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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Tue, 3 Jan 2023 09:00:36 +0100
Message-ID: <CAMuHMdWFyKA7nUojivvTwWcmxaiUQifRRB=Kn1q-qzmn20Xkuw@mail.gmail.com>
Subject: Re: [PATCH] um: vector: Fix memory leak in vector_config
To:     Miaoqian Lin <linmq006@gmail.com>
Cc:     Richard Weinberger <richard@nod.at>,
        Anton Ivanov <anton.ivanov@cambridgegreys.com>,
        Johannes Berg <johannes@sipsolutions.net>,
        Jakub Kicinski <kuba@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Wolfram Sang <wsa+renesas@sang-engineering.com>,
        linux-um@lists.infradead.org, linux-kernel@vger.kernel.org
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Hi Miaoqian,

On Thu, Dec 29, 2022 at 8:53 AM Miaoqian Lin <linmq006@gmail.com> wrote:
> kstrdup() return newly allocated copy of the string.
> Call kfree() to release the memory when after use.
>
> Fixes: 49da7e64f33e ("High Performance UML Vector Network Driver")
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>

Thanks for your patch!

> --- a/arch/um/drivers/vector_kern.c
> +++ b/arch/um/drivers/vector_kern.c
> @@ -765,6 +765,7 @@ static int vector_config(char *str, char **error_out)
>
>         parsed = uml_parse_vector_ifspec(params);
>
> +       kfree(params);

Are you sure the memory pointed to by "params" is no longer used?
"parsed" seems to contain pointers pointing to (parts of) the string
pointed to by "params", so it cannot be freed.

>         if (parsed == NULL) {
>                 *error_out = "vector_config failed to parse parameters";
>                 return -EINVAL;

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