From 4542d66bb26f2d021c70a78e46f183c6675fc4c9 Mon Sep 17 00:00:00 2001
From: Feras Daoud <ferasda@mellanox.com>
Date: Wed, 14 Jun 2017 09:59:09 +0300
Subject: [PATCH] IB/ipoib: Fix memory leak in create child syscall

The flow of creating a new child goes through ipoib_vlan_add
which allocates a new interface and checks the rtnl_lock.

If the lock is taken, restart_syscall will be called to restart
the system call again. In this case we are not releasing the
already allocated interface, causing a leak.

Fixes: 9baa0b036410 ("IB/ipoib: Add rtnl_link_ops support")
Signed-off-by: Feras Daoud <ferasda@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
---
 drivers/infiniband/ulp/ipoib/ipoib_vlan.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_vlan.c b/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
index 1ee46194bbf5..081b33deff1b 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
@@ -133,13 +133,13 @@ int ipoib_vlan_add(struct net_device *pdev, unsigned short pkey)
 	snprintf(intf_name, sizeof intf_name, "%s.%04x",
 		 ppriv->dev->name, pkey);
 
+	if (!rtnl_trylock())
+		return restart_syscall();
+
 	priv = ipoib_intf_alloc(ppriv->ca, ppriv->port, intf_name);
 	if (!priv)
 		return -ENOMEM;
 
-	if (!rtnl_trylock())
-		return restart_syscall();
-
 	down_write(&ppriv->vlan_rwsem);
 
 	/*