Re: [PATCH] clk: fix a missing-free bug in clk_cpy_name()

From: Jiri Slaby
Date: Wed Jun 05 2019 - 02:42:04 EST


On 31. 05. 19, 3:14, Gen Zhang wrote:
> In clk_cpy_name(), '*dst_p'('parent->name'and 'parent->fw_name') and
> 'dst' are allcoted by kstrdup_const(). According to doc: "Strings
> allocated by kstrdup_const should be freed by kfree_const". So
> 'parent->name', 'parent->fw_name' and 'dst' should be freed.
>
> Signed-off-by: Gen Zhang <blackgod016574@xxxxxxxxx>
> ---
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index aa51756..85c4d3f 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -3435,6 +3435,7 @@ static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)
> if (!dst)
> return -ENOMEM;
>
> + kfree_const(dst);

So you are now returning a freed pointer in dst_p?

> return 0;
> }
>
> @@ -3491,6 +3492,8 @@ static int clk_core_populate_parent_map(struct clk_core *core)
> kfree_const(parents[i].name);
> kfree_const(parents[i].fw_name);
> } while (--i >= 0);
> + kfree_const(parent->name);
> + kfree_const(parent->fw_name);

Both of them were just freed in the loop above, no?

thanks,
--
js
suse labs