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From:   Amit Kucheria <amit.kucheria@verdurent.com>
Date:   Thu, 23 Apr 2020 20:01:10 +0530
Message-ID: <CAHLCerOTruxM_nJHVhjqq--gczi_MQRWGQN2zKF_BXpaz02ovw@mail.gmail.com>
Subject: Re: [PATCH] thermal: ti-soc-thermal: avoid dereferencing ERR_PTR
To:     Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc:     Eduardo Valentin <edubezval@gmail.com>, Keerthy <j-keerthy@ti.com>,
        Zhang Rui <rui.zhang@intel.com>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux PM list <linux-pm@vger.kernel.org>,
        linux-omap@vger.kernel.org
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On Thu, Apr 23, 2020 at 6:27 PM Sudip Mukherjee
<sudipm.mukherjee@gmail.com> wrote:
>
> On error the function ti_bandgap_get_sensor_data() returns the error
> code in ERR_PTR() but we only checked if the return value is NULL or
> not. And, so we can dereference a error code inside ERR_PTR.

Typo, s/a error/an error/

I see other uses of ti_bandgap_set_sensor_data() in the same file that
could use similar checks.

e.g. ti_thermal_unregister_cpu_cooling, possibly
ti_thermal_report_sensor_temperature?

>
> Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>


> ---
>  drivers/thermal/ti-soc-thermal/ti-thermal-common.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
> index d3e959d01606..1e2bf1f22dd1 100644
> --- a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
> +++ b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
> @@ -196,7 +196,7 @@ int ti_thermal_remove_sensor(struct ti_bandgap *bgp, int id)
>
>         data = ti_bandgap_get_sensor_data(bgp, id);
>
> -       if (data && data->ti_thermal) {
> +       if (!IS_ERR_OR_NULL(data) && data->ti_thermal) {
>                 if (data->our_zone)
>                         thermal_zone_device_unregister(data->ti_thermal);
>         }
> --
> 2.11.0
>