diff options
| author | Michael Niedermayer <michaelni@gmx.at> | 2011-12-20 20:51:53 +0400 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2011-12-20 21:07:08 +0400 |
| commit | a8469223f6bb756a44f6579439fcae24ccc739b1 (patch) | |
| tree | 784be77bfcbe77f8828450fd02af60ea903604e7 /libavcodec/alac.c | |
| parent | 65f0f9183b99881af58e90e3ae2ad8b0181d52f1 (diff) | |
alac: Check for bitstream overread
Fixes Ticket801
Bug found by: Oana Stratulat
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Diffstat (limited to 'libavcodec/alac.c')
| -rw-r--r-- | libavcodec/alac.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/libavcodec/alac.c b/libavcodec/alac.c index 2788238c78..c08d2848ed 100644 --- a/libavcodec/alac.c +++ b/libavcodec/alac.c @@ -112,7 +112,7 @@ static inline int decode_scalar(GetBitContext *gb, int k, int limit, int readsam return x; } -static void bastardized_rice_decompress(ALACContext *alac, +static int bastardized_rice_decompress(ALACContext *alac, int32_t *output_buffer, int output_size, int readsamplesize, /* arg_10 */ @@ -134,6 +134,9 @@ static void bastardized_rice_decompress(ALACContext *alac, /* standard rice encoding */ int k; /* size of extra bits */ + if(get_bits_left(&alac->gb) <= 0) + return -1; + /* read k, that is bits as is */ k = av_log2((history >> 9) + 3); x= decode_scalar(&alac->gb, k, rice_kmodifier, readsamplesize); @@ -179,6 +182,7 @@ static void bastardized_rice_decompress(ALACContext *alac, history = 0; } } + return 0; } static inline int sign_only(int v) @@ -442,12 +446,14 @@ static int alac_decode_frame(AVCodecContext *avctx, void *data, if (alac->extra_bits) { for (i = 0; i < outputsamples; i++) { + if(get_bits_left(&alac->gb) <= 0) + return -1; for (ch = 0; ch < channels; ch++) alac->extra_bits_buffer[ch][i] = get_bits(&alac->gb, alac->extra_bits); } } for (ch = 0; ch < channels; ch++) { - bastardized_rice_decompress(alac, + int ret = bastardized_rice_decompress(alac, alac->predicterror_buffer[ch], outputsamples, readsamplesize, @@ -455,6 +461,8 @@ static int alac_decode_frame(AVCodecContext *avctx, void *data, alac->setinfo_rice_kmodifier, ricemodifier[ch] * alac->setinfo_rice_historymult / 4, (1 << alac->setinfo_rice_kmodifier) - 1); + if(ret<0) + return ret; if (prediction_type[ch] == 0) { /* adaptive fir */ @@ -478,6 +486,8 @@ static int alac_decode_frame(AVCodecContext *avctx, void *data, } else { /* not compressed, easy case */ for (i = 0; i < outputsamples; i++) { + if(get_bits_left(&alac->gb) <= 0) + return -1; for (ch = 0; ch < channels; ch++) { alac->outputsamples_buffer[ch][i] = get_sbits_long(&alac->gb, alac->setinfo_sample_size); |