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author | Justin Ruggles <justin.ruggles@gmail.com> | 2008-12-08 03:13:20 +0000 |
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committer | Justin Ruggles <justin.ruggles@gmail.com> | 2008-12-08 03:13:20 +0000 |
commit | 72a6244b5d554d7fdfdeb04c174750c7a2c52f83 (patch) | |
tree | 8e9f106f4681f2e6e537e5c01ec7eb51ce835951 /libavcodec | |
parent | b9f382c8ef55bd2b1a6821bf060e848deda372f1 (diff) | |
download | ffmpeg-72a6244b5d554d7fdfdeb04c174750c7a2c52f83.tar.gz |
ac3: detect dba errors and prevent writing past end of array
Originally committed as revision 16034 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec')
-rw-r--r-- | libavcodec/ac3.c | 11 | ||||
-rw-r--r-- | libavcodec/ac3.h | 3 | ||||
-rw-r--r-- | libavcodec/ac3dec.c | 7 |
3 files changed, 15 insertions, 6 deletions
diff --git a/libavcodec/ac3.c b/libavcodec/ac3.c index e4117f1a15..2335106b17 100644 --- a/libavcodec/ac3.c +++ b/libavcodec/ac3.c @@ -80,7 +80,7 @@ void ff_ac3_bit_alloc_calc_psd(int8_t *exp, int start, int end, int16_t *psd, } while (end > band_start_tab[k]); } -void ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *band_psd, +int ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *band_psd, int start, int end, int fast_gain, int is_lfe, int dba_mode, int dba_nsegs, uint8_t *dba_offsets, uint8_t *dba_lengths, uint8_t *dba_values, @@ -156,9 +156,13 @@ void ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *band_psd, if (dba_mode == DBA_REUSE || dba_mode == DBA_NEW) { int band, seg, delta; + if (dba_nsegs >= 8) + return -1; band = 0; - for (seg = 0; seg < FFMIN(8, dba_nsegs); seg++) { - band = FFMIN(49, band + dba_offsets[seg]); + for (seg = 0; seg < dba_nsegs; seg++) { + band += dba_offsets[seg]; + if (band >= 50 || dba_lengths[seg] > 50-band) + return -1; if (dba_values[seg] >= 4) { delta = (dba_values[seg] - 3) << 7; } else { @@ -170,6 +174,7 @@ void ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *band_psd, } } } + return 0; } void ff_ac3_bit_alloc_calc_bap(int16_t *mask, int16_t *psd, int start, int end, diff --git a/libavcodec/ac3.h b/libavcodec/ac3.h index 1f5a7115d7..5ece9acf84 100644 --- a/libavcodec/ac3.h +++ b/libavcodec/ac3.h @@ -149,8 +149,9 @@ void ff_ac3_bit_alloc_calc_psd(int8_t *exp, int start, int end, int16_t *psd, * @param[in] dba_lengths length of each segment * @param[in] dba_values delta bit allocation for each segment * @param[out] mask calculated masking curve + * @return returns 0 for success, non-zero for error */ -void ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *band_psd, +int ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *band_psd, int start, int end, int fast_gain, int is_lfe, int dba_mode, int dba_nsegs, uint8_t *dba_offsets, uint8_t *dba_lengths, uint8_t *dba_values, diff --git a/libavcodec/ac3dec.c b/libavcodec/ac3dec.c index 291d8f3ab4..c7c240cdb4 100644 --- a/libavcodec/ac3dec.c +++ b/libavcodec/ac3dec.c @@ -1133,12 +1133,15 @@ static int decode_audio_block(AC3DecodeContext *s, int blk) if(bit_alloc_stages[ch] > 1) { /* Compute excitation function, Compute masking curve, and Apply delta bit allocation */ - ff_ac3_bit_alloc_calc_mask(&s->bit_alloc_params, s->band_psd[ch], + if (ff_ac3_bit_alloc_calc_mask(&s->bit_alloc_params, s->band_psd[ch], s->start_freq[ch], s->end_freq[ch], s->fast_gain[ch], (ch == s->lfe_ch), s->dba_mode[ch], s->dba_nsegs[ch], s->dba_offsets[ch], s->dba_lengths[ch], - s->dba_values[ch], s->mask[ch]); + s->dba_values[ch], s->mask[ch])) { + av_log(s->avctx, AV_LOG_ERROR, "error in bit allocation\n"); + return -1; + } } if(bit_alloc_stages[ch] > 0) { /* Compute bit allocation */ |