Hi Pratyush,
Thank you for the patch.
On Wed, Sep 15, 2021 at 05:32:30PM +0530, Pratyush Yadav wrote:
> 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@xxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Note that there are other issues in the driver in cleanup paths, in
particular a missing v4l2_async_notifier_cleanup() call in
csi2rx_parse_dt() when v4l2_async_notifier_add_fwnode_remote_subdev()
fails (moving the one from the other error path to an err label would be
best), and missing media_entity_cleanup() calls in both the probe error
path and the remove handler. Would you like to submit fixes for those ?
> ---
>
> (no changes since v3)
>
> Changes in v3:
> - New in v3.
>
> drivers/media/platform/cadence/cdns-csi2rx.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
> index 7b44ab2b8c9a..d60975f905d6 100644
> --- a/drivers/media/platform/cadence/cdns-csi2rx.c
> +++ b/drivers/media/platform/cadence/cdns-csi2rx.c
> @@ -469,6 +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);
> @@ -479,6 +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);
>
--
Regards,
Laurent Pinchart
