Re: [PATCH] soc: qcom: geni: Fix NULL pointer dereference

[Bjorn Andersson <bjorn.andersson@linaro.org>]

On Fri 17 Jul 07:32 PDT 2020, Akash Asthana wrote:

> pdev struct doesn't exits for the devices whose status are disabled
> from DT node, in such cases NULL is returned from 'of_find_device_by_node'
> Later when we try to get drvdata from pdev struct NULL pointer dereference
> is triggered.
> 
> Add a NULL check for return values to fix the issue.
> 
> We were hitting this issue when one of QUP is disabled.
> 
> Fixes: 048eb908a1f2 ("soc: qcom-geni-se: Add interconnect support to fix earlycon crash")
> Reported-by: Sai Prakash Ranjan <saipraka@codeaurora.org>
> Signed-off-by: Akash Asthana <akashast@codeaurora.org>

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Tested-by: Bjorn Andersson <bjorn.andersson@linaro.org>

And applied with Matthias suggested rename of wrapper_pdev to pdev.


PS. Please include linux-arm-msm@vger.kernel.org among your recipients
for future patches.

Regards,
Bjorn

> ---
>  drivers/soc/qcom/qcom-geni-se.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/soc/qcom/qcom-geni-se.c b/drivers/soc/qcom/qcom-geni-se.c
> index 355d503..6e5fe65 100644
> --- a/drivers/soc/qcom/qcom-geni-se.c
> +++ b/drivers/soc/qcom/qcom-geni-se.c
> @@ -820,6 +820,7 @@ void geni_remove_earlycon_icc_vote(void)
>  	struct geni_wrapper *wrapper;
>  	struct device_node *parent;
>  	struct device_node *child;
> +	struct platform_device *wrapper_pdev;
>  
>  	if (!earlycon_wrapper)
>  		return;
> @@ -829,7 +830,12 @@ void geni_remove_earlycon_icc_vote(void)
>  	for_each_child_of_node(parent, child) {
>  		if (!of_device_is_compatible(child, "qcom,geni-se-qup"))
>  			continue;
> -		wrapper = platform_get_drvdata(of_find_device_by_node(child));
> +
> +		wrapper_pdev = of_find_device_by_node(child);
> +		if (!wrapper_pdev)
> +			continue;
> +
> +		wrapper = platform_get_drvdata(wrapper_pdev);
>  		icc_put(wrapper->to_core.path);
>  		wrapper->to_core.path = NULL;
>  
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,\na Linux Foundation Collaborative Project
>