slirp: check data length while emulating ident function

While emulating identification protocol, tcp_emu() does not check
available space in the 'sc_rcv->sb_data' buffer. It could lead to
heap buffer overflow issue. Add check to avoid it.

Reported-by: Kira <864786842@qq.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
This commit is contained in:
Prasad J Pandit 2019-01-13 23:29:48 +05:30 committed by Samuel Thibault
parent 55ef9c617b
commit a7104eda7d

View File

@ -634,6 +634,11 @@ tcp_emu(struct socket *so, struct mbuf *m)
socklen_t addrlen = sizeof(struct sockaddr_in);
struct sbuf *so_rcv = &so->so_rcv;
if (m->m_len > so_rcv->sb_datalen
- (so_rcv->sb_wptr - so_rcv->sb_data)) {
return 1;
}
memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
so_rcv->sb_wptr += m->m_len;
so_rcv->sb_rptr += m->m_len;