Re: KMSAN: uninit-value in _copy_to_iter (2)

Dmitry Vyukov
2018-06-07T16:26:03Z

[-- Attachment #1: Type: text/plain, Size: 1599 bytes --]

On Thu, Jun 7, 2018 at 5:38 PM, Michael S. Tsirkin <mst@redhat.com> wrote:
> #syz test: https://github.com/google/kmsan.git/master d2d741e5d1898dfde1a75ea3d29a9a3e2edf0617

Hi Michael,

We need:

#syz test: https://github.com/google/kmsan.git master

here. Please see
https://github.com/google/syzkaller/blob/master/docs/syzbot.md#testing-patches
for more info.

Please also add the Reported-by tag when mailing the patch for review.

Thanks

> Subject: vhost: fix info leak
>
> Fixes: CVE-2018-1118
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index f0be5f35ab28..9beefa6ed1ce 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -2345,6 +2345,9 @@ struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type)
> struct vhost_msg_node *node = kmalloc(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;
>
> --
> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/20180607183627-mutt-send-email-mst%40kernel.org.
> For more options, visit https://groups.google.com/d/optout.

[-- Attachment #2: patch --]
[-- Type: application/octet-stream, Size: 518 bytes --]

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index f0be5f35ab28..9beefa6ed1ce 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -2345,6 +2345,9 @@ struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type)
struct vhost_msg_node *node = kmalloc(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;