[FFmpeg-devel] [PATCH 5/6] avformat/flvdec: Check for nesting depth in amf_skip_tag()
Michael Niedermayer
michael at niedermayer.cc
Sun Jan 24 00:10:55 EET 2021
Fixes: out of array access
Fixes: 29440/clusterfuzz-testcase-minimized-ffmpeg_dem_KUX_fuzzer-5985279812960256.fuzz
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/flvdec.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/libavformat/flvdec.c b/libavformat/flvdec.c
index e15be0a221..4bc5e15dd2 100644
--- a/libavformat/flvdec.c
+++ b/libavformat/flvdec.c
@@ -842,10 +842,13 @@ static void clear_index_entries(AVFormatContext *s, int64_t pos)
}
}
-static int amf_skip_tag(AVIOContext *pb, AMFDataType type)
+static int amf_skip_tag(AVIOContext *pb, AMFDataType type, int depth)
{
int nb = -1, ret, parse_name = 1;
+ if (depth > MAX_DEPTH)
+ return AVERROR_PATCHWELCOME;
+
switch (type) {
case AMF_DATA_TYPE_NUMBER:
avio_skip(pb, 8);
@@ -870,7 +873,7 @@ static int amf_skip_tag(AVIOContext *pb, AMFDataType type)
}
avio_skip(pb, size);
}
- if ((ret = amf_skip_tag(pb, avio_r8(pb))) < 0)
+ if ((ret = amf_skip_tag(pb, avio_r8(pb), depth + 1)) < 0)
return ret;
}
break;
@@ -914,7 +917,7 @@ static int flv_data_packet(AVFormatContext *s, AVPacket *pkt,
else
break;
} else {
- if ((ret = amf_skip_tag(pb, type)) < 0)
+ if ((ret = amf_skip_tag(pb, type, 0)) < 0)
goto skip;
}
}
--
2.17.1
More information about the ffmpeg-devel
mailing list