From c1c88d6692e86492134a397a4eeb53095eb65fd4 Mon Sep 17 00:00:00 2001
From: Pratyush Yadav
Date: Mon, 9 Oct 2023 18:39:29 +0530
Subject: [PATCH] media: cadence: csi2rx: Unregister v4l2 async notifier
[ Upstream commit b2701715301a49b53d05c7d43f3fedc3b8743bfc ]
The notifier is added to the global notifier list when registered. When
the module is removed, the struct csi2rx_priv in which the notifier is
embedded, is destroyed. As a result the notifier list has a reference to
a notifier that no longer exists. This causes invalid memory accesses
when the list is iterated over. Similar for when the probe fails.
Unregister and clean up the notifier to avoid this.
Fixes: 1fc3b37f34f6 ("media: v4l: cadence: Add Cadence MIPI-CSI2 RX driver")
Signed-off-by: Pratyush Yadav
Tested-by: Julien Massot
Reviewed-by: Laurent Pinchart
Reviewed-by: Tomi Valkeinen
Reviewed-by: Maxime Ripard
Signed-off-by: Jai Luthra
Signed-off-by: Sakari Ailus
Signed-off-by: Hans Verkuil
Signed-off-by: Sasha Levin
---
drivers/media/platform/cadence/cdns-csi2rx.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
index 0d879d71d818..9231ee7e9b3a 100644
--- a/drivers/media/platform/cadence/cdns-csi2rx.c
+++ b/drivers/media/platform/cadence/cdns-csi2rx.c
@@ -479,8 +479,10 @@ static int csi2rx_parse_dt(struct csi2rx_priv *csi2rx)
asd = v4l2_async_nf_add_fwnode_remote(&csi2rx->notifier, fwh,
struct v4l2_async_connection);
of_node_put(ep);
- if (IS_ERR(asd))
+ if (IS_ERR(asd)) {
+ v4l2_async_nf_cleanup(&csi2rx->notifier);
return PTR_ERR(asd);
+ }
csi2rx->notifier.ops = &csi2rx_notifier_ops;
@@ -543,6 +545,7 @@ static int csi2rx_probe(struct platform_device *pdev)
return 0;
err_cleanup:
+ v4l2_async_nf_unregister(&csi2rx->notifier);
v4l2_async_nf_cleanup(&csi2rx->notifier);
err_free_priv:
kfree(csi2rx);
@@ -553,6 +556,8 @@ static void csi2rx_remove(struct platform_device *pdev)
{
struct csi2rx_priv *csi2rx = platform_get_drvdata(pdev);
+ v4l2_async_nf_unregister(&csi2rx->notifier);
+ v4l2_async_nf_cleanup(&csi2rx->notifier);
v4l2_async_unregister_subdev(&csi2rx->subdev);
kfree(csi2rx);
}