drm/nouveau/disp: fix use-after-free in error handling of nouveau_connector_create

commit 1b254b791d7b7dea6e8adc887fbbd51746d8bb27 upstream.

We can't simply free the connector after calling drm_connector_init on it.
We need to clean up the drm side first.

It might not fix all regressions from commit 2b5d1c29f6c4
("drm/nouveau/disp: PIOR DP uses GPIO for HPD, not PMGR AUX interrupts"),
but at least it fixes a memory corruption in error handling related to
that commit.

Link: https://lore.kernel.org/lkml/20230806213107.GFZNARG6moWpFuSJ9W@fat_crate.local/
Fixes: 95983aea8003 ("drm/nouveau/disp: add connector class")
Signed-off-by: Karol Herbst <kherbst@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230814144933.3956959-1-kherbst@redhat.com
Signed-off-by: Karol Herbst <kherbst@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/nouveau/nouveau_connector.c b/drivers/gpu/drm/nouveau/nouveau_connector.c
index 49c5451cdfb16333953c9acd96c6d6fc1f1e26b2..d6dd79541f6a91582c8f9274079b5ca759b88cf4 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_connector.c
+++ b/drivers/gpu/drm/nouveau/nouveau_connector.c
@@ -1407,8 +1407,7 @@ nouveau_connector_create(struct drm_device *dev,
                ret = nvif_conn_ctor(&disp->disp, nv_connector->base.name, nv_connector->index,
                                     &nv_connector->conn);
                if (ret) {
-                       kfree(nv_connector);
-                       return ERR_PTR(ret);
+                       goto drm_conn_err;
                }
        }
 
@@ -1470,4 +1469,9 @@ nouveau_connector_create(struct drm_device *dev,
 
        drm_connector_register(connector);
        return connector;
+
+drm_conn_err:
+       drm_connector_cleanup(connector);
+       kfree(nv_connector);
+       return ERR_PTR(ret);
 }