drm/fb-helper: Fix potential NULL pointer dereference

fb_helper is being dereferenced before it is null checked,
hence there is a potential null pointer dereference.

Fix this by moving the pointer dereference after fb_helper
has been null checked.

This issue was detected with the help of Coccinelle.

Fixes: c777990fb4 ("drm/fb-helper: Handle function NULL argument")
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20171205174628.GA31189@embeddedor.com
This commit is contained in:
Gustavo A. R. Silva 2017-12-05 11:46:28 -06:00 committed by Daniel Vetter
parent ec17f0341d
commit 89f3f35620
1 changed files with 3 additions and 1 deletions

View File

@ -178,7 +178,7 @@ EXPORT_SYMBOL(drm_fb_helper_add_one_connector);
*/
int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper)
{
struct drm_device *dev = fb_helper->dev;
struct drm_device *dev;
struct drm_connector *connector;
struct drm_connector_list_iter conn_iter;
int i, ret = 0;
@ -186,6 +186,8 @@ int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper)
if (!drm_fbdev_emulation || !fb_helper)
return 0;
dev = fb_helper->dev;
mutex_lock(&fb_helper->lock);
drm_connector_list_iter_begin(dev, &conn_iter);
drm_for_each_connector_iter(connector, &conn_iter) {