renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2025-01-25 07:06:40 +08:00
Code

drm/fb-helper: Fix drm_fb_helper_hotplug_event() NULL ptr argument

Browse Source 
drm_fb_helper_hotplug_event() should tolerate the fb_helper argument being
NULL. Commit 03a9606e7f ("drm/fb-helper: Avoid race with DRM userspace")
introduced a fb_helper dereference before the NULL check.
Fixup by moving the dereference after the NULL check.

Fixes: 03a9606e7f ("drm/fb-helper: Avoid race with DRM userspace")
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190515132925.48867-1-noralf@tronnes.org
This commit is contained in:
Noralf Trønnes 2019-05-15 15:29:25 +02:00
parent 86d804f41e
commit 0586576950
1 changed files with 2 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
drivers/gpu/drm/drm_fb_helper.c
View File

@ -3031,7 +3031,6 @@ EXPORT_SYMBOL(drm_fb_helper_initial_config);
*/
int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
{
struct drm_device *dev = fb_helper->dev;
int err = 0;
if (!drm_fbdev_emulation || !fb_helper)
@ -3044,13 +3043,13 @@ int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
return err;
}
if (!fb_helper->fb || !drm_master_internal_acquire(dev)) {
if (!fb_helper->fb || !drm_master_internal_acquire(fb_helper->dev)) {
fb_helper->delayed_hotplug = true;
mutex_unlock(&fb_helper->lock);
return err;
}
drm_master_internal_release(dev);
drm_master_internal_release(fb_helper->dev);
DRM_DEBUG_KMS("\n");