Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <20200528185920.7314-1-wu000273@umn.edu>
In-Reply-To: <20200528185920.7314-1-wu000273@umn.edu>
From:   Ard Biesheuvel <ardb@kernel.org>
Date:   Fri, 29 May 2020 18:58:42 +0200
Message-ID: <CAMj1kXEBgHYdpT2vxQM1k93NypBHRw-tjwnKhUxaSUuLVq9tKQ@mail.gmail.com>
Subject: Re: [PATCH] efi: Fix reference count leak in efivar_create_sysfs_entry.
To:     wu000273@umn.edu
Cc:     kjlu@umn.edu, linux-efi <linux-efi@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Thu, 28 May 2020 at 20:59, <wu000273@umn.edu> wrote:
>
> From: Qiushi Wu <wu000273@umn.edu>
>
> kobject_init_and_add() should be handled when it return an error,
> because kobject_init_and_add() takes reference even when it fails.
> If this function returns an error, kobject_put() must be called to
> properly clean up the memory associated with the object. Previous
> commit "b8eb718348b8" fixed a similar problem.
>
> Signed-off-by: Qiushi Wu <wu000273@umn.edu>

This one is already fixed in linux-next

> ---
>  drivers/firmware/efi/efivars.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/firmware/efi/efivars.c b/drivers/firmware/efi/efivars.c
> index 78ad1ba8c987..26528a46d99e 100644
> --- a/drivers/firmware/efi/efivars.c
> +++ b/drivers/firmware/efi/efivars.c
> @@ -522,8 +522,10 @@ efivar_create_sysfs_entry(struct efivar_entry *new_var)
>         ret = kobject_init_and_add(&new_var->kobj, &efivar_ktype,
>                                    NULL, "%s", short_name);
>         kfree(short_name);
> -       if (ret)
> +       if (ret) {
> +               kobject_put(&new_var->kobj);
>                 return ret;
> +       }
>
>         kobject_uevent(&new_var->kobj, KOBJ_ADD);
>         if (efivar_entry_add(new_var, &efivar_sysfs_list)) {
> --
> 2.17.1
>