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From: Julia Lawall on 22 May 2010 04:30
From: Julia Lawall <julia(a)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/)

// <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(a)diku.dk>

---
drivers/ieee1394/video1394.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/ieee1394/video1394.c b/drivers/ieee1394/video1394.c
index a42bd68..a77483b 100644
--- a/drivers/ieee1394/video1394.c
+++ b/drivers/ieee1394/video1394.c
@@ -1045,14 +1045,9 @@ static long video1394_ioctl(struct file *file,
if (get_user(qv, &p->packet_sizes))
return -EFAULT;

- psizes = kmalloc(buf_size, GFP_KERNEL);
- if (!psizes)
- return -ENOMEM;
-
- if (copy_from_user(psizes, qv, buf_size)) {
- kfree(psizes);
- return -EFAULT;
- }
+ psizes = memdup_user(qv, buf_size);
+ if (IS_ERR(psizes))
+ return PTR_ERR(psizes);
}

spin_lock_irqsave(&d->lock,flags);
--
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Prev: [PATCH 15/27] drivers/mtd: Use memdup_user
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