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| author | Alex Converse <alex.converse@gmail.com> | 2012-01-25 15:46:14 -0800 |
|---|---|---|
| committer | Alex Converse <alex.converse@gmail.com> | 2012-01-30 16:49:15 -0800 |
| commit | f372ce119bd2458fa0b4ddfb2af3a36621df99f7 (patch) | |
| tree | 4437c317ccb2e742eefeda098414a02448912066 /libavcodec | |
| parent | a3a0691bdecf0b2ead2d06ea06c0c278733eef91 (diff) | |
| download | ffmpeg-f372ce119bd2458fa0b4ddfb2af3a36621df99f7.tar.gz | |
mp3dec: Fix a heap-buffer-overflow
In some cases, what is left to read from ptr is smaller than EXTRABYTES.
Based on a patch by Thierry Foucu <tfoucu@gmail.com>.
Signed-off-by: Alex Converse <alex.converse@gmail.com>
Diffstat (limited to 'libavcodec')
| -rw-r--r-- | libavcodec/mpegaudiodec.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/libavcodec/mpegaudiodec.c b/libavcodec/mpegaudiodec.c index 4ea5146ed6..af125d5587 100644 --- a/libavcodec/mpegaudiodec.c +++ b/libavcodec/mpegaudiodec.c @@ -1378,16 +1378,17 @@ static int mp_decode_layer3(MPADecodeContext *s) if (!s->adu_mode) { int skip; const uint8_t *ptr = s->gb.buffer + (get_bits_count(&s->gb)>>3); + int extrasize = av_clip(get_bits_left(&s->gb) >> 3, 0, EXTRABYTES); assert((get_bits_count(&s->gb) & 7) == 0); /* now we get bits from the main_data_begin offset */ av_dlog(s->avctx, "seekback: %d\n", main_data_begin); //av_log(NULL, AV_LOG_ERROR, "backstep:%d, lastbuf:%d\n", main_data_begin, s->last_buf_size); - memcpy(s->last_buf + s->last_buf_size, ptr, EXTRABYTES); + memcpy(s->last_buf + s->last_buf_size, ptr, extrasize); s->in_gb = s->gb; init_get_bits(&s->gb, s->last_buf, s->last_buf_size*8); #if !UNCHECKED_BITSTREAM_READER - s->gb.size_in_bits_plus8 += EXTRABYTES * 8; + s->gb.size_in_bits_plus8 += extrasize * 8; #endif s->last_buf_size <<= 3; for (gr = 0; gr < nb_granules && (s->last_buf_size >> 3) < main_data_begin; gr++) { |