netdev - [PATCH net 4/4] l2tp: clean up stale tunnel or session in pppol2tp

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Date:   Wed, 13 Jun 2018 15:09:21 +0200
From:   Guillaume Nault <g.nault@...halink.fr>
To:     netdev@...r.kernel.org
Cc:     James Chapman <jchapman@...alix.com>
Subject: [PATCH net 4/4] l2tp: clean up stale tunnel or session in
 pppol2tp_connect's error path

pppol2tp_connect() may create a tunnel or a session. Remove them in
case of error.

Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: Guillaume Nault <g.nault@...halink.fr>
---
 net/l2tp/l2tp_ppp.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c
index 1b24f76ae210..f429fed06a1e 100644
--- a/net/l2tp/l2tp_ppp.c
+++ b/net/l2tp/l2tp_ppp.c
@@ -612,6 +612,8 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
 	u32 session_id, peer_session_id;
 	bool drop_refcnt = false;
 	bool drop_tunnel = false;
+	bool new_session = false;
+	bool new_tunnel = false;
 	int ver = 2;
 	int fd;
 
@@ -722,6 +724,7 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
 				goto end;
 			}
 			drop_tunnel = true;
+			new_tunnel = true;
 		}
 	} else {
 		/* Error if we can't find the tunnel */
@@ -788,6 +791,7 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
 			goto end;
 		}
 		drop_refcnt = true;
+		new_session = true;
 	}
 
 	/* Special case: if source & dest session_id == 0x0000, this
@@ -834,6 +838,12 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
 		  session->name);
 
 end:
+	if (error) {
+		if (new_session)
+			l2tp_session_delete(session);
+		if (new_tunnel)
+			l2tp_tunnel_delete(tunnel);
+	}
 	if (drop_refcnt)
 		l2tp_session_dec_refcount(session);
 	if (drop_tunnel)
-- 
2.17.1