[FFmpeg-devel] [PATCH 4/4] avformat/electronicarts: More chunk_size checks

Michael Niedermayer michael at niedermayer.cc
Tue Jan 12 23:51:16 EET 2021


Fixes: Timeout
Fixes: 26909/clusterfuzz-testcase-minimized-ffmpeg_dem_EA_fuzzer-6489496553783296

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavformat/electronicarts.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libavformat/electronicarts.c b/libavformat/electronicarts.c
index 4c292f29a2..a98a8d604e 100644
--- a/libavformat/electronicarts.c
+++ b/libavformat/electronicarts.c
@@ -607,10 +607,14 @@ static int ea_read_packet(AVFormatContext *s, AVPacket *pkt)
                 break;
             } else if (ea->audio_codec == AV_CODEC_ID_PCM_S16LE_PLANAR ||
                        ea->audio_codec == AV_CODEC_ID_MP3) {
+                if (chunk_size < 12)
+                    return AVERROR_INVALIDDATA;
                 num_samples = avio_rl32(pb);
                 avio_skip(pb, 8);
                 chunk_size -= 12;
             } else if (ea->audio_codec == AV_CODEC_ID_ADPCM_PSX) {
+                if (chunk_size < 8)
+                    return AVERROR_INVALIDDATA;
                 avio_skip(pb, 8);
                 chunk_size -= 8;
             }
@@ -693,6 +697,8 @@ static int ea_read_packet(AVFormatContext *s, AVPacket *pkt)
         case fVGT_TAG:
         case MADm_TAG:
         case MADe_TAG:
+            if (chunk_size > INT_MAX - 8)
+                return AVERROR_INVALIDDATA;
             avio_seek(pb, -8, SEEK_CUR);    // include chunk preamble
             chunk_size += 8;
             goto get_video_packet;
-- 
2.17.1



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