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| author | Anton Khirnov <anton@khirnov.net> | 2016-12-17 15:07:51 +0100 |
|---|---|---|
| committer | Anton Khirnov <anton@khirnov.net> | 2016-12-19 08:15:42 +0100 |
| commit | e807491fc6a336e4becc0cbc981274a8fde18aba (patch) | |
| tree | a7f7cc0f4533752ae197fbbc94d4a63cc16d4059 | |
| parent | 58405de0951a843765625159402870c1eea3c3b1 (diff) | |
| download | ffmpeg-e807491fc6a336e4becc0cbc981274a8fde18aba.tar.gz | |
mpeg12dec: avoid signed overflow in bitrate calculation
CC: libav-stable@libav.org
Bug-Id: 981
Found-By: Agostino Sarubbo
| -rw-r--r-- | libavcodec/mpeg12dec.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/libavcodec/mpeg12dec.c b/libavcodec/mpeg12dec.c index 2d9c99d63f..310169becc 100644 --- a/libavcodec/mpeg12dec.c +++ b/libavcodec/mpeg12dec.c @@ -1358,8 +1358,17 @@ static void mpeg_decode_sequence_extension(Mpeg1Context *s1) vert_size_ext = get_bits(&s->gb, 2); s->width |= (horiz_size_ext << 12); s->height |= (vert_size_ext << 12); - bit_rate_ext = get_bits(&s->gb, 12); /* XXX: handle it */ - s->bit_rate += (bit_rate_ext << 18) * 400; + + bit_rate_ext = get_bits(&s->gb, 12) << 18; + if (bit_rate_ext < INT_MAX / 400 && + bit_rate_ext * 400 < INT_MAX - s->bit_rate) { + s->bit_rate += bit_rate_ext * 400; + } else { + av_log(s->avctx, AV_LOG_WARNING, "Invalid bit rate extension value: %d\n", + bit_rate_ext >> 18); + s->bit_rate = 0; + } + skip_bits1(&s->gb); /* marker */ s->avctx->rc_buffer_size += get_bits(&s->gb, 8) * 1024 * 16 << 10; |