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Date:   Tue, 1 Mar 2022 17:28:22 +0000
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Subject: Re: [PATCH v3 10/11] slimbus: qcom-ngd: Fix kfree() of static memory
 on setting driver_override
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To:     Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Stuart Yoder <stuyoder@gmail.com>,
        Laurentiu Tudor <laurentiu.tudor@nxp.com>,
        Abel Vesa <abel.vesa@nxp.com>, Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Fabio Estevam <festevam@gmail.com>,
        "K. Y. Srinivasan" <kys@microsoft.com>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        Stephen Hemminger <sthemmin@microsoft.com>,
        Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Vineeth Vijayan <vneethv@linux.ibm.com>,
        Peter Oberparleiter <oberpar@linux.ibm.com>,
        Heiko Carstens <hca@linux.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Alexander Gordeev <agordeev@linux.ibm.com>,
        Christian Borntraeger <borntraeger@linux.ibm.com>,
        Sven Schnelle <svens@linux.ibm.com>,
        Andy Gross <agross@kernel.org>,
        Mark Brown <broonie@kernel.org>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Jason Wang <jasowang@redhat.com>, linux-kernel@vger.kernel.org,
        linux-clk@vger.kernel.org, NXP Linux Team <linux-imx@nxp.com>,
        linux-arm-kernel@lists.infradead.org, linux-hyperv@vger.kernel.org,
        linux-pci@vger.kernel.org, linux-remoteproc@vger.kernel.org,
        linux-s390@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        alsa-devel@alsa-project.org, linux-spi@vger.kernel.org,
        virtualization@lists.linux-foundation.org,
        Linus Torvalds <torvalds@linux-foundation.org>
Cc:     Rasmus Villemoes <linux@rasmusvillemoes.dk>, stable@vger.kernel.org
References: <20220227135214.145599-1-krzysztof.kozlowski@canonical.com>
 <20220227135329.145862-4-krzysztof.kozlowski@canonical.com>
From:   Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
In-Reply-To: <20220227135329.145862-4-krzysztof.kozlowski@canonical.com>
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On 27/02/2022 13:53, Krzysztof Kozlowski wrote:
> The driver_override field from platform driver should not be initialized
> from static memory (string literal) because the core later kfree() it,
> for example when driver_override is set via sysfs.
> 
> Use dedicated helper to set driver_override properly.
> 
> Fixes: 917809e2280b ("slimbus: ngd: Add qcom SLIMBus NGD driver")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

LGTM,

Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

> ---
>   drivers/slimbus/qcom-ngd-ctrl.c | 13 ++++++++++++-
>   1 file changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/slimbus/qcom-ngd-ctrl.c b/drivers/slimbus/qcom-ngd-ctrl.c
> index 7040293c2ee8..e5d9fdb81eb0 100644
> --- a/drivers/slimbus/qcom-ngd-ctrl.c
> +++ b/drivers/slimbus/qcom-ngd-ctrl.c
> @@ -1434,6 +1434,7 @@ static int of_qcom_slim_ngd_register(struct device *parent,
>   	const struct of_device_id *match;
>   	struct device_node *node;
>   	u32 id;
> +	int ret;
>   
>   	match = of_match_node(qcom_slim_ngd_dt_match, parent->of_node);
>   	data = match->data;
> @@ -1455,7 +1456,17 @@ static int of_qcom_slim_ngd_register(struct device *parent,
>   		}
>   		ngd->id = id;
>   		ngd->pdev->dev.parent = parent;
> -		ngd->pdev->driver_override = QCOM_SLIM_NGD_DRV_NAME;
> +
> +		ret = driver_set_override(&ngd->pdev->dev,
> +					  &ngd->pdev->driver_override,
> +					  QCOM_SLIM_NGD_DRV_NAME,
> +					  strlen(QCOM_SLIM_NGD_DRV_NAME));
> +		if (ret) {
> +			platform_device_put(ngd->pdev);
> +			kfree(ngd);
> +			of_node_put(node);
> +			return ret;
> +		}
>   		ngd->pdev->dev.of_node = node;
>   		ctrl->ngd = ngd;
>