avcodec/jpeg2000dec: fix context consistency with too large lowres

Fixes out of array accesses
Fixes Ticket2898

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2013-10-15 13:15:47 +02:00
parent 0a6ce255ab
commit a1b9004b76

View File

@ -370,11 +370,18 @@ static int get_cox(Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *c)
return AVERROR_INVALIDDATA;
}
if (c->nreslevels <= s->reduction_factor) {
/* we are forced to update reduction_factor as its requested value is
not compatible with this bitstream, and as we might have used it
already in setup earlier we have to fail this frame until
reinitialization is implemented */
av_log(s->avctx, AV_LOG_ERROR, "reduction_factor too large for this bitstream, max is %d\n", c->nreslevels - 1);
s->reduction_factor = c->nreslevels - 1;
return AVERROR(EINVAL);
}
/* compute number of resolution levels to decode */
if (c->nreslevels < s->reduction_factor)
c->nreslevels2decode = 1;
else
c->nreslevels2decode = c->nreslevels - s->reduction_factor;
c->nreslevels2decode = c->nreslevels - s->reduction_factor;
c->log2_cblk_width = (bytestream2_get_byteu(&s->g) & 15) + 2; // cblk width
c->log2_cblk_height = (bytestream2_get_byteu(&s->g) & 15) + 2; // cblk height