Re: [PATCH] clk: imx: scu: use _safe list iterator to avoid a use after free

[Abel Vesa <abel.vesa@linaro.org>]

On 23-04-19 17:23:01, Dan Carpenter wrote:
> This loop is freeing "clk" so it needs to use list_for_each_entry_safe().
> Otherwise it dereferences a freed variable to get the next item on the
> loop.
> 
> Fixes: 77d8f3068c63 ("clk: imx: scu: add two cells binding support")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>

Reviewed-by: Abel Vesa <abel.vesa@linaro.org>

> ---
>  drivers/clk/imx/clk-scu.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/clk/imx/clk-scu.c b/drivers/clk/imx/clk-scu.c
> index 1e6870f3671f..db307890e4c1 100644
> --- a/drivers/clk/imx/clk-scu.c
> +++ b/drivers/clk/imx/clk-scu.c
> @@ -707,11 +707,11 @@ struct clk_hw *imx_clk_scu_alloc_dev(const char *name,
>  
>  void imx_clk_scu_unregister(void)
>  {
> -	struct imx_scu_clk_node *clk;
> +	struct imx_scu_clk_node *clk, *n;
>  	int i;
>  
>  	for (i = 0; i < IMX_SC_R_LAST; i++) {
> -		list_for_each_entry(clk, &imx_scu_clks[i], node) {
> +		list_for_each_entry_safe(clk, n, &imx_scu_clks[i], node) {
>  			clk_hw_unregister(clk->hw);
>  			kfree(clk);
>  		}
> -- 
> 2.39.2
>