Merge tag 'mac80211-for-davem-2017-06-16' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211

Johannes Berg says:

====================
Here's just the fix for that ancient bug:
 * remove wext calling ndo_do_ioctl, since nobody needs
   that now and it makes the type change easier
 * use struct iwreq instead of struct ifreq almost everywhere
   in wireless extensions code
 * copy only struct iwreq from userspace in dev_ioctl for the
   wireless extensions, since it's smaller than struct ifreq
====================

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

2 files changed, 25 insertions, 16 deletions

diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c
index b94b1d293506..27fad31784a8 100644
--- a/net/core/dev_ioctl.c
+++ b/net/core/dev_ioctl.c
@@ -410,6 +410,22 @@ int dev_ioctl(struct net *net, unsigned int cmd, void __user *arg)
 	if (cmd == SIOCGIFNAME)
 		return dev_ifname(net, (struct ifreq __user *)arg);
 
+	/*
+	 * Take care of Wireless Extensions. Unfortunately struct iwreq
+	 * isn't a proper subset of struct ifreq (it's 8 byte shorter)
+	 * so we need to treat it specially, otherwise applications may
+	 * fault if the struct they're passing happens to land at the
+	 * end of a mapped page.
+	 */
+	if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) {
+		struct iwreq iwr;
+
+		if (copy_from_user(&iwr, arg, sizeof(iwr)))
+			return -EFAULT;
+
+		return wext_handle_ioctl(net, &iwr, cmd, arg);
+	}
+
 	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
 		return -EFAULT;
 
@@ -559,9 +575,6 @@ int dev_ioctl(struct net *net, unsigned int cmd, void __user *arg)
 				ret = -EFAULT;
 			return ret;
 		}
-		/* Take care of Wireless Extensions */
-		if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST)
-			return wext_handle_ioctl(net, &ifr, cmd, arg);
 		return -ENOTTY;
 	}
 }
diff --git a/net/wireless/wext-core.c b/net/wireless/wext-core.c
index 1a4db6790e20..6cdb054484d6 100644
--- a/net/wireless/wext-core.c
+++ b/net/wireless/wext-core.c
@@ -914,13 +914,12 @@ int call_commit_handler(struct net_device *dev)
  * Main IOCTl dispatcher.
  * Check the type of IOCTL and call the appropriate wrapper...
  */
-static int wireless_process_ioctl(struct net *net, struct ifreq *ifr,
+static int wireless_process_ioctl(struct net *net, struct iwreq *iwr,
 				  unsigned int cmd,
 				  struct iw_request_info *info,
 				  wext_ioctl_func standard,
 				  wext_ioctl_func private)
 {
-	struct iwreq *iwr = (struct iwreq *) ifr;
 	struct net_device *dev;
 	iw_handler	handler;
 
@@ -928,7 +927,7 @@ static int wireless_process_ioctl(struct net *net, struct ifreq *ifr,
 	 * The copy_to/from_user() of ifr is also dealt with in there */
 
 	/* Make sure the device exist */
-	if ((dev = __dev_get_by_name(net, ifr->ifr_name)) == NULL)
+	if ((dev = __dev_get_by_name(net, iwr->ifr_name)) == NULL)
 		return -ENODEV;
 
 	/* A bunch of special cases, then the generic case...
@@ -957,9 +956,6 @@ static int wireless_process_ioctl(struct net *net, struct ifreq *ifr,
 		else if (private)
 			return private(dev, iwr, cmd, info, handler);
 	}
-	/* Old driver API : call driver ioctl handler */
-	if (dev->netdev_ops->ndo_do_ioctl)
-		return dev->netdev_ops->ndo_do_ioctl(dev, ifr, cmd);
 	return -EOPNOTSUPP;
 }
 
@@ -977,7 +973,7 @@ static int wext_permission_check(unsigned int cmd)
 }
 
 /* entry point from dev ioctl */
-static int wext_ioctl_dispatch(struct net *net, struct ifreq *ifr,
+static int wext_ioctl_dispatch(struct net *net, struct iwreq *iwr,
 			       unsigned int cmd, struct iw_request_info *info,
 			       wext_ioctl_func standard,
 			       wext_ioctl_func private)
@@ -987,9 +983,9 @@ static int wext_ioctl_dispatch(struct net *net, struct ifreq *ifr,
 	if (ret)
 		return ret;
 
-	dev_load(net, ifr->ifr_name);
+	dev_load(net, iwr->ifr_name);
 	rtnl_lock();
-	ret = wireless_process_ioctl(net, ifr, cmd, info, standard, private);
+	ret = wireless_process_ioctl(net, iwr, cmd, info, standard, private);
 	rtnl_unlock();
 
 	return ret;
@@ -1039,18 +1035,18 @@ static int ioctl_standard_call(struct net_device *	dev,
 }
 
 
-int wext_handle_ioctl(struct net *net, struct ifreq *ifr, unsigned int cmd,
+int wext_handle_ioctl(struct net *net, struct iwreq *iwr, unsigned int cmd,
 		      void __user *arg)
 {
 	struct iw_request_info info = { .cmd = cmd, .flags = 0 };
 	int ret;
 
-	ret = wext_ioctl_dispatch(net, ifr, cmd, &info,
+	ret = wext_ioctl_dispatch(net, iwr, cmd, &info,
 				  ioctl_standard_call,
 				  ioctl_private_call);
 	if (ret >= 0 &&
 	    IW_IS_GET(cmd) &&
-	    copy_to_user(arg, ifr, sizeof(struct iwreq)))
+	    copy_to_user(arg, iwr, sizeof(struct iwreq)))
 		return -EFAULT;
 
 	return ret;
@@ -1107,7 +1103,7 @@ int compat_wext_handle_ioctl(struct net *net, unsigned int cmd,
 	info.cmd = cmd;
 	info.flags = IW_REQUEST_FLAG_COMPAT;
 
-	ret = wext_ioctl_dispatch(net, (struct ifreq *) &iwr, cmd, &info,
+	ret = wext_ioctl_dispatch(net, &iwr, cmd, &info,
 				  compat_standard_call,
 				  compat_private_call);