FAILED: patch "[PATCH] drm/nouveau/disp: fix use-after-free in error handling of" failed to apply to 6.1-stable tree

The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 1b254b791d7b7dea6e8adc887fbbd51746d8bb27
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2023082146-oxidation-equate-185a@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:

1b254b791d7b ("drm/nouveau/disp: fix use-after-free in error handling of nouveau_connector_create") 773eb04d14a1 ("drm/nouveau/disp: expose conn event class")
ffd2664114c8 ("drm/nouveau/disp: expose head event class")
1d4dce284164 ("drm/nouveau/disp: switch vblank semaphore release to nvkm_event_ntfy") f43e47c090dc ("drm/nouveau/nvkm: add a replacement for nvkm_notify")
361863ceab1e ("drm/nouveau/disp: move head scanoutpos method")
a2b7eadfef59 ("drm/nouveau/disp: add head class")
8c7d980da9ba ("drm/nouveau/disp: move DP MST payload config method")
8bb30c882334 ("drm/nouveau/disp: add method to trigger DP link retrain") 016dacb60e6d ("drm/nouveau/kms: pass event mask to hpd handler")
d62f8e982cb8 ("drm/nouveau/kms: switch hpd_lock from mutex to spinlock") a62b74939063 ("drm/nouveau/disp: add method to control DPAUX pad power") 813443721331 ("drm/nouveau/disp: move DP link config into acquire")
a9f5d7721923 ("drm/nouveau/disp: move HDA ELD method")
f530bc60a30b ("drm/nouveau/disp: move HDMI config into acquire + infoframe methods") 9793083f1dd9 ("drm/nouveau/disp: move LVDS protocol information into acquire") ea6143a86c67 ("drm/nouveau/disp: move and extend the role of outp acquire/release methods")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 1b254b791d7b7dea6e8adc887fbbd51746d8bb27 Mon Sep 17 00:00:00 2001
From: Karol Herbst <[email protected]>
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

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.

index a2e0033e8a26..622f6eb9a8bf 100644
@@ -1408,8 +1408,7 @@ 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;
 		}
 
 		ret = nvif_conn_event_ctor(&nv_connector->conn, "kmsHotplug",

@@ -1426,8 +1425,7 @@ nouveau_connector_create(struct drm_device *dev,
 			if (ret) {
 				nvif_event_dtor(&nv_connector->hpd);
 				nvif_conn_dtor(&nv_connector->conn);
-				kfree(nv_connector);
-				return ERR_PTR(ret);
+				goto drm_conn_err;
 			}
 		}
 	}

@@ -1475,4 +1473,9 @@ 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);
 }

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.

---
 drivers/gpu/drm/nouveau/nouveau_connector.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

index 49c5451cdfb16..d6dd79541f6a9 100644
@@ -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);
 }

2.41.0

Now queued up, thanks.

greg k-h