diff options
authorJérôme Glisse <>2016-04-19 09:07:51 -0400
committerAlex Deucher <>2016-04-21 20:03:47 -0400
commit054892ed6a1645e265bc35641c2a96433a051453 (patch)
parentb5dcec693f87cb8475f2291c0075b2422addd3d6 (diff)
drm/amdgpu: forbid mapping of userptr bo through radeon device file
Allowing userptr bo which are basicly a list of page from some vma (so either anonymous page or file backed page) would lead to serious corruption of kernel structures and counters (because we overwrite the page->mapping field when mapping buffer). This will already block if the buffer was populated before anyone does try to mmap it because then TTM_PAGE_FLAG_SG would be set in in the ttm_tt flags. But that flag is check before ttm_tt_populate in the ttm vm fault handler. So to be safe just add a check to verify_access() callback. Reviewed-by: Christian König <> Signed-off-by: Jérôme Glisse <> Cc: <> Signed-off-by: Alex Deucher <>
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 6f3369de232f..11af4492b4be 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -223,6 +223,8 @@ static int amdgpu_verify_access(struct ttm_buffer_object *bo, struct file *filp)
struct amdgpu_bo *rbo = container_of(bo, struct amdgpu_bo, tbo);
+ if (amdgpu_ttm_tt_get_usermm(bo->ttm))
+ return -EPERM;
return drm_vma_node_verify_access(&rbo->gem_base.vma_node, filp);