l2tp: don't mask errors in pppol2tp_getsockopt()

commit 321a52a39189d5e4af542f7dcdc07bba4545cf5d upstream.

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.

Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c
index a49964f..45c23bd 100644 (file)
--- a/net/l2tp/l2tp_ppp.c
+++ b/net/l2tp/l2tp_ppp.c
@@ -1509,8 +1509,13 @@ static int pppol2tp_getsockopt(struct socket *sock, int level,
 
                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, (int __user *) optlen))