diff options
| author | Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> | 2015-06-26 04:28:24 +0300 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2015-08-27 20:25:25 +0300 |
| commit | 728757eda0dcdfac1f8d46548849cbf2597fe5da (patch) | |
| tree | 8d3fa0e5b1ace57690cecd7252f56b9db322210b /drivers | |
| parent | 6b4cd0635d2cd27836ab5f534990073e0ee1a2dd (diff) | |
| download | linux-728757eda0dcdfac1f8d46548849cbf2597fe5da.tar.xz | |
xen/gntdevt: Fix race condition in gntdev_release()
[ Upstream commit 30b03d05e07467b8c6ec683ea96b5bffcbcd3931 ]
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>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'drivers')
| -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 b7f028a8f542..91cc44611062 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -529,12 +529,14 @@ 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); |