1 files changed, 37 insertions, 1 deletions

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 7b816a032957..5b5d87585d91 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -67,9 +67,42 @@
 #include <asm/system.h>
 #include <asm/uaccess.h>
 
+/* Uncomment to enable debugging */
+/* #define TUN_DEBUG 1 */
+
 #ifdef TUN_DEBUG
 static int debug;
+
+#define DBG  if(tun->debug)printk
+#define DBG1 if(debug==2)printk
+#else
+#define DBG( a... )
+#define DBG1( a... )
+#endif
+
+struct tun_struct {
+        struct list_head        list;
+        unsigned long           flags;
+        int                     attached;
+        uid_t                   owner;
+        gid_t                   group;
+
+        wait_queue_head_t       read_wait;
+        struct sk_buff_head     readq;
+
+        struct net_device       *dev;
+
+        struct fasync_struct    *fasync;
+
+        unsigned long if_flags;
+        u8 dev_addr[ETH_ALEN];
+        u32 chr_filter[2];
+        u32 net_filter[2];
+
+#ifdef TUN_DEBUG
+        int debug;
 #endif
+};
 
 /* Network device part of the driver */
 
@@ -253,8 +286,11 @@ static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv,
                         return -EFAULT;
         }
 
-        if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV)
+        if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
                 align = NET_IP_ALIGN;
+                if (unlikely(len < ETH_HLEN))
+                        return -EINVAL;
+        }
 
         if (!(skb = alloc_skb(len + align, GFP_KERNEL))) {
                 tun->dev->stats.rx_dropped++;