drivers/isdn: Use memdup_user

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@diku.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 12 insertions, 32 deletions

diff --git a/drivers/isdn/i4l/isdn_ppp.c b/drivers/isdn/i4l/isdn_ppp.c
index f37b8f68d0aa..8c46baee621b 100644
--- a/drivers/isdn/i4l/isdn_ppp.c
+++ b/drivers/isdn/i4l/isdn_ppp.c
@@ -449,14 +449,9 @@ static int get_filter(void __user *arg, struct sock_filter **p)
 
         /* uprog.len is unsigned short, so no overflow here */
         len = uprog.len * sizeof(struct sock_filter);
-        code = kmalloc(len, GFP_KERNEL);
-        if (code == NULL)
-                return -ENOMEM;
-
-        if (copy_from_user(code, uprog.filter, len)) {
-                kfree(code);
-                return -EFAULT;
-        }
+        code = memdup_user(uprog.filter, len);
+        if (IS_ERR(code))
+                return PTR_ERR(code);
 
         err = sk_chk_filter(code, uprog.len);
         if (err) {
diff --git a/drivers/isdn/pcbit/drv.c b/drivers/isdn/pcbit/drv.c
index 123c1d6c43b4..1507d2e83fbb 100644
--- a/drivers/isdn/pcbit/drv.c
+++ b/drivers/isdn/pcbit/drv.c
@@ -411,14 +411,10 @@ static int pcbit_writecmd(const u_char __user *buf, int len, int driver, int cha
                         return -EINVAL;
                 }
 
-                cbuf = kmalloc(len, GFP_KERNEL);
-                if (!cbuf)
-                        return -ENOMEM;
+                cbuf = memdup_user(buf, len);
+                if (IS_ERR(cbuf))
+                        return PTR_ERR(cbuf);
 
-                if (copy_from_user(cbuf, buf, len)) {
-                        kfree(cbuf);
-                        return -EFAULT;
-                }
                 memcpy_toio(dev->sh_mem, cbuf, len);
                 kfree(cbuf);
                 return len;
diff --git a/drivers/isdn/sc/ioctl.c b/drivers/isdn/sc/ioctl.c
index 1081091bbfaf..43c5dc3516e5 100644
--- a/drivers/isdn/sc/ioctl.c
+++ b/drivers/isdn/sc/ioctl.c
@@ -215,19 +215,13 @@ int sc_ioctl(int card, scs_ioctl *data)
                 pr_debug("%s: DCBIOSETSPID: ioctl received\n",
                                 sc_adapter[card]->devicename);
 
-                spid = kmalloc(SCIOC_SPIDSIZE, GFP_KERNEL);
-                if(!spid) {
-                        kfree(rcvmsg);
-                        return -ENOMEM;
-                }
-
                 /*
                  * Get the spid from user space
                  */
-                if (copy_from_user(spid, data->dataptr, SCIOC_SPIDSIZE)) {
+                spid = memdup_user(data->dataptr, SCIOC_SPIDSIZE);
+                if (IS_ERR(spid)) {
                         kfree(rcvmsg);
-                        kfree(spid);
-                        return -EFAULT;
+                        return PTR_ERR(spid);
                 }
 
                 pr_debug("%s: SCIOCSETSPID: setting channel %d spid to %s\n", 
@@ -296,18 +290,13 @@ int sc_ioctl(int card, scs_ioctl *data)
                 pr_debug("%s: SCIOSETDN: ioctl received\n",
                                 sc_adapter[card]->devicename);
 
-                dn = kmalloc(SCIOC_DNSIZE, GFP_KERNEL);
-                if (!dn) {
-                        kfree(rcvmsg);
-                        return -ENOMEM;
-                }
                 /*
                  * Get the spid from user space
                  */
-                if (copy_from_user(dn, data->dataptr, SCIOC_DNSIZE)) {
+                dn = memdup_user(data->dataptr, SCIOC_DNSIZE);
+                if (IS_ERR(dn)) {
                         kfree(rcvmsg);
-                        kfree(dn);
-                        return -EFAULT;
+                        return PTR_ERR(dn);
                 }
 
                 pr_debug("%s: SCIOCSETDN: setting channel %d dn to %s\n",