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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/telephony/ixj.c | 15 ++++-----------
1 file changed, 4 insertions(+), 11 deletions(-)

diff --git a/drivers/telephony/ixj.c b/drivers/telephony/ixj.c
index e89304c..b53deee 100644
--- a/drivers/telephony/ixj.c
+++ b/drivers/telephony/ixj.c
@@ -5879,20 +5879,13 @@ out:
static int ixj_build_filter_cadence(IXJ *j, IXJ_FILTER_CADENCE __user * cp)
{
IXJ_FILTER_CADENCE *lcp;
- lcp = kmalloc(sizeof(IXJ_FILTER_CADENCE), GFP_KERNEL);
- if (lcp == NULL) {
+ lcp = memdup_user(cp, sizeof(IXJ_FILTER_CADENCE));
+ if (IS_ERR(lcp)) {
if(ixjdebug & 0x0001) {
- printk(KERN_INFO "Could not allocate memory for cadence\n");
+ printk(KERN_INFO "Could not allocate memory for cadence or could not copy cadence to kernel\n");
}
- return -ENOMEM;
+ return PTR_ERR(lcp);
}
- if (copy_from_user(lcp, cp, sizeof(IXJ_FILTER_CADENCE))) {
- if(ixjdebug & 0x0001) {
- printk(KERN_INFO "Could not copy cadence to kernel\n");
- }
- kfree(lcp);
- return -EFAULT;
- }
if (lcp->filter > 5) {
if(ixjdebug & 0x0001) {
printk(KERN_INFO "Cadence out of range\n");
--
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Prev: [PATCH 22/27] net/dccp: Use memdup_user
Next: [PATCH 21/27] drivers/ide: Use memdup_user