From 209b9ff5c3f337da4a3d82e59b8815eca2737ffa Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 16 Oct 2020 11:13:19 +0200 Subject: [PATCH] avformat/asfdec_f: Check for negative ext_len Fixes: Infinite loop Fixes: 26376/clusterfuzz-testcase-minimized-ffmpeg_dem_PCM_U32LE_fuzzer-6050518830678016 Fixes: 26377/clusterfuzz-testcase-minimized-ffmpeg_dem_TY_fuzzer-4838195726123008 Fixes: 26384/clusterfuzz-testcase-minimized-ffmpeg_dem_G729_fuzzer-5173450337157120 Fixes: 26396/clusterfuzz-testcase-minimized-ffmpeg_dem_PCM_S24BE_fuzzer-5071092206796800 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavformat/asfdec_f.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/libavformat/asfdec_f.c b/libavformat/asfdec_f.c index ff9107d73f..5b4119a315 100644 --- a/libavformat/asfdec_f.c +++ b/libavformat/asfdec_f.c @@ -607,6 +607,8 @@ static int asf_read_ext_stream_properties(AVFormatContext *s, int64_t size) ff_get_guid(pb, &g); size = avio_rl16(pb); ext_len = avio_rl32(pb); + if (ext_len < 0) + return AVERROR_INVALIDDATA; avio_skip(pb, ext_len); if (stream_num < 128 && i < FF_ARRAY_ELEMS(asf->streams[stream_num].payload)) { ASFPayload *p = &asf->streams[stream_num].payload[i];