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Date:   Thu, 7 Jun 2018 18:38:48 +0300
From:   "Michael S. Tsirkin" <mst@redhat.com>
To:     syzbot <syzbot+87cfa083e727a224754b@syzkaller.appspotmail.com>
Cc:     avagin@openvz.org, davem@davemloft.net, dingtianhong@huawei.com,
        edumazet@google.com, elena.reshetova@intel.com,
        jasowang@redhat.com, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org, matthew@mjdsystems.ca,
        mingo@kernel.org, netdev@vger.kernel.org, pabeni@redhat.com,
        syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk,
        virtualization@lists.linux-foundation.org, willemb@google.com
Subject: Re: KMSAN: uninit-value in _copy_to_iter (2)
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 <000000000000cf4578056ab12452@google.com>
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#syz test: https://github.com/google/kmsan.git/master d2d741e5d1898dfde1a75ea3d29a9a3e2edf0617

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;