drivers/isdn: Use memdup_user

Author: Julia Lawall <julia@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/)

// 
@@
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
-    ...+>
-  }
// 

Signed-off-by: Julia Lawall 
Signed-off-by: David S. Miller 
---
 drivers/isdn/i4l/isdn_ppp.c | 11 +++--------
 drivers/isdn/pcbit/drv.c    | 10 +++-------
 drivers/isdn/sc/ioctl.c     | 23 ++++++-----------------
 3 files changed, 12 insertions(+), 32 deletions(-)
 
diff --git a/drivers/isdn/i4l/isdn_ppp.c b/drivers/isdn/i4l/isdn_ppp.c
index f37b8f6..8c46bae 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 123c1d6..1507d2e 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 1081091..43c5dc35 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",
BtrLinux
Privacy Overview

This website uses cookies so that we can provide you with the best user experience possible. Cookie information is stored in your browser and performs functions such as recognising you when you return to our website and helping our team to understand which sections of the website you find most interesting and useful.