Re: [PATCH v4 06/14] of: property: Avoiding using uninitialized variable @imaplen in parse_interrupt_map()

[Rob Herring <robh@kernel.org>]

On Thu, Jan 09, 2025 at 09:26:57PM +0800, Zijun Hu wrote:
> From: Zijun Hu <quic_zijuhu@quicinc.com>
> 
> parse_interrupt_map() will use uninitialized variable @imaplen if fails
> to get property 'interrupt-map'.
> 
> Fix by using the variable after successfully getting the property.
> 
> Fixes: e7985f43609c ("of: property: Fix fw_devlink handling of interrupt-map")
> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
> ---
>  drivers/of/property.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/of/property.c b/drivers/of/property.c
> index dca1a3ebccae1093b2b11f51e8e692bca854d0e3..6245cbff3527d762c16e7f4b7b7b3d4f2e9ddbe6 100644
> --- a/drivers/of/property.c
> +++ b/drivers/of/property.c
> @@ -1391,9 +1391,9 @@ static struct device_node *parse_interrupt_map(struct device_node *np,
>  	addrcells = of_bus_n_addr_cells(np);
>  
>  	imap = of_get_property(np, "interrupt-map", &imaplen);
> -	imaplen /= sizeof(*imap);
>  	if (!imap)
>  		return NULL;
> +	imaplen /= sizeof(*imap);

sizeof() is a compile time constant, there's not an actual dereference 
here.

>  
>  	imap_end = imap + imaplen;
>  
> 
> -- 
> 2.34.1
>