[PATCH] drm/msm: correct attempted NULL pointer dereference in put_iova

From: Brian Masney
Date: Sun Jun 02 2019 - 21:05:27 EST


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@xxxxxxxxxxxxx>
---
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