etnaviv: fix gem object list corruption

BugLink: http://bugs.launchpad.net/bugs/1721777
commit 518417525f3652c12fb5fad6da4ade66c0072fa3 upstream.

All manipulations of the gem_object list need to be protected by
the list mutex, as GEM objects can be created and freed in parallel.
This fixes a kernel memory corruption.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
index 9a3bea738330208841b4e2a7a50aa73f8999c64d..87b95eeedd9e84ea1733b1f004c5f37c72f34bb1 100644 (file)
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
@@ -551,12 +551,15 @@ static const struct etnaviv_gem_ops etnaviv_gem_shmem_ops = {
 void etnaviv_gem_free_object(struct drm_gem_object *obj)
 {
        struct etnaviv_gem_object *etnaviv_obj = to_etnaviv_bo(obj);
+       struct etnaviv_drm_private *priv = obj->dev->dev_private;
        struct etnaviv_vram_mapping *mapping, *tmp;
 
        /* object should not be active */
        WARN_ON(is_active(etnaviv_obj));
 
+       mutex_lock(&priv->gem_lock);
        list_del(&etnaviv_obj->gem_node);
+       mutex_unlock(&priv->gem_lock);
 
        list_for_each_entry_safe(mapping, tmp, &etnaviv_obj->vram_list,
                                 obj_node) {