From: Ivan Safonov <insafonov@gmail.com>
Date: Sat, 13 Feb 2021 12:05:28 +0000 (+0300)
Subject: staging:wlan-ng: use memdup_user instead of kmalloc/copy_from_user
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=bc4bf94cc2aed9192184782dbb9f884c5d6b9e82;p=linux.git

staging:wlan-ng: use memdup_user instead of kmalloc/copy_from_user

memdup_user() is shorter and safer equivalent
of kmalloc/copy_from_user pair.

Signed-off-by: Ivan Safonov <insafonov@gmail.com>
Link: https://lore.kernel.org/r/20210213120527.451531-1-insafonov@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/staging/wlan-ng/p80211netdev.c b/drivers/staging/wlan-ng/p80211netdev.c
index a15abb2c8f54d..6f9666dc02779 100644
--- a/drivers/staging/wlan-ng/p80211netdev.c
+++ b/drivers/staging/wlan-ng/p80211netdev.c
@@ -569,24 +569,22 @@ static int p80211knetdev_do_ioctl(struct net_device *dev,
 		goto bail;
 	}
 
-	/* Allocate a buf of size req->len */
-	msgbuf = kmalloc(req->len, GFP_KERNEL);
-	if (msgbuf) {
-		if (copy_from_user(msgbuf, (void __user *)req->data, req->len))
-			result = -EFAULT;
-		else
-			result = p80211req_dorequest(wlandev, msgbuf);
+	msgbuf = memdup_user(req->data, req->len);
+	if (IS_ERR(msgbuf)) {
+		result = PTR_ERR(msgbuf);
+		goto bail;
+	}
 
-		if (result == 0) {
-			if (copy_to_user
-			    ((void __user *)req->data, msgbuf, req->len)) {
-				result = -EFAULT;
-			}
+	result = p80211req_dorequest(wlandev, msgbuf);
+
+	if (result == 0) {
+		if (copy_to_user
+		    ((void __user *)req->data, msgbuf, req->len)) {
+			result = -EFAULT;
 		}
-		kfree(msgbuf);
-	} else {
-		result = -ENOMEM;
 	}
+	kfree(msgbuf);
+
 bail:
 	/* If allocate,copyfrom or copyto fails, return errno */
 	return result;