[PATCH v6.1.y-v4.19.y] vhost: use kzalloc() instead of kmalloc() followed by memset()

[Ajay Kaher]

From: Prathu Baronia <prathubaronia2011@xxxxxxxxx>

From: Prathu Baronia <prathubaronia2011@xxxxxxxxx>

commit 4d8df0f5f79f747d75a7d356d9b9ea40a4e4c8a9 upstream

Use kzalloc() to allocate new zeroed out msg node instead of
memsetting a node allocated with kmalloc().

Signed-off-by: Prathu Baronia <prathubaronia2011@xxxxxxxxx>
Message-Id: <20230522085019.42914-1-prathubaronia2011@xxxxxxxxx>
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
[Ajay: This is a security fix as per CVE-2024-0340]
Signed-off-by: Ajay Kaher <ajay.kaher@xxxxxxxxxxxx>
---
 drivers/vhost/vhost.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 07427302084955..ecb3b397bb3888 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -2563,12 +2563,11 @@ EXPORT_SYMBOL_GPL(vhost_disable_notify);
 /* Create a new message. */
 struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type)
 {
-	struct vhost_msg_node *node = kmalloc(sizeof *node, GFP_KERNEL);
+	/* Make sure all padding within the structure is initialized. */
+	struct vhost_msg_node *node = kzalloc(sizeof(*node), GFP_KERNEL);
 	if (!node)
 		return NULL;
 
-	/* Make sure all padding within the structure is initialized. */
-	memset(&node->msg, 0, sizeof node->msg);
 	node->vq = vq;
 	node->msg.type = type;
 	return node;