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 <p.yadav@ti.com>
Tested-by: Julien Massot <julien.massot@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Jai Luthra <j-luthra@ti.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
index cc3ebb0d96f66ca18fe637e40d4bf12755c0e36d..2a23da6a0b8ee1a47896f7e3abfab17da1adac2f 100644 (file)
--- a/drivers/media/platform/cadence/cdns-csi2rx.c
+++ b/drivers/media/platform/cadence/cdns-csi2rx.c
@@ -404,8 +404,10 @@ static int csi2rx_parse_dt(struct csi2rx_priv *csi2rx)
        asd = v4l2_async_nf_add_fwnode_remote(&csi2rx->notifier, fwh,
                                              struct v4l2_async_subdev);
        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;
 
@@ -467,6 +469,7 @@ 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);
@@ -477,6 +480,8 @@ static int 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);