mlpdec: set channel variables after checking them

This fixes out of array reads

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2012-04-19 19:50:54 +02:00
parent ab75ad0116
commit a9cd12ee2a

View File

@ -366,6 +366,7 @@ static int read_restart_header(MLPDecodeContext *m, GetBitContext *gbp,
const int max_matrix_channel = m->avctx->codec_id == CODEC_ID_MLP
? MAX_MATRIX_CHANNEL_MLP
: MAX_MATRIX_CHANNEL_TRUEHD;
int max_channel, min_channel, matrix_channel;
sync_word = get_bits(gbp, 13);
@ -384,18 +385,18 @@ static int read_restart_header(MLPDecodeContext *m, GetBitContext *gbp,
skip_bits(gbp, 16); /* Output timestamp */
s->min_channel = get_bits(gbp, 4);
s->max_channel = get_bits(gbp, 4);
s->max_matrix_channel = get_bits(gbp, 4);
min_channel = get_bits(gbp, 4);
max_channel = get_bits(gbp, 4);
matrix_channel = get_bits(gbp, 4);
if (s->max_matrix_channel > max_matrix_channel) {
if (matrix_channel > max_matrix_channel) {
av_log(m->avctx, AV_LOG_ERROR,
"Max matrix channel cannot be greater than %d.\n",
max_matrix_channel);
return AVERROR_INVALIDDATA;
}
if (s->max_channel != s->max_matrix_channel) {
if (max_channel != matrix_channel) {
av_log(m->avctx, AV_LOG_ERROR,
"Max channel must be equal max matrix channel.\n");
return AVERROR_INVALIDDATA;
@ -403,19 +404,23 @@ static int read_restart_header(MLPDecodeContext *m, GetBitContext *gbp,
/* This should happen for TrueHD streams with >6 channels and MLP's noise
* type. It is not yet known if this is allowed. */
if (s->max_channel > MAX_MATRIX_CHANNEL_MLP && !s->noise_type) {
if (max_channel > MAX_MATRIX_CHANNEL_MLP && !s->noise_type) {
av_log_ask_for_sample(m->avctx,
"Number of channels %d is larger than the maximum supported "
"by the decoder.\n", s->max_channel + 2);
"by the decoder.\n", max_channel + 2);
return AVERROR_PATCHWELCOME;
}
if (s->min_channel > s->max_channel) {
if (min_channel > max_channel) {
av_log(m->avctx, AV_LOG_ERROR,
"Substream min channel cannot be greater than max channel.\n");
return AVERROR_INVALIDDATA;
}
s->min_channel = min_channel;
s->max_channel = max_channel;
s->max_matrix_channel = matrix_channel;
if (m->avctx->request_channels > 0
&& s->max_channel + 1 >= m->avctx->request_channels
&& substr < m->max_decoded_substream) {