diff options
| author | Michael Niedermayer <michaelni@gmx.at> | 2013-04-16 16:41:21 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2013-04-16 17:04:16 +0200 |
| commit | 6b657ac7889738b9ab38924cca4e7c418f6fbc38 (patch) | |
| tree | c9e89a63c76e86d34d3e5e2319c44aa330505196 /libavcodec/c93.c | |
| parent | e701cd96c2d5dc034e7615967d208db3d953e111 (diff) | |
| download | ffmpeg-6b657ac7889738b9ab38924cca4e7c418f6fbc38.tar.gz | |
avcodec/c93: Check for block overlap.
Fixes overlapping memcpy()
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Diffstat (limited to 'libavcodec/c93.c')
| -rw-r--r-- | libavcodec/c93.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/libavcodec/c93.c b/libavcodec/c93.c index 9aaa3ee780..c51f2fa9de 100644 --- a/libavcodec/c93.c +++ b/libavcodec/c93.c @@ -168,7 +168,14 @@ static int decode_frame(AVCodecContext *avctx, void *data, case C93_4X4_FROM_PREV: for (j = 0; j < 8; j += 4) { for (i = 0; i < 8; i += 4) { - offset = bytestream2_get_le16(&gb); + int offset = bytestream2_get_le16(&gb); + int from_x = offset % WIDTH; + int from_y = offset / WIDTH; + if (block_type == C93_4X4_FROM_CURR && from_y == y+j && + (FFABS(from_x - x-i) < 4 || FFABS(from_x - x-i) > WIDTH-4)) { + avpriv_request_sample(avctx, "block overlap %d %d %d %d\n", from_x, x+i, from_y, y+j); + return AVERROR_INVALIDDATA; + } if ((ret = copy_block(avctx, &out[j*stride+i], copy_from, offset, 4, stride)) < 0) return ret; |