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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Wed, 13 Apr 2022 10:41:42 +0200
Message-ID: <CAMuHMdXcNBq5e6K6YUorLCF0hiFsp6VVKrUcy5E4mdAQAbH7Sg@mail.gmail.com>
Subject: Re: [PATCH V2] clk: renesas: Fix memory leak of 'cpg'
To:     Haowen Bai <baihaowen@meizu.com>
Cc:     Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
        linux-clk <linux-clk@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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Hi Haowen,

On Wed, Apr 13, 2022 at 10:30 AM Haowen Bai <baihaowen@meizu.com> wrote:
> Fix this issue by freeing the cpg when exiting the function in the
> error/normal path.
>
> Signed-off-by: Haowen Bai <baihaowen@meizu.com>

Thanks for your patch!

> --- a/drivers/clk/renesas/clk-r8a73a4.c
> +++ b/drivers/clk/renesas/clk-r8a73a4.c
> @@ -215,7 +215,7 @@ static void __init r8a73a4_cpg_clocks_init(struct device_node *np)
>
>         cpg->reg = of_iomap(np, 0);
>         if (WARN_ON(cpg->reg == NULL))
> -               return;
> +               goto out_free_cpg;

Note that this is a fatal error, i.e. no chance the system will survive this,
so cleaning up is moot.

>
>         for (i = 0; i < num_clks; ++i) {
>                 const char *name;
> @@ -233,6 +233,9 @@ static void __init r8a73a4_cpg_clocks_init(struct device_node *np)
>         }
>
>         of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
> +out_free_cpg:
> +       kfree(cpg);
> +       kfree(clks);

Both cpg and clks are still used after returning from this function,
through the registered clocks and clock provider.

>  }
>  CLK_OF_DECLARE(r8a73a4_cpg_clks, "renesas,r8a73a4-cpg-clocks",
>                r8a73a4_cpg_clocks_init);

NAKed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds