| Message ID | 1461071271-16072-2-git-send-email-jglisse@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c index 6f3369d..11af449 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); }
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. Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Cc: <stable@vger.kernel.org> --- drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 2 ++ 1 file changed, 2 insertions(+)