From: Rob Clark <robdcl...@chromium.org>

If a GEM object is allocated, and then exported as a dma-buf fd which is
mmap'd before or without the GEM buffer being directly mmap'd, the
vma_node could be unitialized.  This leads to a situation where the CPU
mapping is not correctly torn down in drm_vma_node_unmap().

Fixes: e5516553999f ("drm: call drm_gem_object_funcs.mmap with fake offset")
Signed-off-by: Rob Clark <robdcl...@chromium.org>
---
Note, it's possible the issue existed in some related form prior to the
commit tagged with Fixes.

 drivers/gpu/drm/drm_prime.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index e3f09f18110c..849eea154dfc 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -716,6 +716,11 @@ int drm_gem_prime_mmap(struct drm_gem_object *obj, struct 
vm_area_struct *vma)
        struct file *fil;
        int ret;
 
+       /* Ensure that the vma_node is initialized: */
+       ret = drm_gem_create_mmap_offset(obj);
+       if (ret)
+               return ret;
+
        /* Add the fake offset */
        vma->vm_pgoff += drm_vma_node_start(&obj->vma_node);
 
-- 
2.35.3

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