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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/net/wan/farsync.c | 14 ++++----------
1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/drivers/net/wan/farsync.c b/drivers/net/wan/farsync.c
index e087b9a..43b7727 100644
--- a/drivers/net/wan/farsync.c
+++ b/drivers/net/wan/farsync.c
@@ -2038,16 +2038,10 @@ fst_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)

/* Now copy the data to the card. */

- buf = kmalloc(wrthdr.size, GFP_KERNEL);
- if (!buf)
- return -ENOMEM;
-
- if (copy_from_user(buf,
- ifr->ifr_data + sizeof (struct fstioc_write),
- wrthdr.size)) {
- kfree(buf);
- return -EFAULT;
- }
+ buf = memdup_user(ifr->ifr_data + sizeof(struct fstioc_write),
+ wrthdr.size);
+ if (IS_ERR(buf))
+ return PTR_ERR(buf);

memcpy_toio(card->mem + wrthdr.offset, buf, wrthdr.size);
kfree(buf);
--
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Prev: [PATCH 21/27] drivers/ide: Use memdup_user
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