separate SIOCGIFCONF from the rest of dev_ioctl()

index 9c23bd2efb56..84428fd0c999 100644
@@ -2729,7 +2729,8 @@ static inline bool dev_validate_header(const struct net_device *dev,
 	return false;
 }
 
-typedef int gifconf_func_t(struct net_device * dev, char __user * bufptr, int len);
+typedef int gifconf_func_t(struct net_device * dev, char __user * bufptr,
+			   int len, int size);
 int register_gifconf(unsigned int family, gifconf_func_t *gifconf);
 static inline int unregister_gifconf(unsigned int family)
 {

@@ -3278,6 +3279,7 @@ void netdev_rx_handler_unregister(struct net_device *dev);
 
 bool dev_valid_name(const char *name);
 int dev_ioctl(struct net *net, unsigned int cmd, void __user *);
+int dev_ifconf(struct net *net, struct ifconf *, int);
 int dev_ethtool(struct net *net, struct ifreq *);
 unsigned int dev_get_flags(const struct net_device *);
 int __dev_change_flags(struct net_device *, unsigned int flags);

index b94b1d293506..b98d1860b29a 100644
@@ -64,9 +64,8 @@ EXPORT_SYMBOL(register_gifconf);
  *	Thus we will need a 'compatibility mode'.
  */
 
-static int dev_ifconf(struct net *net, char __user *arg)
+int dev_ifconf(struct net *net, struct ifconf *ifc, int size)
 {
-	struct ifconf ifc;
 	struct net_device *dev;
 	char __user *pos;
 	int len;

@@ -77,11 +76,8 @@ static int dev_ifconf(struct net *net, char __user *arg)
 	 *	Fetch the caller's info block.
 	 */
 
-	if (copy_from_user(&ifc, arg, sizeof(struct ifconf)))
-		return -EFAULT;
-
-	pos = ifc.ifc_buf;
-	len = ifc.ifc_len;
+	pos = ifc->ifc_buf;
+	len = ifc->ifc_len;
 
 	/*
 	 *	Loop over the interfaces, and write an info block for each.

@@ -93,10 +89,10 @@ static int dev_ifconf(struct net *net, char __user *arg)
 			if (gifconf_list[i]) {
 				int done;
 				if (!pos)
-					done = gifconf_list[i](dev, NULL, 0);
+					done = gifconf_list[i](dev, NULL, 0, size);
 				else
 					done = gifconf_list[i](dev, pos + total,
-							       len - total);
+							       len - total, size);
 				if (done < 0)
 					return -EFAULT;
 				total += done;

@@ -107,12 +103,12 @@ static int dev_ifconf(struct net *net, char __user *arg)
 	/*
 	 *	All done.  Write the updated control block back to the caller.
 	 */
-	ifc.ifc_len = total;
+	ifc->ifc_len = total;
 
 	/*
 	 * 	Both BSD and Solaris return 0 here, so we do too.
 	 */
-	return copy_to_user(arg, &ifc, sizeof(struct ifconf)) ? -EFAULT : 0;
+	return 0;
 }
 
 /*

@@ -396,17 +392,6 @@ int dev_ioctl(struct net *net, unsigned int cmd, void __user *arg)
 	int ret;
 	char *colon;
 
-	/* One special case: SIOCGIFCONF takes ifconf argument
-	   and requires shared lock, because it sleeps writing
-	   to user space.
-	 */
-
-	if (cmd == SIOCGIFCONF) {
-		rtnl_lock();
-		ret = dev_ifconf(net, (char __user *) arg);
-		rtnl_unlock();
-		return ret;
-	}
 	if (cmd == SIOCGIFNAME)
 		return dev_ifname(net, (struct ifreq __user *)arg);
 

index df14815a3b8c..8f4621591556 100644
@@ -1160,22 +1160,25 @@ int devinet_ioctl(struct net *net, unsigned int cmd, void __user *arg)
 	goto out;
 }
 
-static int inet_gifconf(struct net_device *dev, char __user *buf, int len)
+static int inet_gifconf(struct net_device *dev, char __user *buf, int len, int size)
 {
 	struct in_device *in_dev = __in_dev_get_rtnl(dev);
 	struct in_ifaddr *ifa;
 	struct ifreq ifr;
 	int done = 0;
 
+	if (WARN_ON(size > sizeof(struct ifreq)))
+		goto out;
+
 	if (!in_dev)
 		goto out;
 
 	for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) {
 		if (!buf) {
-			done += sizeof(ifr);
+			done += size;
 			continue;
 		}
-		if (len < (int) sizeof(ifr))
+		if (len < size)
 			break;
 		memset(&ifr, 0, sizeof(struct ifreq));
 		strcpy(ifr.ifr_name, ifa->ifa_label);

@@ -1184,13 +1187,12 @@ static int inet_gifconf(struct net_device *dev, char __user *buf, int len)
 		(*(struct sockaddr_in *)&ifr.ifr_addr).sin_addr.s_addr =
 								ifa->ifa_local;
 
-		if (copy_to_user(buf, &ifr, sizeof(struct ifreq))) {
+		if (copy_to_user(buf + done, &ifr, size)) {
 			done = -EFAULT;
 			break;
 		}
-		buf  += sizeof(struct ifreq);
-		len  -= sizeof(struct ifreq);
-		done += sizeof(struct ifreq);
+		len  -= size;
+		done += size;
 	}
 out:
 	return done;

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