linux-kernel - [PATCH] drm/msm: correct attempted NULL pointer dereference in put

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Date:   Sun,  2 Jun 2019 21:01:31 -0400
From:   Brian Masney <masneyb@...tation.org>
To:     robdclark@...il.com, sean@...rly.run
Cc:     airlied@...ux.ie, daniel@...ll.ch, linux-arm-msm@...r.kernel.org,
        dri-devel@...ts.freedesktop.org, freedreno@...ts.freedesktop.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH] drm/msm: correct attempted NULL pointer dereference in put_iova

put_iova() would attempt to dereference a NULL pointer via the
address space pointer when no IOMMU is present. Correct this by adding
the appropriate check.

Signed-off-by: Brian Masney <masneyb@...tation.org>
---
 drivers/gpu/drm/msm/msm_gem.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index 35f55dd25994..d31d9f927887 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -352,8 +352,10 @@ put_iova(struct drm_gem_object *obj)
 	WARN_ON(!mutex_is_locked(&msm_obj->lock));
 
 	list_for_each_entry_safe(vma, tmp, &msm_obj->vmas, list) {
-		msm_gem_purge_vma(vma->aspace, vma);
-		msm_gem_close_vma(vma->aspace, vma);
+		if (vma->aspace) {
+			msm_gem_purge_vma(vma->aspace, vma);
+			msm_gem_close_vma(vma->aspace, vma);
+		}
 		del_vma(vma);
 	}
 }
-- 
2.20.1