drivers/char/applicom.c: use memdup_user

Author: Julia Lawall <julia@diku.dk>

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/)

// 
@@
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
-    ...+>
-  }
// 

Signed-off-by: Julia Lawall 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

---
 drivers/char/applicom.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)
 
diff --git a/drivers/char/applicom.c b/drivers/char/applicom.c
index 63313a3..f4ae0e0 100644
--- a/drivers/char/applicom.c
+++ b/drivers/char/applicom.c
@@ -703,14 +703,9 @@ static long ac_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	/* In general, the device is only openable by root anyway, so we're not
 	   particularly concerned that bogus ioctls can flood the console. */
 
-	adgl = kmalloc(sizeof(struct st_ram_io), GFP_KERNEL);
-	if (!adgl)
-		return -ENOMEM;
-
-	if (copy_from_user(adgl, argp, sizeof(struct st_ram_io))) {
-		kfree(adgl);
-		return -EFAULT;
-	}
+	adgl = memdup_user(argp, sizeof(struct st_ram_io));
+	if (IS_ERR(adgl))
+		return PTR_ERR(adgl);
 
 	lock_kernel();	
 	IndexCard = adgl->num_card-1;

drivers/char/applicom.c: use memdup_user

qlambert

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