tap: reference to KVA of an unloaded module causes kernel panic

[sfrench/cifs-2.6.git] / drivers / net / tap.c

diff --git a/drivers/net/tap.c b/drivers/net/tap.c
index 21b71ae947fdbc2e3bbf7d5ef7c17d17aa560ba2..1b10fcc6a58ddeb660c93817b9972d0ef4783441 100644 (file)
--- a/drivers/net/tap.c
+++ b/drivers/net/tap.c
@@ -517,6 +517,10 @@ static int tap_open(struct inode *inode, struct file *file)
                                             &tap_proto, 0);
        if (!q)
                goto err;
+       if (skb_array_init(&q->skb_array, tap->dev->tx_queue_len, GFP_KERNEL)) {
+               sk_free(&q->sk);
+               goto err;
+       }
 
        RCU_INIT_POINTER(q->sock.wq, &q->wq);
        init_waitqueue_head(&q->wq.wait);
@@ -540,22 +544,18 @@ static int tap_open(struct inode *inode, struct file *file)
        if ((tap->dev->features & NETIF_F_HIGHDMA) && (tap->dev->features & NETIF_F_SG))
                sock_set_flag(&q->sk, SOCK_ZEROCOPY);
 
-       err = -ENOMEM;
-       if (skb_array_init(&q->skb_array, tap->dev->tx_queue_len, GFP_KERNEL))
-               goto err_array;
-
        err = tap_set_queue(tap, file, q);
-       if (err)
-               goto err_queue;
+       if (err) {
+               /* tap_sock_destruct() will take care of freeing skb_array */
+               goto err_put;
+       }
 
        dev_put(tap->dev);
 
        rtnl_unlock();
        return err;
 
-err_queue:
-       skb_array_cleanup(&q->skb_array);
-err_array:
+err_put:
        sock_put(&q->sk);
 err:
        if (tap)
@@ -1249,8 +1249,8 @@ static int tap_list_add(dev_t major, const char *device_name)
        return 0;
 }
 
-int tap_create_cdev(struct cdev *tap_cdev,
-                   dev_t *tap_major, const char *device_name)
+int tap_create_cdev(struct cdev *tap_cdev, dev_t *tap_major,
+                   const char *device_name, struct module *module)
 {
        int err;
 
@@ -1259,6 +1259,7 @@ int tap_create_cdev(struct cdev *tap_cdev,
                goto out1;
 
        cdev_init(tap_cdev, &tap_fops);
+       tap_cdev->owner = module;
        err = cdev_add(tap_cdev, *tap_major, TAP_NUM_DEVS);
        if (err)
                goto out2;