This is a note to let you know that I've just added the patch titled

    vhost/net: fix heads usage of ubuf_info

to the 3.8-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     vhost-net-fix-heads-usage-of-ubuf_info.patch
and it can be found in the queue-3.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From fbec7a71b74231de6efb567e5cb4e37e89d75f84 Mon Sep 17 00:00:00 2001
From: "Michael S. Tsirkin" <[email protected]>
Date: Sun, 17 Mar 2013 02:46:09 +0000
Subject: vhost/net: fix heads usage of ubuf_info


From: "Michael S. Tsirkin" <[email protected]>

[ Upstream commit 46aa92d1ba162b4b3d6b7102440e459d4e4ee255 ]

ubuf info allocator uses guest controlled head as an index,
so a malicious guest could put the same head entry in the ring twice,
and we will get two callbacks on the same value.
To fix use upend_idx which is guaranteed to be unique.

Reported-by: Rusty Russell <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>
Cc: [email protected]
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 drivers/vhost/net.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -339,7 +339,8 @@ static void handle_tx(struct vhost_net *
                                msg.msg_controllen = 0;
                                ubufs = NULL;
                        } else {
-                               struct ubuf_info *ubuf = &vq->ubuf_info[head];
+                               struct ubuf_info *ubuf;
+                               ubuf = vq->ubuf_info + vq->upend_idx;
 
                                vq->heads[vq->upend_idx].len =
                                        VHOST_DMA_IN_PROGRESS;


Patches currently in stable-queue which might be from [email protected] are

queue-3.8/vhost-net-fix-heads-usage-of-ubuf_info.patch
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