Patch "drm/vc4: Fix OOPSes from trying to cache a partially constructed BO." has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

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

    drm/vc4: Fix OOPSes from trying to cache a partially constructed BO.

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-vc4-fix-oopses-from-trying-to-cache-a-partially-constructed-bo.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 <stable@vger.kernel.org> know about it.


>From ca39b449f6d03e8235969f12f5dd25b8eb4304d6 Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Wed, 1 Mar 2017 10:56:02 -0800
Subject: drm/vc4: Fix OOPSes from trying to cache a partially constructed BO.

From: Eric Anholt <eric@anholt.net>

commit ca39b449f6d03e8235969f12f5dd25b8eb4304d6 upstream.

If a CMA allocation failed, the partially constructed BO would be
unreferenced through the normal path, and we might choose to put it in
the BO cache.  If we then reused it before it expired from the cache,
the kernel would OOPS.

Signed-off-by: Eric Anholt <eric@anholt.net>
Fixes: c826a6e10644 ("drm/vc4: Add a BO cache.")
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170301185602.6873-2-eric@anholt.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/vc4/vc4_bo.c |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/drivers/gpu/drm/vc4/vc4_bo.c
+++ b/drivers/gpu/drm/vc4/vc4_bo.c
@@ -313,6 +313,14 @@ void vc4_free_object(struct drm_gem_obje
 		goto out;
 	}
 
+	/* If this object was partially constructed but CMA allocation
+	 * had failed, just free it.
+	 */
+	if (!bo->base.vaddr) {
+		vc4_bo_destroy(bo);
+		goto out;
+	}
+
 	cache_list = vc4_get_cache_list_for_size(dev, gem_bo->size);
 	if (!cache_list) {
 		vc4_bo_destroy(bo);


Patches currently in stable-queue which might be from eric@anholt.net are

queue-4.9/drm-vc4-fix-oopses-from-trying-to-cache-a-partially-constructed-bo.patch