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| author | Luca Barbato <lu_zero@gentoo.org> | 2013-06-07 16:18:22 +0200 |
|---|---|---|
| committer | Luca Barbato <lu_zero@gentoo.org> | 2013-06-16 15:54:23 +0200 |
| commit | d33b0f72245da71f7121b08116ef8732731f5adf (patch) | |
| tree | fdd293f292a245e72093d6dc18a9e11b6ec8f2e6 | |
| parent | 6ddc1eb037042da814a62aa7f54517a897f0bdad (diff) | |
| download | ffmpeg-d33b0f72245da71f7121b08116ef8732731f5adf.tar.gz | |
4xm: do not overread the prestream buffer
Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
(cherry picked from commit be373cb50d3c411366fec7eef2eb3681abe48f96)
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
| -rw-r--r-- | libavcodec/4xm.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/libavcodec/4xm.c b/libavcodec/4xm.c index 493e2ad152..5602f62026 100644 --- a/libavcodec/4xm.c +++ b/libavcodec/4xm.c @@ -576,7 +576,8 @@ static int decode_i_mb(FourXContext *f) } static const uint8_t *read_huffman_tables(FourXContext *f, - const uint8_t * const buf) + const uint8_t * const buf, + int len) { int frequency[512] = { 0 }; uint8_t flag[512]; @@ -594,12 +595,20 @@ static const uint8_t *read_huffman_tables(FourXContext *f, for (;;) { int i; + len -= end - start + 1; + + if (end < start || len < 0) + return NULL; + for (i = start; i <= end; i++) frequency[i] = *ptr++; start = *ptr++; if (start == 0) break; + if (--len < 0) + return NULL; + end = *ptr++; } frequency[256] = 1; @@ -741,7 +750,7 @@ static int decode_i_frame(FourXContext *f, const uint8_t *buf, int length) return -1; } - prestream = read_huffman_tables(f, prestream); + prestream = read_huffman_tables(f, prestream, prestream_size); if (!prestream) { av_log(f->avctx, AV_LOG_ERROR, "Error reading Huffman tables.\n"); return AVERROR_INVALIDDATA; |