drivers/isdn: 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, 3 insertions, 7 deletions

diff --git a/drivers/isdn/pcbit/drv.c b/drivers/isdn/pcbit/drv.c
index 123c1d6c43b4..1507d2e83fbb 100644
--- a/drivers/isdn/pcbit/drv.c
+++ b/drivers/isdn/pcbit/drv.c
@@ -411,14 +411,10 @@ static int pcbit_writecmd(const u_char __user *buf, int len, int driver, int cha
 			return -EINVAL;
 		}
 
-		cbuf = kmalloc(len, GFP_KERNEL);
-		if (!cbuf)
-			return -ENOMEM;
+		cbuf = memdup_user(buf, len);
+		if (IS_ERR(cbuf))
+			return PTR_ERR(cbuf);
 
-		if (copy_from_user(cbuf, buf, len)) {
-			kfree(cbuf);
-			return -EFAULT;
-		}
 		memcpy_toio(dev->sh_mem, cbuf, len);
 		kfree(cbuf);
 		return len;