4xm: check bitstream_size boundary before using it
Prevent buffer overread.
Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
(cherry picked from commit 59d7bb99b6
)
Signed-off-by: Reinhard Tartler <siretart@tauware.de>
This commit is contained in:

committed by
Reinhard Tartler

parent
5c54fc6195
commit
04c29196ad
@@ -733,6 +733,9 @@ static int decode_i_frame(FourXContext *f, const uint8_t *buf, int length)
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unsigned int prestream_size;
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unsigned int prestream_size;
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const uint8_t *prestream;
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const uint8_t *prestream;
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if (bitstream_size > (1 << 26))
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return AVERROR_INVALIDDATA;
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if (length < bitstream_size + 12) {
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if (length < bitstream_size + 12) {
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av_log(f->avctx, AV_LOG_ERROR, "packet size too small\n");
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av_log(f->avctx, AV_LOG_ERROR, "packet size too small\n");
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return AVERROR_INVALIDDATA;
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return AVERROR_INVALIDDATA;
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@@ -743,7 +746,6 @@ static int decode_i_frame(FourXContext *f, const uint8_t *buf, int length)
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prestream = buf + bitstream_size + 12;
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prestream = buf + bitstream_size + 12;
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if (prestream_size + bitstream_size + 12 != length
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if (prestream_size + bitstream_size + 12 != length
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|| bitstream_size > (1 << 26)
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|| prestream_size > (1 << 26)) {
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|| prestream_size > (1 << 26)) {
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av_log(f->avctx, AV_LOG_ERROR, "size mismatch %d %d %d\n",
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av_log(f->avctx, AV_LOG_ERROR, "size mismatch %d %d %d\n",
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prestream_size, bitstream_size, length);
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prestream_size, bitstream_size, length);
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