[PATCH 4.19 2/2] drm/amdgpu: Ensure the AMDGPU file descriptor is legitimate

[Lee Jones]

[ Upstream commit b40a6ab2cf9213923bf8e821ce7fa7f6a0a26990 ]

This is a partial cherry-pick of the above upstream commit.

It ensures the file descriptor passed in by userspace is a valid one.

Cc: Felix Kuehling <Felix.Kuehling at amd.com>
Cc: Alex Deucher <alexander.deucher at amd.com>
Cc: "Christian König" <christian.koenig at amd.com>
Cc: David Airlie <airlied at linux.ie>
Cc: Daniel Vetter <daniel at ffwll.ch>
Cc: amd-gfx at lists.freedesktop.org
Cc: dri-devel at lists.freedesktop.org
Signed-off-by: Lee Jones <lee.jones at linaro.org>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index f92597c292fe5..4488aad64643b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -1044,11 +1044,15 @@ int amdgpu_amdkfd_gpuvm_acquire_process_vm(struct kgd_dev *kgd,
 					   struct dma_fence **ef)
 {
 	struct amdgpu_device *adev = get_amdgpu_device(kgd);
-	struct drm_file *drm_priv = filp->private_data;
-	struct amdgpu_fpriv *drv_priv = drm_priv->driver_priv;
-	struct amdgpu_vm *avm = &drv_priv->vm;
+	struct amdgpu_fpriv *drv_priv;
+	struct amdgpu_vm *avm;
 	int ret;
 
+	ret = amdgpu_file_to_fpriv(filp, &drv_priv);
+	if (ret)
+		return ret;
+	avm = &drv_priv->vm;
+
 	/* Already a compute VM? */
 	if (avm->process_info)
 		return -EINVAL;
-- 
2.35.1.1178.g4f1659d476-goog