IB/ipoib: Fix memory leak in create child syscall

commit 4542d66bb26f2d021c70a78e46f183c6675fc4c9 upstream.

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>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_vlan.c b/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
index 4c83a970e7f3b38cd71fdbab3f438ceddc6fe524..946a1cceffd9205f0d2a24707c447e1de6bccbef 100644 (file)
--- a/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
@@ -133,13 +133,14 @@ int ipoib_vlan_add(struct net_device *pdev, unsigned short pkey)
 
        snprintf(intf_name, sizeof intf_name, "%s.%04x",
                 ppriv->dev->name, pkey);
-       priv = ipoib_intf_alloc(intf_name);
-       if (!priv)
-               return -ENOMEM;
 
        if (!rtnl_trylock())
                return restart_syscall();
 
+       priv = ipoib_intf_alloc(intf_name);
+       if (!priv)
+               return -ENOMEM;
+
        down_write(&ppriv->vlan_rwsem);
 
        /*