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| author | Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com> | 2015-12-19 12:02:56 +0100 |
|---|---|---|
| committer | Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com> | 2015-12-20 16:13:44 +0100 |
| commit | bbe1c9839bb96f0a3988a3fdbb56283faf7f36fb (patch) | |
| tree | 8588d77473bc9bc68566cd91e5eb732ff3932659 | |
| parent | dcecc180a6ad9e05f2b1f5802ec04c95a4cc6a8d (diff) | |
| download | ffmpeg-bbe1c9839bb96f0a3988a3fdbb56283faf7f36fb.tar.gz | |
nutdec: reject negative value_len in read_sm_data
If it is negative, it can cause the byte position to move backwards in
avio_skip, which in turn makes sm_size negative and thus size larger
than the size of the packet buffer, causing invalid writes in avio_read.
Also fix potential overflow of avio_tell(bc) + value_len.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
(cherry picked from commit ce10f572c12b0d172c72d31d8c979afce602bf0c)
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
| -rw-r--r-- | libavformat/nutdec.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/libavformat/nutdec.c b/libavformat/nutdec.c index eec64235ef..df371dacb0 100644 --- a/libavformat/nutdec.c +++ b/libavformat/nutdec.c @@ -885,7 +885,7 @@ static int read_sm_data(AVFormatContext *s, AVIOContext *bc, AVPacket *pkt, int get_str(bc, type_str, sizeof(type_str)); value_len = ffio_read_varlen(bc); - if (avio_tell(bc) + value_len >= maxpos) + if (value_len < 0 || value_len >= maxpos - avio_tell(bc)) return AVERROR_INVALIDDATA; if (!strcmp(name, "Palette")) { dst = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE, value_len); |