From 2512f298cb9886e06938e761c9e924c8448d9ab8 Mon Sep 17 00:00:00 2001
From: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Date: Wed, 2 Jan 2013 22:57:11 +0000
Subject: [PATCH] xen/gntdev: fix unsafe vma access

In gntdev_ioctl_get_offset_for_vaddr, we need to hold mmap_sem while
calling find_vma() to avoid potentially having the result freed out from
under us.  Similarly, the MMU notifier functions need to synchronize with
gntdev_vma_close to avoid map->vma being freed during their iteration.

Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
Reading git-format-patch failed