[PATCH 21/27] drivers/ide: Use memdup_user

From: Julia Lawall
Date: Sat May 22 2010 - 04:25:21 EST


From: Julia Lawall <julia@xxxxxxx>

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@xxxxxxx>

---
drivers/ide/ide-taskfile.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index 67fb735..34b9872 100644
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -480,13 +480,9 @@ int ide_taskfile_ioctl(ide_drive_t *drive, unsigned long arg)
u16 nsect = 0;
char __user *buf = (char __user *)arg;

- req_task = kzalloc(tasksize, GFP_KERNEL);
- if (req_task == NULL)
- return -ENOMEM;
- if (copy_from_user(req_task, buf, tasksize)) {
- kfree(req_task);
- return -EFAULT;
- }
+ req_task = memdup_user(buf, tasksize);
+ if (IS_ERR(req_task))
+ return PTR_ERR(req_task);

taskout = req_task->out_size;
taskin = req_task->in_size;
--
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