From 0a51897bfac9886d36e986d009df0317582b19a2 Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Mon, 9 Oct 2017 10:43:53 +0200 Subject: [PATCH] drm/exynos: Fix potential NULL pointer dereference in suspend/resume paths The patch 6e8edf8a7d8d: "drm/exynos: Fix suspend/resume support" introduced a new code in suspend/resume paths. However it unconditionally dereference drm_dev pointer, which might be NULL if suspend/resume happens before Exynos DRM driver components bind. This patch fixes this issue. Reported-by: Dan Carpenter Fixes: 6e8edf8a7d8d "drm/exynos: Fix suspend/resume support" Signed-off-by: Marek Szyprowski Signed-off-by: Inki Dae --- drivers/gpu/drm/exynos/exynos_drm_drv.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c b/drivers/gpu/drm/exynos/exynos_drm_drv.c index e651a58c18cf..aa770bb0153c 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_drv.c +++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c @@ -168,11 +168,13 @@ static struct drm_driver exynos_drm_driver = { static int exynos_drm_suspend(struct device *dev) { struct drm_device *drm_dev = dev_get_drvdata(dev); - struct exynos_drm_private *private = drm_dev->dev_private; + struct exynos_drm_private *private; if (pm_runtime_suspended(dev) || !drm_dev) return 0; + private = drm_dev->dev_private; + drm_kms_helper_poll_disable(drm_dev); exynos_drm_fbdev_suspend(drm_dev); private->suspend_state = drm_atomic_helper_suspend(drm_dev); @@ -188,11 +190,12 @@ static int exynos_drm_suspend(struct device *dev) static int exynos_drm_resume(struct device *dev) { struct drm_device *drm_dev = dev_get_drvdata(dev); - struct exynos_drm_private *private = drm_dev->dev_private; + struct exynos_drm_private *private; if (pm_runtime_suspended(dev) || !drm_dev) return 0; + private = drm_dev->dev_private; drm_atomic_helper_resume(drm_dev, private->suspend_state); exynos_drm_fbdev_resume(drm_dev); drm_kms_helper_poll_enable(drm_dev);