drivers/net/wan: Use memdup_user

Use memdup_user when user data is immediately copied into the
allocated region.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression from,to,size,flag;
position p;
identifier l1,l2;
@@

-  to = \(kmalloc@p\|kzalloc@p\)(size,flag);
+  to = memdup_user(from,size);
   if (
-      to==NULL
+      IS_ERR(to)
                 || ...) {
   <+... when != goto l1;
-  -ENOMEM
+  PTR_ERR(to)
   ...+>
   }
-  if (copy_from_user(to, from, size) != 0) {
-    <+... when != goto l2;
-    -EFAULT
-    ...+>
-  }
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 10 deletions

diff --git a/drivers/net/wan/farsync.c b/drivers/net/wan/farsync.c
index e087b9a6daaa..43b77271532b 100644
--- a/drivers/net/wan/farsync.c
+++ b/drivers/net/wan/farsync.c
@@ -2038,16 +2038,10 @@ fst_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 
                 /* Now copy the data to the card. */
 
-                buf = kmalloc(wrthdr.size, GFP_KERNEL);
-                if (!buf)
-                        return -ENOMEM;
-
-                if (copy_from_user(buf,
-                                   ifr->ifr_data + sizeof (struct fstioc_write),
-                                   wrthdr.size)) {
-                        kfree(buf);
-                        return -EFAULT;
-                }
+                buf = memdup_user(ifr->ifr_data + sizeof(struct fstioc_write),
+                                  wrthdr.size);
+                if (IS_ERR(buf))
+                        return PTR_ERR(buf);
 
                 memcpy_toio(card->mem + wrthdr.offset, buf, wrthdr.size);
                 kfree(buf);