V4L/DVB: drivers/media: 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: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 4 insertions, 9 deletions

diff --git a/drivers/media/video/dabusb.c b/drivers/media/video/dabusb.c
index 0f505086774..5b176bd7afd 100644
--- a/drivers/media/video/dabusb.c
+++ b/drivers/media/video/dabusb.c
@@ -706,16 +706,11 @@ static long dabusb_ioctl (struct file *file, unsigned int cmd, unsigned long arg
 	switch (cmd) {
 
 	case IOCTL_DAB_BULK:
-		pbulk = kmalloc(sizeof (bulk_transfer_t), GFP_KERNEL);
+		pbulk = memdup_user((void __user *)arg,
+				    sizeof(bulk_transfer_t));
 
-		if (!pbulk) {
-			ret = -ENOMEM;
-			break;
-		}
-
-		if (copy_from_user (pbulk, (void __user *) arg, sizeof (bulk_transfer_t))) {
-			ret = -EFAULT;
-			kfree (pbulk);
+		if (IS_ERR(pbulk)) {
+			ret = PTR_ERR(pbulk);
 			break;
 		}