dev_ioctl: pass SIOCDEVPRIVATE data separately

The compat handlers for SIOCDEVPRIVATE are incorrect for any driver that
passes data as part of struct ifreq rather than as an ifr_data pointer, or
that passes data back this way, since the compat_ifr_data_ioctl() helper
overwrites the ifr_data pointer and does not copy anything back out.

Since all drivers using devprivate commands are now converted to the
new .ndo_siocdevprivate callback, fix this by adding the missing piece
and passing the pointer separately the whole way.

This further unifies the native and compat logic for socket ioctls,
as the new code now passes the correct pointer as well as the correct
data for both native and compat ioctls.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 13 insertions, 42 deletions

diff --git a/net/socket.c b/net/socket.c
index 84de89c1ee9d..ddce6327633e 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1092,6 +1092,7 @@ static long sock_do_ioctl(struct net *net, struct socket *sock,
 	bool need_copyout;
 	int err;
 	void __user *argp = (void __user *)arg;
+	void __user *data;
 
 	err = sock->ops->ioctl(sock, cmd, arg);
 
@@ -1102,11 +1103,11 @@ static long sock_do_ioctl(struct net *net, struct socket *sock,
 	if (err != -ENOIOCTLCMD)
 		return err;
 
-	if (copy_from_user(&ifr, argp, sizeof(struct ifreq)))
+	if (get_user_ifreq(&ifr, &data, argp))
 		return -EFAULT;
-	err = dev_ioctl(net, cmd, &ifr, &need_copyout);
+	err = dev_ioctl(net, cmd, &ifr, data, &need_copyout);
 	if (!err && need_copyout)
-		if (copy_to_user(argp, &ifr, sizeof(struct ifreq)))
+		if (put_user_ifreq(&ifr, argp))
 			return -EFAULT;
 
 	return err;
@@ -1130,12 +1131,13 @@ static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 	net = sock_net(sk);
 	if (unlikely(cmd >= SIOCDEVPRIVATE && cmd <= (SIOCDEVPRIVATE + 15))) {
 		struct ifreq ifr;
+		void __user *data;
 		bool need_copyout;
-		if (copy_from_user(&ifr, argp, sizeof(struct ifreq)))
+		if (get_user_ifreq(&ifr, &data, argp))
 			return -EFAULT;
-		err = dev_ioctl(net, cmd, &ifr, &need_copyout);
+		err = dev_ioctl(net, cmd, &ifr, data, &need_copyout);
 		if (!err && need_copyout)
-			if (copy_to_user(argp, &ifr, sizeof(struct ifreq)))
+			if (put_user_ifreq(&ifr, argp))
 				return -EFAULT;
 	} else
 #ifdef CONFIG_WEXT_CORE
@@ -3186,7 +3188,7 @@ static int compat_siocwandev(struct net *net, struct compat_ifreq __user *uifr32
 	saved = ifr.ifr_settings.ifs_ifsu.raw_hdlc;
 	ifr.ifr_settings.ifs_ifsu.raw_hdlc = compat_ptr(uptr32);
 
-	err = dev_ioctl(net, SIOCWANDEV, &ifr, NULL);
+	err = dev_ioctl(net, SIOCWANDEV, &ifr, NULL, NULL);
 	if (!err) {
 		ifr.ifr_settings.ifs_ifsu.raw_hdlc = saved;
 		if (put_user_ifreq(&ifr, uifr32))
@@ -3200,42 +3202,13 @@ static int compat_ifr_data_ioctl(struct net *net, unsigned int cmd,
 				 struct compat_ifreq __user *u_ifreq32)
 {
 	struct ifreq ifreq;
-	u32 data32;
+	void __user *data;
 
-	if (copy_from_user(ifreq.ifr_name, u_ifreq32->ifr_name, IFNAMSIZ))
+	if (get_user_ifreq(&ifreq, &data, u_ifreq32))
 		return -EFAULT;
-	if (get_user(data32, &u_ifreq32->ifr_data))
-		return -EFAULT;
-	ifreq.ifr_data = compat_ptr(data32);
+	ifreq.ifr_data = data;
 
-	return dev_ioctl(net, cmd, &ifreq, NULL);
-}
-
-static int compat_ifreq_ioctl(struct net *net, struct socket *sock,
-			      unsigned int cmd,
-			      unsigned long arg,
-			      struct compat_ifreq __user *uifr32)
-{
-	struct ifreq ifr;
-	bool need_copyout;
-	int err;
-
-	err = sock->ops->ioctl(sock, cmd, arg);
-
-	/* If this ioctl is unknown try to hand it down
-	 * to the NIC driver.
-	 */
-	if (err != -ENOIOCTLCMD)
-		return err;
-
-	if (get_user_ifreq(&ifr, NULL, uifr32))
-		return -EFAULT;
-	err = dev_ioctl(net, cmd, &ifr, &need_copyout);
-	if (!err && need_copyout)
-		if (put_user_ifreq(&ifr, uifr32))
-			return -EFAULT;
-
-	return err;
+	return dev_ioctl(net, cmd, &ifreq, data, NULL);
 }
 
 /* Since old style bridge ioctl's endup using SIOCDEVPRIVATE
@@ -3337,8 +3310,6 @@ static int compat_sock_ioctl_trans(struct file *file, struct socket *sock,
 	case SIOCBONDRELEASE:
 	case SIOCBONDSETHWADDR:
 	case SIOCBONDCHANGEACTIVE:
-		return compat_ifreq_ioctl(net, sock, cmd, arg, argp);
-
 	case SIOCSARP:
 	case SIOCGARP:
 	case SIOCDARP: