Aug 24 2011

[S390] drivers/s390/block/dasd_ioctl.c: add missing kfree 

Author: Julia Lawall <julia@diku.dk>

Data is only used to temporarily hold information to be copied to the user
level, so it should be freed before leaving the function.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// 
@exists@
local idexpression x;
statement S,S1;
expression E;
identifier fl;
expression *ptr != NULL;
@@

x = \(kmalloc\|kzalloc\|kcalloc\)(...);
...
if (x == NULL) S
<... when != x
     when != if (...) { <+...kfree(x)...+> }
     when any
     when != true x == NULL
x->fl
...>
(
if (x == NULL) S1
|
if (...) { ... when != x
               when forall
(
 return \(0\|<+...x...+>\|ptr\);
|
* return ...;
)
}
)
// 

Signed-off-by: Julia Lawall 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky 

---
 drivers/s390/block/dasd_ioctl.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)
 
diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c
index eb4e034..f1a2016 100644
--- a/drivers/s390/block/dasd_ioctl.c
+++ b/drivers/s390/block/dasd_ioctl.c
@@ -249,6 +249,7 @@ static int dasd_ioctl_reset_profile(struct dasd_block *block)
 static int dasd_ioctl_read_profile(struct dasd_block *block, void __user *argp)
 {
 	struct dasd_profile_info_t *data;
+	int rc = 0;
 
 	data = kmalloc(sizeof(*data), GFP_KERNEL);
 	if (!data)
@@ -279,11 +280,14 @@ static int dasd_ioctl_read_profile(struct dasd_block *block, void __user *argp)
 		spin_unlock_bh(&block->profile.lock);
 	} else {
 		spin_unlock_bh(&block->profile.lock);
-		return -EIO;
+		rc = -EIO;
+		goto out;
 	}
 	if (copy_to_user(argp, data, sizeof(*data)))
-		return -EFAULT;
-	return 0;
+		rc = -EFAULT;
+out:
+	kfree(data);
+	return rc;
 }
 #else
 static int dasd_ioctl_reset_profile(struct dasd_block *block)

qlambert