alsdec: validate time diff index

If begin is smaller than t, the subtraction 'begin -= t' wraps around,
because begin is unsigned. The same applies for end < t.

This causes segmentation faults.

Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit faf9fe2c22)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Andreas Cadhalpun 2015-04-18 20:09:28 +02:00 committed by Michael Niedermayer
parent 455bc87c8f
commit d18f8959b3
1 changed files with 8 additions and 0 deletions

View File

@ -1284,8 +1284,16 @@ static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,
if (ch[dep].time_diff_sign) {
t = -t;
if (t > 0 && begin < t) {
av_log(ctx->avctx, AV_LOG_ERROR, "begin %u smaller than time diff index %d.\n", begin, t);
return AVERROR_INVALIDDATA;
}
begin -= t;
} else {
if (t > 0 && end < t) {
av_log(ctx->avctx, AV_LOG_ERROR, "end %u smaller than time diff index %d.\n", end, t);
return AVERROR_INVALIDDATA;
}
end -= t;
}