[PATCH 7/10] drivers/hid: introduce missing kfree

[PATCH 7/10] drivers/hid: introduce missing kfree

[Julia Lawall]

From: Julia Lawall <julia@diku.dk>

Error handling code following a kzalloc should free the allocated data.

The semantic match that finds the problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r exists@
local idexpression x;
statement S;
expression E;
identifier f,f1,l;
position p1,p2;
expression *ptr != NULL;
@@

x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
...
if (x == NULL) S
<... when != x
     when != if (...) { <+...x...+> }
(
x->f1 = E
|
 (x->f1 == NULL || ...)
|
 f(...,x->f1,...)
)
...>
(
 return \(0\|<+...x...+>\|ptr\);
|
 return@p2 ...;
)

@script:python@
p1 << r.p1;
p2 << r.p2;
@@

print "* file: %s kmalloc %s return %s" % (p1[0].file,p1[0].line,p2[0].line)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
---
 drivers/hid/hid-debug.c             |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/hid/hid-debug.c b/drivers/hid/hid-debug.c
index 3e425f7..6abd036 100644
--- a/drivers/hid/hid-debug.c
+++ b/drivers/hid/hid-debug.c
@@ -928,6 +928,7 @@ static int hid_debug_events_open(struct inode *inode, struct file *file)
 
 	if (!(list->hid_debug_buf = kzalloc(sizeof(char) * HID_DEBUG_BUFSIZE, GFP_KERNEL))) {
 		err = -ENOMEM;
+		kfree(list);
 		goto out;
 	}
 	list->hdev = (struct hid_device *) inode->i_private;

Re: [PATCH 7/10] drivers/hid: introduce missing kfree

[Jiri Kosina]

On Sat, 1 Aug 2009, Julia Lawall wrote:

> From: Julia Lawall <julia@diku.dk>
> 
> Error handling code following a kzalloc should free the allocated data.
> 
> The semantic match that finds the problem is as follows:
> (http://www.emn.fr/x-info/coccinelle/)
> 
> // <smpl>
> @r exists@
> local idexpression x;
> statement S;
> expression E;
> identifier f,f1,l;
> position p1,p2;
> expression *ptr != NULL;
> @@
> 
> x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
> ...
> if (x == NULL) S
> <... when != x
>      when != if (...) { <+...x...+> }
> (
> x->f1 = E
> |
>  (x->f1 == NULL || ...)
> |
>  f(...,x->f1,...)
> )
> ...>
> (
>  return \(0\|<+...x...+>\|ptr\);
> |
>  return@p2 ...;
> )
> 
> @script:python@
> p1 << r.p1;
> p2 << r.p2;
> @@
> 
> print "* file: %s kmalloc %s return %s" % (p1[0].file,p1[0].line,p2[0].line)
> // </smpl>
> 
> Signed-off-by: Julia Lawall <julia@diku.dk>
> ---
>  drivers/hid/hid-debug.c             |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/hid/hid-debug.c b/drivers/hid/hid-debug.c
> index 3e425f7..6abd036 100644
> --- a/drivers/hid/hid-debug.c
> +++ b/drivers/hid/hid-debug.c
> @@ -928,6 +928,7 @@ static int hid_debug_events_open(struct inode *inode, struct file *file)
>  
>  	if (!(list->hid_debug_buf = kzalloc(sizeof(char) * HID_DEBUG_BUFSIZE, GFP_KERNEL))) {
>  		err = -ENOMEM;
> +		kfree(list);
>  		goto out;
>  	}
>  	list->hdev = (struct hid_device *) inode->i_private;
> 

Applied, thanks a lot Julia.

-- 
Jiri Kosina
SUSE Labs