[PATCH 4.4 118/312] Drivers: hv: utils: use memdup_user in hvt_op_write

[Greg Kroah-Hartman]

From: Olaf Hering <o...@aepfle.de>

commit b00359642c2427da89dc8f77daa2c9e8a84e6d76 upstream.

Use memdup_user to handle OOM.

Fixes: 14b50f80c32d ('Drivers: hv: util: introduce hv_utils_transport 
abstraction')

Signed-off-by: Olaf Hering <o...@aepfle.de>
Signed-off-by: K. Y. Srinivasan <k...@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/hv/hv_utils_transport.c |    9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

--- a/drivers/hv/hv_utils_transport.c
+++ b/drivers/hv/hv_utils_transport.c
@@ -80,11 +80,10 @@ static ssize_t hvt_op_write(struct file
 
        hvt = container_of(file->f_op, struct hvutil_transport, fops);
 
-       inmsg = kzalloc(count, GFP_KERNEL);
-       if (copy_from_user(inmsg, buf, count)) {
-               kfree(inmsg);
-               return -EFAULT;
-       }
+       inmsg = memdup_user(buf, count);
+       if (IS_ERR(inmsg))
+               return PTR_ERR(inmsg);
+
        if (hvt->on_msg(inmsg, count))
                return -EFAULT;
        kfree(inmsg);