[FFmpeg-devel] [PATCH 3/7] avformat/asfdec_f: Check sizeX against padding

Michael Niedermayer michael at niedermayer.cc
Fri Apr 23 20:50:52 EEST 2021


Fixes: signed integer overflow: 2147483607 + 64 cannot be represented in type 'int'
Fixes: 29102/clusterfuzz-testcase-minimized-ffmpeg_dem_ASF_fuzzer-6753897878257664

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/asfdec_f.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/asfdec_f.c b/libavformat/asfdec_f.c
index 27162e9559..18d637b1a4 100644
--- a/libavformat/asfdec_f.c
+++ b/libavformat/asfdec_f.c
@@ -415,7 +415,7 @@ static int asf_read_stream_properties(AVFormatContext *s, int64_t size)
         tag1                             = avio_rl32(pb);
         avio_skip(pb, 20);
         if (sizeX > 40) {
-            if (size < sizeX - 40)
+            if (size < sizeX - 40 || sizeX - 40 > INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE)
                 return AVERROR_INVALIDDATA;
             st->codecpar->extradata_size = ffio_limit(pb, sizeX - 40);
             st->codecpar->extradata      = av_mallocz(st->codecpar->extradata_size +
-- 
2.17.1



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