From: Muhammad Falak R Wani <falakreyaz@gmail.com>
Date: Fri, 20 May 2016 12:18:56 +0000 (+0530)
Subject: VMCI: use memdup_user().
X-Git-Tag: v4.9-rc1~149^2~61
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=655745b0d1ebeceb0453f1c6adca154a4fac0ad5;p=karo-tx-linux.git

VMCI: use memdup_user().

Use memdup_user to duplicate a memory region from user-space to
kernel-space, instead of open coding using kmalloc & copy_from_user.

Signed-off-by: Muhammad Falak R Wani <falakreyaz@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/misc/vmw_vmci/vmci_host.c b/drivers/misc/vmw_vmci/vmci_host.c
index 9ec262a52656..ec090105eb4b 100644
--- a/drivers/misc/vmw_vmci/vmci_host.c
+++ b/drivers/misc/vmw_vmci/vmci_host.c
@@ -381,18 +381,12 @@ static int vmci_host_do_send_datagram(struct vmci_host_dev *vmci_host_dev,
 		return -EINVAL;
 	}
 
-	dg = kmalloc(send_info.len, GFP_KERNEL);
-	if (!dg) {
+	dg = memdup_user((void __user *)(uintptr_t)send_info.addr,
+			 send_info.len);
+	if (IS_ERR(dg)) {
 		vmci_ioctl_err(
 			"cannot allocate memory to dispatch datagram\n");
-		return -ENOMEM;
-	}
-
-	if (copy_from_user(dg, (void __user *)(uintptr_t)send_info.addr,
-			   send_info.len)) {
-		vmci_ioctl_err("error getting datagram\n");
-		kfree(dg);
-		return -EFAULT;
+		return PTR_ERR(dg);
 	}
 
 	if (VMCI_DG_SIZE(dg) != send_info.len) {