rtpdec_asf: Fix integer underflow that could allow remote code execution

Fixes MSVR-11-0088.
Credit:  Jeong Wook Oh of Microsoft and Microsoft Vulnerability Research (MSVR)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: Martin Storsjö <martin@martin.st>
This commit is contained in:
Michael Niedermayer 2011-09-07 14:12:42 +02:00 committed by Martin Storsjö
parent 0ca36b4de7
commit 5ea091fb5a

View File

@ -233,8 +233,14 @@ static int asfrtp_parse_packet(AVFormatContext *s, PayloadContext *asf,
int cur_len = start_off + len_off - off;
int prev_len = out_len;
void *newmem;
out_len += cur_len;
asf->buf = av_realloc(asf->buf, out_len);
if (FFMIN(cur_len, len - off) < 0)
return -1;
newmem = av_realloc(asf->buf, out_len);
if (!newmem)
return -1;
asf->buf = newmem;
memcpy(asf->buf + prev_len, buf + off,
FFMIN(cur_len, len - off));
avio_skip(pb, cur_len);