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From:   Al Viro <viro@ZenIV.linux.org.uk>
To:     netdev@vger.kernel.org
Cc:     "David S. Miller" <davem@davemloft.net>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        linux-kernel@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
        Al Viro <viro@zeniv.linux.org.uk>
Subject: [PATCH 07/10] lift handling of SIOCIW... out of dev_ioctl()
Date:   Thu, 18 Jan 2018 19:37:52 +0000
Message-Id: <20180118193755.19997-7-viro@ZenIV.linux.org.uk>
In-Reply-To: <20180118193755.19997-1-viro@ZenIV.linux.org.uk>
References: <20180118193156.GC13338@ZenIV.linux.org.uk>
 <20180118193755.19997-1-viro@ZenIV.linux.org.uk>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 include/net/wext.h       |  4 ++--
 net/core/dev_ioctl.c     | 18 ------------------
 net/socket.c             |  2 +-
 net/wireless/wext-core.c | 13 +++++++++----
 4 files changed, 12 insertions(+), 25 deletions(-)

diff --git a/include/net/wext.h b/include/net/wext.h
index e51f067fdb3a..aa192a670304 100644
--- a/include/net/wext.h
+++ b/include/net/wext.h
@@ -7,7 +7,7 @@
 struct net;
 
 #ifdef CONFIG_WEXT_CORE
-int wext_handle_ioctl(struct net *net, struct iwreq *iwr, unsigned int cmd,
+int wext_handle_ioctl(struct net *net, unsigned int cmd,
 		      void __user *arg);
 int compat_wext_handle_ioctl(struct net *net, unsigned int cmd,
 			     unsigned long arg);
@@ -15,7 +15,7 @@ int compat_wext_handle_ioctl(struct net *net, unsigned int cmd,
 struct iw_statistics *get_wireless_stats(struct net_device *dev);
 int call_commit_handler(struct net_device *dev);
 #else
-static inline int wext_handle_ioctl(struct net *net, struct iwreq *iwr, unsigned int cmd,
+static inline int wext_handle_ioctl(struct net *net, unsigned int cmd,
 				    void __user *arg)
 {
 	return -EINVAL;
diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c
index 5cdec23dd28e..d262f159f9fd 100644
--- a/net/core/dev_ioctl.c
+++ b/net/core/dev_ioctl.c
@@ -411,24 +411,6 @@ 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;
-
-		iwr.ifr_name[sizeof(iwr.ifr_name) - 1] = 0;
-
-		return wext_handle_ioctl(net, &iwr, cmd, arg);
-	}
-
 	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
 		return -EFAULT;
 
diff --git a/net/socket.c b/net/socket.c
index 6d29ebce93dd..d0e24f6ec1a9 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1005,7 +1005,7 @@ static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 	} else
 #ifdef CONFIG_WEXT_CORE
 	if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) {
-		err = dev_ioctl(net, cmd, argp);
+		err = wext_handle_ioctl(net, cmd, argp);
 	} else
 #endif
 		switch (cmd) {
diff --git a/net/wireless/wext-core.c b/net/wireless/wext-core.c
index 6cdb054484d6..9efbfc753347 100644
--- a/net/wireless/wext-core.c
+++ b/net/wireless/wext-core.c
@@ -1035,18 +1035,23 @@ static int ioctl_standard_call(struct net_device *	dev,
 }
 
 
-int wext_handle_ioctl(struct net *net, struct iwreq *iwr, unsigned int cmd,
-		      void __user *arg)
+int wext_handle_ioctl(struct net *net, unsigned int cmd, void __user *arg)
 {
 	struct iw_request_info info = { .cmd = cmd, .flags = 0 };
+	struct iwreq iwr;
 	int ret;
 
-	ret = wext_ioctl_dispatch(net, iwr, cmd, &info,
+	if (copy_from_user(&iwr, arg, sizeof(iwr)))
+		return -EFAULT;
+
+	iwr.ifr_name[sizeof(iwr.ifr_name) - 1] = 0;
+
+	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, iwr, sizeof(struct iwreq)))
+	    copy_to_user(arg, &iwr, sizeof(struct iwreq)))
 		return -EFAULT;
 
 	return ret;
-- 
2.11.0