Re: [PATCH][next] hwmon: axi-fan-control: fix uninitialized dereference of pointer res

From: Guenter Roeck
Date: Tue Feb 11 2020 - 11:39:14 EST


On Tue, Feb 11, 2020 at 04:20:59PM +0000, Colin King wrote:
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>
> Currently the resource pointer ret is uninitialized and it is
> being dereferenced when printing out a debug message. Fix this
> by fetching the resource and assigning pointer res. It is
> a moot point that we sanity check for a null res since a successful
> call to devm_platform_ioremap_resource has already occurred so
> in theory it should never be non-null.
>
> Addresses-Coverity: ("Uninitialized pointer read")
> Fixes: 690dd9ce04f6 ("hwmon: Support ADI Fan Control IP")
> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>

This has already been fixed by removing the message (and the
then unused variable). The message was useless anyway since
it printed the remapped address with %p.

Guenter

> ---
> drivers/hwmon/axi-fan-control.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/hwmon/axi-fan-control.c b/drivers/hwmon/axi-fan-control.c
> index 8041ba7cc152..36e0d060510a 100644
> --- a/drivers/hwmon/axi-fan-control.c
> +++ b/drivers/hwmon/axi-fan-control.c
> @@ -415,6 +415,9 @@ static int axi_fan_control_probe(struct platform_device *pdev)
> if (!ctl->clk_rate)
> return -EINVAL;
>
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res)
> + return -EINVAL;
> dev_dbg(&pdev->dev, "Re-mapped from 0x%08llX to %p\n",
> (unsigned long long)res->start, ctl->base);
>
> --
> 2.25.0
>