Unverified Commit 93af945a authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!13023 l2tp: prevent possible tunnel refcount underflow 

Merge Pull Request from: @ci-robot 
 
PR sync from: Liu Jian <liujian56@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/44QFUXAJZWSPWPKZUA7JAOCOSGRQGEWG/ 
 
https://gitee.com/src-openeuler/kernel/issues/IAYR9M 
 
Link:https://gitee.com/openeuler/kernel/pulls/13023

 

Reviewed-by: default avatarYue Haibing <yuehaibing@huawei.com>
Signed-off-by: default avatarZhang Peng <zhangpeng362@huawei.com>
parents 8975c967 2e2a17b4

net/l2tp/l2tp_core.c

+9 −6
Original line number Diff line number Diff line
@@ -387,6 +387,7 @@ int l2tp_session_register(struct l2tp_session *session, 
		l2tp_tunnel_inc_refcount(tunnel);

	}



	WRITE_ONCE(session->tunnel, tunnel);

	hlist_add_head_rcu(&session->hlist, head);

	spin_unlock_bh(&tunnel->hlist_lock);
@@ -698,7 +699,8 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, 
		if (!session->lns_mode && !session->send_seq) {

			trace_session_seqnum_lns_enable(session);

			session->send_seq = 1;

			l2tp_session_set_header_len(session, tunnel->version);

			l2tp_session_set_header_len(session, tunnel->version,

						    tunnel->encap);

		}

	} else {

		/* No sequence numbers.
@@ -719,7 +721,8 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, 
		if (!session->lns_mode && session->send_seq) {

			trace_session_seqnum_lns_disable(session);

			session->send_seq = 0;

			l2tp_session_set_header_len(session, tunnel->version);

			l2tp_session_set_header_len(session, tunnel->version,

						    tunnel->encap);

		} else if (session->send_seq) {

			pr_debug_ratelimited("%s: recv data has no seq numbers when required. Discarding.\n",

					     session->name);
@@ -1574,7 +1577,8 @@ EXPORT_SYMBOL_GPL(l2tp_session_delete); 
/* We come here whenever a session's send_seq, cookie_len or

 * l2specific_type parameters are set.

 */

void l2tp_session_set_header_len(struct l2tp_session *session, int version)

void l2tp_session_set_header_len(struct l2tp_session *session, int version,

				 enum l2tp_encap_type encap)

{

	if (version == L2TP_HDR_VER_2) {

		session->hdr_len = 6;
@@ -1583,7 +1587,7 @@ void l2tp_session_set_header_len(struct l2tp_session *session, int version) 
	} else {

		session->hdr_len = 4 + session->cookie_len;

		session->hdr_len += l2tp_get_l2specific_len(session);

		if (session->tunnel->encap == L2TP_ENCAPTYPE_UDP)

		if (encap == L2TP_ENCAPTYPE_UDP)

			session->hdr_len += 4;

	}

}
@@ -1597,7 +1601,6 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn 
	session = kzalloc(sizeof(*session) + priv_size, GFP_KERNEL);

	if (session) {

		session->magic = L2TP_SESSION_MAGIC;

		session->tunnel = tunnel;



		session->session_id = session_id;

		session->peer_session_id = peer_session_id;
@@ -1633,7 +1636,7 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn 
			memcpy(&session->peer_cookie[0], &cfg->peer_cookie[0], cfg->peer_cookie_len);

		}



		l2tp_session_set_header_len(session, tunnel->version);

		l2tp_session_set_header_len(session, tunnel->version, tunnel->encap);



		refcount_set(&session->ref_count, 1);

net/l2tp/l2tp_core.h

+2 −1
Original line number Diff line number Diff line
@@ -261,7 +261,8 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, 
int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb);



/* Transmit path helpers for sending packets over the tunnel socket. */

void l2tp_session_set_header_len(struct l2tp_session *session, int version);

void l2tp_session_set_header_len(struct l2tp_session *session, int version,

				 enum l2tp_encap_type encap);

int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb);



/* Pseudowire management.

net/l2tp/l2tp_netlink.c

+3 −1
Original line number Diff line number Diff line
@@ -690,8 +690,10 @@ static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *inf 
		session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);



	if (info->attrs[L2TP_ATTR_SEND_SEQ]) {

		struct l2tp_tunnel *tunnel = session->tunnel;



		session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);

		l2tp_session_set_header_len(session, session->tunnel->version);

		l2tp_session_set_header_len(session, tunnel->version, tunnel->encap);

	}



	if (info->attrs[L2TP_ATTR_LNS_MODE])

net/l2tp/l2tp_ppp.c

+2 −1
Original line number Diff line number Diff line
@@ -1203,7 +1203,8 @@ static int pppol2tp_session_setsockopt(struct sock *sk, 
			po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :

				PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;

		}

		l2tp_session_set_header_len(session, session->tunnel->version);

		l2tp_session_set_header_len(session, session->tunnel->version,

					    session->tunnel->encap);

		break;



	case PPPOL2TP_SO_LNSMODE: