l2tp: fix error handling of PPPoL2TP socket options

Fix pppol2tp_[gs]etsockopt() so that they don't ignore errors returned by their helper functions.

Guillaume Nault (2):
l2tp: don't mask errors in pppol2tp_setsockopt()
l2tp: don't mask errors in pppol2tp_getsockopt()

 net/l2tp/l2tp_ppp.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

2.11.0

pppol2tp_setsockopt() unconditionally overwrites the error value returned by pppol2tp_tunnel_setsockopt() or pppol2tp_session_setsockopt(), thus hiding errors from userspace.

---
 net/l2tp/l2tp_ppp.c | 2 --
 1 file changed, 2 deletions(-)

index 861b255a2d51..973a9185b276 100644
@@ -1383,8 +1383,6 @@ static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
 	} else
 		err = pppol2tp_session_setsockopt(sk, session, optname, val);
 
-	err = 0;
-
 end_put_sess:
 	sock_put(sk);
 end:

2.11.0

pppol2tp_getsockopt() doesn't take into account the error code returned by pppol2tp_tunnel_getsockopt() or pppol2tp_session_getsockopt(). If error occurs there, pppol2tp_getsockopt() continues unconditionally and reports erroneous values.

---
 net/l2tp/l2tp_ppp.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

index 973a9185b276..32ea0f3d868c 100644
@@ -1505,8 +1505,13 @@ static int pppol2tp_getsockopt(struct socket *sock, int level, int optname,
 
 		err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
 		sock_put(ps->tunnel_sock);
-	} else
+		if (err)
+			goto end_put_sess;
+	} else {
 		err = pppol2tp_session_getsockopt(sk, session, optname, &val);
+		if (err)
+			goto end_put_sess;
+	}
 
 	err = -EFAULT;
 	if (put_user(len, optlen))

2.11.0

From: Guillaume Nault <[email protected]>
Date: Thu, 6 Apr 2017 18:31:18 +0200

Series applied, thanks.