From: Stephen Hemminger <stephen@networkplumber.org>
Date: Mon, 24 Jun 2019 16:47:11 +0000 (-0700)
Subject: kni: fix copy_from_user failure handling
X-Git-Url: http://git.droids-corp.org/?p=dpdk.git;a=commitdiff_plain;h=21dde05a95bb301d485ac2c332a80271213e67c3

kni: fix copy_from_user failure handling

The correct thing to return if user gives a bad data
is to return -EFAULT. Logging is also discouraged because
it could be used as a DoS attack.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Ferruh Yigit <ferruh.yigit@intel.com>
---

diff --git a/kernel/linux/kni/kni_misc.c b/kernel/linux/kni/kni_misc.c
index b59cf24c21..be45f82340 100644
--- a/kernel/linux/kni/kni_misc.c
+++ b/kernel/linux/kni/kni_misc.c
@@ -301,11 +301,8 @@ kni_ioctl_create(struct net *net, uint32_t ioctl_num,
 		return -EINVAL;
 
 	/* Copy kni info from user space */
-	ret = copy_from_user(&dev_info, (void *)ioctl_param, sizeof(dev_info));
-	if (ret) {
-		pr_err("copy_from_user in kni_ioctl_create");
-		return -EIO;
-	}
+	if (copy_from_user(&dev_info, (void *)ioctl_param, sizeof(dev_info)))
+		return -EFAULT;
 
 	/* Check if name is zero-ended */
 	if (strnlen(dev_info.name, sizeof(dev_info.name)) == sizeof(dev_info.name)) {
@@ -427,15 +424,12 @@ kni_ioctl_release(struct net *net, uint32_t ioctl_num,
 	if (_IOC_SIZE(ioctl_num) > sizeof(dev_info))
 		return -EINVAL;
 
-	ret = copy_from_user(&dev_info, (void *)ioctl_param, sizeof(dev_info));
-	if (ret) {
-		pr_err("copy_from_user in kni_ioctl_release");
-		return -EIO;
-	}
+	if (copy_from_user(&dev_info, (void *)ioctl_param, sizeof(dev_info)))
+		return -EFAULT;
 
 	/* Release the network device according to its name */
 	if (strlen(dev_info.name) == 0)
-		return ret;
+		return -EINVAL;
 
 	down_write(&knet->kni_list_lock);
 	list_for_each_entry_safe(dev, n, &knet->kni_list_head, list) {