drm/ttm: Handle in-memory region copies

Fix the case where the ttm pointer may be NULL causing
a NULL pointer dereference.

Signed-off-by: Jakob Bornecrantz <jakob@vmware.com>
Signed-off-by: Thomas Hellström <thellstrom@vmware.com>
Cc: stable@vger.kernel.org

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index 7cc904d3a4d1..8369e35c0dce 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -348,7 +348,9 @@ int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
         if (old_iomap == NULL && ttm == NULL)
                 goto out2;
 
-        if (ttm->state == tt_unpopulated) {
+        /* TTM might be null for moves within the same region.
+         */
+        if (ttm && ttm->state == tt_unpopulated) {
                 ret = ttm->bdev->driver->ttm_tt_populate(ttm);
                 if (ret) {
                         /* if we fail here don't nuke the mm node