Patch "drm/msm: fix leak in failed get_pages" has been added to the 4.9-stable tree

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

drm/msm: fix leak in failed get_pages

to the 4.9-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-leak-in-failed-get_pages.patch
and it can be found in the queue-4.9 subdirectory.

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

From: Prakash Kamliya <[email protected]>
Date: Mon, 4 Dec 2017 19:10:15 +0530
Subject: drm/msm: fix leak in failed get_pages

From: Prakash Kamliya <[email protected]>

[ Upstream commit 62e3a3e342af3c313ab38603811ecdb1fcc79edb ]

get_pages doesn't keep a reference of the pages allocated when it fails later in the code path. This can lead to a memory leak. Keep reference of the allocated pages so that it can be freed when msm_gem_free_object gets called later during cleanup.

---
 drivers/gpu/drm/msm/msm_gem.c |   14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

@@ -91,14 +91,17 @@ static struct page **get_pages(struct dr
 			return p;
 		}
 
+		msm_obj->pages = p;
+
 		msm_obj->sgt = drm_prime_pages_to_sg(p, npages);
 		if (IS_ERR(msm_obj->sgt)) {
+			void *ptr = ERR_CAST(msm_obj->sgt);
+
 			dev_err(dev->dev, "failed to allocate sgt\n");
-			return ERR_CAST(msm_obj->sgt);
+			msm_obj->sgt = NULL;
+			return ptr;
 		}
 
-		msm_obj->pages = p;
-
 		/* For non-cached buffers, ensure the new pages are clean
 		 * because display controller, GPU, etc. are not coherent:
 		 */

@@ -121,7 +124,10 @@ static void put_pages(struct drm_gem_obj
 		if (msm_obj->flags & (MSM_BO_WC|MSM_BO_UNCACHED))
 			dma_unmap_sg(obj->dev->dev, msm_obj->sgt->sgl,
 					msm_obj->sgt->nents, DMA_BIDIRECTIONAL);
-		sg_free_table(msm_obj->sgt);
+
+		if (msm_obj->sgt)
+			sg_free_table(msm_obj->sgt);
+
 		kfree(msm_obj->sgt);
 
 		if (use_pages(obj))

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

queue-4.9/drm-msm-fix-leak-in-failed-get_pages.patch