May 27 2010

drivers/message/i2o/i2o_config.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/message/i2o/i2o_config.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)
 
diff --git a/drivers/message/i2o/i2o_config.c b/drivers/message/i2o/i2o_config.c
index d33693c..c4b117f 100644
--- a/drivers/message/i2o/i2o_config.c
+++ b/drivers/message/i2o/i2o_config.c
@@ -186,14 +186,9 @@ static int i2o_cfg_parms(unsigned long arg, unsigned int type)
 	if (!dev)
 		return -ENXIO;
 
-	ops = kmalloc(kcmd.oplen, GFP_KERNEL);
-	if (!ops)
-		return -ENOMEM;
-
-	if (copy_from_user(ops, kcmd.opbuf, kcmd.oplen)) {
-		kfree(ops);
-		return -EFAULT;
-	}
+	ops = memdup_user(kcmd.opbuf, kcmd.oplen);
+	if (IS_ERR(ops))
+		return PTR_ERR(ops);
 
 	/*
 	 * It's possible to have a _very_ large table

qlambert