Patch "drm/msm: Fix NULL deref in adreno_load_gpu" has been added to the 4.15-stable tree

This is a note to let you know that I've just added the patch titled

drm/msm: Fix NULL deref in adreno_load_gpu

to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
drm-msm-fix-null-deref-in-adreno_load_gpu.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Archit Taneja <[email protected]>
Date: Fri, 22 Dec 2017 15:41:13 +0530
Subject: drm/msm: Fix NULL deref in adreno_load_gpu

From: Archit Taneja <[email protected]>

[ Upstream commit 9dcfbc182f1aac0aa5ea194733d21e67dd2ba1fd ]

The msm/kms driver should work even if there is no GPU device specified in DT. Currently, we get a NULL dereference crash in adreno_load_gpu since the driver assumes that priv->gpu_pdev is non-NULL.

Perform an additional check on priv->gpu_pdev before trying to retrieve the msm_gpu pointer from it.

v2: Incorporate Jordan's comments:
- Simplify the check to share the same error message.
- Use dev_err_once() to avoid an error message every time we open the drm device fd.

---
 drivers/gpu/drm/msm/adreno/adreno_device.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

@@ -125,11 +125,14 @@ struct msm_gpu *adreno_load_gpu(struct d
 {
 	struct msm_drm_private *priv = dev->dev_private;
 	struct platform_device *pdev = priv->gpu_pdev;
-	struct msm_gpu *gpu = platform_get_drvdata(priv->gpu_pdev);
+	struct msm_gpu *gpu = NULL;
 	int ret;
 
+	if (pdev)
+		gpu = platform_get_drvdata(pdev);
+
 	if (!gpu) {
-		dev_err(dev->dev, "no adreno device\n");
+		dev_err_once(dev->dev, "no GPU device was found\n");
 		return NULL;
 	}
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.15/drm-msm-fix-null-deref-in-adreno_load_gpu.patch