From 3f27451c9f29d5ed00232968680c7838a44dcac7 Mon Sep 17 00:00:00 2001
From: Karol Herbst <kherbst@redhat.com>
Date: Mon, 14 Aug 2023 16:49:32 +0200
Subject: [PATCH] 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>
---
 drivers/gpu/drm/nouveau/nouveau_connector.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_connector.c b/drivers/gpu/drm/nouveau/nouveau_connector.c
index 49c5451cdfb16..d6dd79541f6a9 100644
--- 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);
 }