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

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

[Ajay Kaher]

From: Prathu Baronia <prathubaronia2011@gmail.com>

From: Prathu Baronia <prathubaronia2011@gmail.com>

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@gmail.com>
Message-Id: <20230522085019.42914-1-prathubaronia2011@gmail.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
[Ajay: This is a security fix as per CVE-2024-0340]
Signed-off-by: Ajay Kaher <ajay.kaher@broadcom.com>
---
 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;

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

[Greg KH]

On Mon, Feb 05, 2024 at 10:49:37AM +0530, Ajay Kaher wrote:
> From: Prathu Baronia <prathubaronia2011@gmail.com>
> 
> From: Prathu Baronia <prathubaronia2011@gmail.com>
> 
> 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@gmail.com>
> Message-Id: <20230522085019.42914-1-prathubaronia2011@gmail.com>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
> [Ajay: This is a security fix as per CVE-2024-0340]

And this is why I am so grumpy about Red Hat and CVEs, they know how to
let us know about stuff like this, but no.  Hopefully, someday soon,
they will soon not be allowed to do this anymore.

{sigh}

Now queued up, thanks.

greg k-h