smacker: error out if palette copy-with-offset overruns palette size.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
This commit is contained in:
Ronald S. Bultje 2012-03-06 17:24:20 -08:00
parent a55d5bdc6e
commit a93b572ae4

View File

@ -265,8 +265,15 @@ static int smacker_read_packet(AVFormatContext *s, AVPacket *pkt)
sz += (t & 0x7F) + 1;
pal += ((t & 0x7F) + 1) * 3;
} else if(t & 0x40){ /* copy with offset */
off = avio_r8(s->pb) * 3;
off = avio_r8(s->pb);
j = (t & 0x3F) + 1;
if (off + j > 0xff) {
av_log(s, AV_LOG_ERROR,
"Invalid palette update, offset=%d length=%d extends beyond palette size\n",
off, j);
return AVERROR_INVALIDDATA;
}
off *= 3;
while(j-- && sz < 256) {
*pal++ = oldpal[off + 0];
*pal++ = oldpal[off + 1];