Commit 9681c3bd authored by Michael S. Tsirkin's avatar Michael S. Tsirkin Committed by Greg Kroah-Hartman

vhost: fix info leak due to uninitialized memory

commit 670ae9caaca467ea1bfd325cb2a5c98ba87f94ad upstream.

struct vhost_msg within struct vhost_msg_node is copied to userspace.
Unfortunately it turns out on 64 bit systems vhost_msg has padding after
type which gcc doesn't initialize, leaking 4 uninitialized bytes to

This padding also unfortunately means 32 bit users of this interface are
broken on a 64 bit kernel which will need to be fixed separately.

Fixes: CVE-2018-1118
Reported-by: default avatarKevin Easton <>
Signed-off-by: default avatarMichael S. Tsirkin <>
Signed-off-by: default avatarMichael S. Tsirkin <>
Signed-off-by: default avatarGreg Kroah-Hartman <>
parent a875bc1c
......@@ -2295,6 +2295,9 @@ 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;
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment