drm: fix error routines in drm_open_helper

There are missing parts to handle error in drm_open_helper().
The priv->minor, assigned by idr_find() which can return NULL,
should be checked whether it is NULL or not before referencing it.
put_pid(), drm_gem_release(), and drm_prime_destory_file_private()
should be called when error happens after their pair functions are
called. If an error occurs after executing dev->driver->open()
which allocates driver specific per-file private data, then the
private data should be released.

Signed-off-by: YoungJun Cho <yj44.cho@samsung.com>
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Chris Wilson <chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 20 insertions, 5 deletions

diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index 429e07d0b0f1..3a24385e0368 100644
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -271,6 +271,11 @@ static int drm_open_helper(struct inode *inode, struct file *filp,
         priv->uid = current_euid();
         priv->pid = get_pid(task_pid(current));
         priv->minor = idr_find(&drm_minors_idr, minor_id);
+        if (!priv->minor) {
+                ret = -ENODEV;
+                goto out_put_pid;
+        }
+
         priv->ioctl_count = 0;
         /* for compatibility root is always authenticated */
         priv->authenticated = capable(CAP_SYS_ADMIN);
@@ -292,7 +297,7 @@ static int drm_open_helper(struct inode *inode, struct file *filp,
         if (dev->driver->open) {
                 ret = dev->driver->open(dev, priv);
                 if (ret < 0)
-                        goto out_free;
+                        goto out_prime_destroy;
         }
 
 
@@ -304,7 +309,7 @@ static int drm_open_helper(struct inode *inode, struct file *filp,
                 if (!priv->minor->master) {
                         mutex_unlock(&dev->struct_mutex);
                         ret = -ENOMEM;
-                        goto out_free;
+                        goto out_close;
                 }
 
                 priv->is_master = 1;
@@ -322,7 +327,7 @@ static int drm_open_helper(struct inode *inode, struct file *filp,
                                 drm_master_put(&priv->minor->master);
                                 drm_master_put(&priv->master);
                                 mutex_unlock(&dev->struct_mutex);
-                                goto out_free;
+                                goto out_close;
                         }
                 }
                 mutex_lock(&dev->struct_mutex);
@@ -333,7 +338,7 @@ static int drm_open_helper(struct inode *inode, struct file *filp,
                                 drm_master_put(&priv->minor->master);
                                 drm_master_put(&priv->master);
                                 mutex_unlock(&dev->struct_mutex);
-                                goto out_free;
+                                goto out_close;
                         }
                 }
                 mutex_unlock(&dev->struct_mutex);
@@ -367,7 +372,17 @@ static int drm_open_helper(struct inode *inode, struct file *filp,
 #endif
 
         return 0;
-      out_free:
+
+out_close:
+        if (dev->driver->postclose)
+                dev->driver->postclose(dev, priv);
+out_prime_destroy:
+        if (drm_core_check_feature(dev, DRIVER_PRIME))
+                drm_prime_destroy_file_private(&priv->prime);
+        if (dev->driver->driver_features & DRIVER_GEM)
+                drm_gem_release(dev, priv);
+out_put_pid:
+        put_pid(priv->pid);
         kfree(priv);
         filp->private_data = NULL;
         return ret;