diff options
| author | Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> | 2015-06-26 03:28:24 +0200 |
|---|---|---|
| committer | David Vrabel <david.vrabel@citrix.com> | 2015-06-30 16:57:32 +0100 |
| commit | 30b03d05e07467b8c6ec683ea96b5bffcbcd3931 (patch) | |
| tree | f53898fc4128087d1ba6d03365f76472a212eba0 | |
| parent | 6684fa1cdb1ebe804e9707f389255d461b2e95b0 (diff) | |
xen/gntdevt: Fix race condition in gntdev_release()
While gntdev_release() is called the MMU notifier is still registered
and can traverse priv->maps list even if no pages are mapped (which is
the case -- gntdev_release() is called after all). But
gntdev_release() will clear that list, so make sure that only one of
those things happens at the same time.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
| -rw-r--r-- | drivers/xen/gntdev.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 67b9163db718..0dbb222daaf1 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -568,12 +568,14 @@ static int gntdev_release(struct inode *inode, struct file *flip) pr_debug("priv %p\n", priv); + mutex_lock(&priv->lock); while (!list_empty(&priv->maps)) { map = list_entry(priv->maps.next, struct grant_map, next); list_del(&map->next); gntdev_put_map(NULL /* already removed */, map); } WARN_ON(!list_empty(&priv->freeable_maps)); + mutex_unlock(&priv->lock); if (use_ptemod) mmu_notifier_unregister(&priv->mn, priv->mm); |