Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
MIME-Version: 1.0
References: <20220302033716.31272-1-nizhen@uniontech.com>
In-Reply-To: <20220302033716.31272-1-nizhen@uniontech.com>
From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Sun, 5 Jun 2022 15:31:39 +0200
Message-ID: <CAMuHMdWcFcX-g_XJaMcy7U1FR==2s_CDAVmBGz9rPTP96wX4GQ@mail.gmail.com>
Subject: Re: [PATCH] USB: host: isp116x: check return value after calling platform_get_resource()
To:     Zhen Ni <nizhen@uniontech.com>
Cc:     ok@artecdesign.ee, Greg KH <gregkh@linuxfoundation.org>,
        USB list <linux-usb@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Hi Zhen,

On Wed, Mar 2, 2022 at 11:38 PM Zhen Ni <nizhen@uniontech.com> wrote:
> It will cause null-ptr-deref if platform_get_resource() returns NULL,
> we need check the return value.
>
> Signed-off-by: Zhen Ni <nizhen@uniontech.com>

Thanks for your patch, which is now commit 134a3408c2d3f7e2
("USB: host: isp116x: check return value after calling
platform_get_resource()") upstream.

> --- a/drivers/usb/host/isp116x-hcd.c
> +++ b/drivers/usb/host/isp116x-hcd.c
> @@ -1541,10 +1541,12 @@ static int isp116x_remove(struct platform_device *pdev)
>
>         iounmap(isp116x->data_reg);
>         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> -       release_mem_region(res->start, 2);
> +       if (res)
> +               release_mem_region(res->start, 2);
>         iounmap(isp116x->addr_reg);
>         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> -       release_mem_region(res->start, 2);
> +       if (res)
> +               release_mem_region(res->start, 2);
>
>         usb_put_hcd(hcd);
>         return 0;

Please note that platform_get_resource() cannot return NULL here,
as this is the .remove() callback.  If we get here, .probe() has
already verified the pointers.

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