Re: [PATCH] thermal: intel: powerclamp: fix mismatch in get function for max_idle

[srinivas pandruvada]

On Thu, 2023-10-05 at 07:17 -0400, David Arcari wrote:
> KASAN reported this
> 
>       [ 444.853098] BUG: KASAN: global-out-of-bounds in
> param_get_int+0x77/0x90
>       [ 444.853111] Read of size 4 at addr ffffffffc16c9220 by task
> cat/2105
>       ...
>       [ 444.853442] The buggy address belongs to the variable:
>       [ 444.853443] max_idle+0x0/0xffffffffffffcde0
> [intel_powerclamp]
> 
> There is a mismatch between the param_get_int and the definition of
> max_idle.  Replacing param_get_int with param_get_byte resolves this
> issue.
> 
> Fixes: ebf519710218 ("thermal: intel: powerclamp: Add two module
> parameters")
> 
> Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
> Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
> Cc: Amit Kucheria <amitk@xxxxxxxxxx>
> Cc: Zhang Rui <rui.zhang@xxxxxxxxx>
> Cc: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
> Cc: David Arcari <darcari@xxxxxxxxxx>
> Cc: Chen Yu <yu.c.chen@xxxxxxxxx>
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: David Arcari <darcari@xxxxxxxxxx>
Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>

> ---
>  drivers/thermal/intel/intel_powerclamp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/thermal/intel/intel_powerclamp.c
> b/drivers/thermal/intel/intel_powerclamp.c
> index 36243a3972fd..5ac5cb60bae6 100644
> --- a/drivers/thermal/intel/intel_powerclamp.c
> +++ b/drivers/thermal/intel/intel_powerclamp.c
> @@ -256,7 +256,7 @@ static int max_idle_set(const char *arg, const
> struct kernel_param *kp)
>  
>  static const struct kernel_param_ops max_idle_ops = {
>         .set = max_idle_set,
> -       .get = param_get_int,
> +       .get = param_get_byte,
>  };
>  
>  module_param_cb(max_idle, &max_idle_ops, &max_idle, 0644);