Check for AVDISCARD_ALL Fixes: Fixes NULL pointer dereference Fixes: 36610/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MXPEG_fuzzer-6052641783283712 Fixes: 37907/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MXPEG_fuzzer-4725170850365440 Fixes: 37904/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MXPEG_fuzzer-6367889262247936 Fixes: 38085/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MXPEG_fuzzer-5175270823297024 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/mxpegdec.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/libavcodec/mxpegdec.c b/libavcodec/mxpegdec.c index 7c97a9340e..16e586c1e9 100644 --- a/libavcodec/mxpegdec.c +++ b/libavcodec/mxpegdec.c @@ -193,6 +193,9 @@ static int mxpeg_decode_frame(AVCodecContext *avctx, int start_code; int ret; + if (avctx->skip_frame == AVDISCARD_ALL) + return AVERROR_PATCHWELCOME; + buf_ptr = buf; buf_end = buf + buf_size; jpg->got_picture = 0;