Merge branch 'tun-cleanups'

Markus Elfring says:

====================
tun: Fine-tuning for update_filter()

A few update suggestions were taken into account
from static source code analysis.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

Author: davem330

drivers/net/tun.c

@@ -731,14 +731,9 @@ static int update_filter(struct tap_filter *filter, void __user *arg)
 	}
 
 	alen = ETH_ALEN * uf.count;
-	addr = kmalloc(alen, GFP_KERNEL);
-	if (!addr)
-		return -ENOMEM;
-
-	if (copy_from_user(addr, arg + sizeof(uf), alen)) {
-		err = -EFAULT;
-		goto done;
-	}
+	addr = memdup_user(arg + sizeof(uf), alen);
+	if (IS_ERR(addr))
+		return PTR_ERR(addr);
 
 	/* The filter is updated without holding any locks. Which is
 	 * perfectly safe. We disable it first and in the worst
@@ -758,7 +753,7 @@ static int update_filter(struct tap_filter *filter, void __user *arg)
 	for (; n < uf.count; n++) {
 		if (!is_multicast_ether_addr(addr[n].u)) {
 			err = 0; /* no filter */
-			goto done;
+			goto free_addr;
 		}
 		addr_hash_set(filter->mask, addr[n].u);
 	}
@@ -774,8 +769,7 @@ static int update_filter(struct tap_filter *filter, void __user *arg)
 
 	/* Return the number of exact filters */
 	err = nexact;
-
-done:
+free_addr:
 	kfree(addr);
 	return err;
 }