3.2-stable review patch.  If anyone has any objections, please let me know.

------------------

From: "Michael S. Tsirkin" <mst@redhat.com>

commit bd97120fc3d1a11f3124c7c9ba1d91f51829eb85 upstream.

If a single descriptor crosses a region, the
second chunk length should be decremented
by size translated so far, instead it includes
the full descriptor length.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <redacted>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <redacted>
---
 drivers/vhost/vhost.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c

@@ -1073,7 +1073,7 @@ static int translate_desc(struct vhost_d
 		}
 		_iov = iov + ret;
 		size = reg->memory_size - addr + reg->guest_phys_addr;
-		_iov->iov_len = min((u64)len, size);
+		_iov->iov_len = min((u64)len - s, size);
 		_iov->iov_base = (void __user *)(unsigned long)
 			(reg->userspace_addr + addr - reg->guest_phys_addr);
 		s += size;