drm/ttm: fix ttm_bo_add_ttm(user) failure path

commit 7c4c3960dff109bc5db4c35da481c212dadb5eb5 upstream.

ttm_tt_destroy kfrees passed object, so we need to nullify
a reference to it.

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 0e3754a3a303c18391538180b702a2b0e4c66399..778fa1a9636a003f2bb9c1e5f5cc823a69e97ab9 100644 (file)
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -343,8 +343,10 @@ static int ttm_bo_add_ttm(struct ttm_buffer_object *bo, bool zero_alloc)
 
                ret = ttm_tt_set_user(bo->ttm, current,
                                      bo->buffer_start, bo->num_pages);
-               if (unlikely(ret != 0))
+               if (unlikely(ret != 0)) {
                        ttm_tt_destroy(bo->ttm);
+                       bo->ttm = NULL;
+               }
                break;
        default:
                printk(KERN_ERR TTM_PFX "Illegal buffer object type\n");