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| author | wm4 <nfxjfg@googlemail.com> | 2015-01-05 04:45:26 +0100 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2015-01-05 05:13:27 +0100 |
| commit | 931f4313b2ec2e47bb34b6906ec53df6d3d45f9a (patch) | |
| tree | cd3577bae416bb2df38a2152f911e08b82afb216 | |
| parent | fd4c80177b006029c150d7bef96933d3d460ff4d (diff) | |
| download | ffmpeg-931f4313b2ec2e47bb34b6906ec53df6d3d45f9a.tar.gz | |
avcodec/dvdsubdec: fix out of bounds accesses
The code blindly trusted buffer offsets read from the file in the RLE
decoder. Explicitly check the offset. Also error out on other RLE
decoding errors.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit c9151de7c42553bb145be608df8513c1287f1f24)
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
| -rw-r--r-- | libavcodec/dvdsubdec.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/libavcodec/dvdsubdec.c b/libavcodec/dvdsubdec.c index cb268b8dfe..220063327e 100644 --- a/libavcodec/dvdsubdec.c +++ b/libavcodec/dvdsubdec.c @@ -99,6 +99,9 @@ static int decode_rle(uint8_t *bitmap, int linesize, int w, int h, int x, y, len, color; uint8_t *d; + if (start >= buf_size) + return -1; + bit_len = (buf_size - start) * 8; init_get_bits(&gb, buf + start, bit_len); @@ -340,10 +343,12 @@ static int decode_dvd_subtitles(DVDSubContext *ctx, AVSubtitle *sub_header, sub_header->rects[0] = av_mallocz(sizeof(AVSubtitleRect)); sub_header->num_rects = 1; sub_header->rects[0]->pict.data[0] = bitmap; - decode_rle(bitmap, w * 2, w, (h + 1) / 2, - buf, offset1, buf_size, is_8bit); - decode_rle(bitmap + w, w * 2, w, h / 2, - buf, offset2, buf_size, is_8bit); + if (decode_rle(bitmap, w * 2, w, (h + 1) / 2, + buf, offset1, buf_size, is_8bit) < 0) + goto fail; + if (decode_rle(bitmap + w, w * 2, w, h / 2, + buf, offset2, buf_size, is_8bit) < 0) + goto fail; sub_header->rects[0]->pict.data[1] = av_mallocz(AVPALETTE_SIZE); if (is_8bit) { if (yuv_palette == 0) |