cdgraphics: switch to bytestream2
Fixes possible invalid memory accesses on corrupted data.
CC:libav-stable@libav.org
Bug-ID: CVE-2013-3674
(cherry picked from commit a1599f3f7e
)
Signed-off-by: Anton Khirnov <anton@khirnov.net>
This commit is contained in:
@@ -269,7 +269,7 @@ static void cdg_scroll(CDGraphicsContext *cc, uint8_t *data,
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static int cdg_decode_frame(AVCodecContext *avctx,
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void *data, int *got_frame, AVPacket *avpkt)
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{
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const uint8_t *buf = avpkt->data;
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GetByteContext gb;
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int buf_size = avpkt->size;
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int ret;
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uint8_t command, inst;
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@@ -277,10 +277,8 @@ static int cdg_decode_frame(AVCodecContext *avctx,
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AVFrame new_frame;
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CDGraphicsContext *cc = avctx->priv_data;
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if (buf_size < CDG_MINIMUM_PKT_SIZE) {
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av_log(avctx, AV_LOG_ERROR, "buffer too small for decoder\n");
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return AVERROR(EINVAL);
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}
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bytestream2_init(&gb, avpkt->data, avpkt->size);
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ret = avctx->reget_buffer(avctx, &cc->frame);
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if (ret) {
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@@ -288,11 +286,11 @@ static int cdg_decode_frame(AVCodecContext *avctx,
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return ret;
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}
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command = bytestream_get_byte(&buf);
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inst = bytestream_get_byte(&buf);
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command = bytestream2_get_byte(&gb);
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inst = bytestream2_get_byte(&gb);
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inst &= CDG_MASK;
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buf += 2; /// skipping 2 unneeded bytes
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bytestream_get_buffer(&buf, cdg_data, buf_size - CDG_HEADER_SIZE);
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bytestream2_skip(&gb, 2);
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bytestream2_get_buffer(&gb, cdg_data, sizeof(cdg_data));
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if ((command & CDG_MASK) == CDG_COMMAND) {
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switch (inst) {
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