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author | Andreas Rheinhardt <andreas.rheinhardt@gmail.com> | 2020-01-26 06:10:27 +0100 |
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committer | Andreas Rheinhardt <andreas.rheinhardt@gmail.com> | 2020-07-02 23:56:12 +0200 |
commit | 94ca3a00c8b6d37f7b66f873041981506e95b6ea (patch) | |
tree | 639af4b028ce77dfa34351fdebf3e05e1ae9d7ba | |
parent | 4ed977bbe5b03e39a0f4218316063b4ec9732e21 (diff) | |
download | ffmpeg-94ca3a00c8b6d37f7b66f873041981506e95b6ea.tar.gz |
avformat/matroskaenc: Check BlockAdditional size before use
Don't read a 64bit number before having checked that the data is at
least 8 bytes long.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 6e9cc964293bf1e0cca6a52b2938a20d711e4146)
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
-rw-r--r-- | libavformat/matroskaenc.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c index d8b36435b9..a52b38731f 100644 --- a/libavformat/matroskaenc.c +++ b/libavformat/matroskaenc.c @@ -2169,9 +2169,13 @@ static int mkv_write_block(AVFormatContext *s, AVIOContext *pb, AV_PKT_DATA_MATROSKA_BLOCKADDITIONAL, &side_data_size); if (side_data) { - additional_id = AV_RB64(side_data); - side_data += 8; - side_data_size -= 8; + if (side_data_size < 8) { + side_data_size = 0; + } else { + additional_id = AV_RB64(side_data); + side_data += 8; + side_data_size -= 8; + } } if ((side_data_size && additional_id == 1) || discard_padding) { |