rionet: fix NULL pointer dereference in rionet_remove

Function rionet_remove initializes local variable 'ndev' to NULL
and do nothing changes before the call to unregister_netdev(ndev),
this could cause a NULL pointer dereference.

Reported-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Yinglin Luan <synmyth@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 15 insertions, 13 deletions

diff --git a/drivers/net/rionet.c b/drivers/net/rionet.c
index 77c5092a6a40..5d3436d47edd 100644
--- a/drivers/net/rionet.c
+++ b/drivers/net/rionet.c
@@ -378,7 +378,7 @@ static int rionet_close(struct net_device *ndev)
 
 static void rionet_remove(struct rio_dev *rdev)
 {
-        struct net_device *ndev = NULL;
+        struct net_device *ndev = rio_get_drvdata(rdev);
         struct rionet_peer *peer, *tmp;
 
         free_pages((unsigned long)rionet_active, rdev->net->hport->sys_size ?
@@ -433,22 +433,12 @@ static const struct net_device_ops rionet_netdev_ops = {
         .ndo_set_mac_address    = eth_mac_addr,
 };
 
-static int rionet_setup_netdev(struct rio_mport *mport)
+static int rionet_setup_netdev(struct rio_mport *mport, struct net_device *ndev)
 {
         int rc = 0;
-        struct net_device *ndev = NULL;
         struct rionet_private *rnet;
         u16 device_id;
 
-        /* Allocate our net_device structure */
-        ndev = alloc_etherdev(sizeof(struct rionet_private));
-        if (ndev == NULL) {
-                printk(KERN_INFO "%s: could not allocate ethernet device.\n",
-                       DRV_NAME);
-                rc = -ENOMEM;
-                goto out;
-        }
-
         rionet_active = (struct rio_dev **)__get_free_pages(GFP_KERNEL,
                         mport->sys_size ? __fls(sizeof(void *)) + 4 : 0);
         if (!rionet_active) {
@@ -504,11 +494,21 @@ static int rionet_probe(struct rio_dev *rdev, const struct rio_device_id *id)
         int rc = -ENODEV;
         u32 lpef, lsrc_ops, ldst_ops;
         struct rionet_peer *peer;
+        struct net_device *ndev = NULL;
 
         /* If local device is not rionet capable, give up quickly */
         if (!rionet_capable)
                 goto out;
 
+        /* Allocate our net_device structure */
+        ndev = alloc_etherdev(sizeof(struct rionet_private));
+        if (ndev == NULL) {
+                printk(KERN_INFO "%s: could not allocate ethernet device.\n",
+                       DRV_NAME);
+                rc = -ENOMEM;
+                goto out;
+        }
+
         /*
          * First time through, make sure local device is rionet
          * capable, setup netdev,  and set flags so this is skipped
@@ -529,7 +529,7 @@ static int rionet_probe(struct rio_dev *rdev, const struct rio_device_id *id)
                         goto out;
                 }
 
-                rc = rionet_setup_netdev(rdev->net->hport);
+                rc = rionet_setup_netdev(rdev->net->hport, ndev);
                 rionet_check = 1;
         }
 
@@ -546,6 +546,8 @@ static int rionet_probe(struct rio_dev *rdev, const struct rio_device_id *id)
                 list_add_tail(&peer->node, &rionet_peers);
         }
 
+        rio_set_drvdata(rdev, ndev);
+
       out:
         return rc;
 }