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, 3 insertions, 7 deletions

diff --git a/drivers/media/dvb/dvb-core/dvb_demux.c b/drivers/media/dvb/dvb-core/dvb_demux.c
index 977ddba3e235..4a88a3e4db2b 100644
--- a/drivers/media/dvb/dvb-core/dvb_demux.c
+++ b/drivers/media/dvb/dvb-core/dvb_demux.c
@@ -1130,13 +1130,9 @@ static int dvbdmx_write(struct dmx_demux *demux, const char __user *buf, size_t
 	if ((!demux->frontend) || (demux->frontend->source != DMX_MEMORY_FE))
 		return -EINVAL;
 
-	p = kmalloc(count, GFP_USER);
-	if (!p)
-		return -ENOMEM;
-	if (copy_from_user(p, buf, count)) {
-		kfree(p);
-		return -EFAULT;
-	}
+	p = memdup_user(buf, count);
+	if (IS_ERR(p))
+		return PTR_ERR(p);
 	if (mutex_lock_interruptible(&dvbdemux->mutex)) {
 		kfree(p);
 		return -ERESTARTSYS;