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;
IronPort-SDR: 0TmyzwR900fMIJIRqifaYypWoSo9O75WqfZGo55c4xwIRr+qAEAmBOJg0YndjU4MwnBLSqXkBG
 aRJT4nBydSaw==
IronPort-SDR: sL0I83nSKoqiQE70tv2oGDvJqet59QbHRzYME7aetfk9TAjR+pek0nLDUfTZ3NGdpE9FJ0qD0m
 wZUrGBZgZZfQ==
From:   "Kaneda, Erik" <erik.kaneda@intel.com>
To:     Lv Yunlong <lyl2019@mail.ustc.edu.cn>,
        "Moore, Robert" <robert.moore@intel.com>,
        "Wysocki, Rafael J" <rafael.j.wysocki@intel.com>,
        "lenb@kernel.org" <lenb@kernel.org>
CC:     "linux-acpi@vger.kernel.org" <linux-acpi@vger.kernel.org>,
        "devel@acpica.org" <devel@acpica.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH] ACPICA:dbnames: Fix a error free in
 acpi_db_walk_for_fields
Thread-Topic: [PATCH] ACPICA:dbnames: Fix a error free in
 acpi_db_walk_for_fields
Thread-Index: AQHXOwaEMMs9kJYcc06jsm/pDRsLMarLxwAw
Date:   Thu, 29 Apr 2021 18:00:36 +0000
Message-ID: <MWHPR11MB15992FA009C23A74FCBFD204F05F9@MWHPR11MB1599.namprd11.prod.outlook.com>
References: <20210427014134.3568-1-lyl2019@mail.ustc.edu.cn>
In-Reply-To: <20210427014134.3568-1-lyl2019@mail.ustc.edu.cn>
Accept-Language: en-US
Content-Language: en-US
dlp-version: 11.5.1.3
dlp-product: dlpe-windows
dlp-reaction: no-action
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-Network-Message-Id: d43b4932-1ea3-4dd2-2ca6-08d90b38b0ed
X-MS-Exchange-CrossTenant-originalarrivaltime: 29 Apr 2021 18:00:36.3673
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 46c98d88-e344-4ed4-8496-4ed7712e255d
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: l1rUZEU+o9jcHlpBXjdY7FmBIIfal+kurLMoE5TVsj1CkldxlsTAD28sW6fKwmZLf59LjGFx4nFUj5RqZZx+Lw==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: MWHPR11MB1965
X-OriginatorOrg: intel.com
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org


> -----Original Message-----
> From: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
> Sent: Monday, April 26, 2021 6:42 PM
> To: Moore, Robert <robert.moore@intel.com>; Kaneda, Erik
> <erik.kaneda@intel.com>; Wysocki, Rafael J <rafael.j.wysocki@intel.com>;
> lenb@kernel.org
> Cc: linux-acpi@vger.kernel.org; devel@acpica.org; linux-
> kernel@vger.kernel.org; Lv Yunlong <lyl2019@mail.ustc.edu.cn>
> Subject: [PATCH] ACPICA:dbnames: Fix a error free in
> acpi_db_walk_for_fields
>=20
> In acpi_db_walk_for_fields, buffer.pointer is freed in the first
> time via ACPI_FREE() after acpi_os_printf("%s ", (char *)buffer.pointer).
> But later, buffer.pointer is assigned to ret_value, and the freed
> pointer is dereferenced by ret_value, which is use after free.
>=20
> In addition, buffer.pointer is freed by ACPI_FREE() again after
> acpi_os_printf("}\n"), which is a double free.
>=20
> My patch removes the first ACPI_FREE() to avoid the uaf and double
> free bugs.
>=20

I'll take a look

Thanks

> Fixes: 5fd033288a866 ("ACPICA: debugger: add command to dump all fields
> of particular subtype")
> Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
> ---
>  drivers/acpi/acpica/dbnames.c | 1 -
>  1 file changed, 1 deletion(-)
>=20
> diff --git a/drivers/acpi/acpica/dbnames.c b/drivers/acpi/acpica/dbnames.=
c
> index 3615e1a6efd8..dabd76df15ec 100644
> --- a/drivers/acpi/acpica/dbnames.c
> +++ b/drivers/acpi/acpica/dbnames.c
> @@ -547,7 +547,6 @@ acpi_db_walk_for_fields(acpi_handle obj_handle,
>  	}
>=20
>  	acpi_os_printf("%s ", (char *)buffer.pointer);
> -	ACPI_FREE(buffer.pointer);
>=20
>  	buffer.length =3D ACPI_ALLOCATE_LOCAL_BUFFER;
>  	acpi_evaluate_object(obj_handle, NULL, NULL, &buffer);
> --
> 2.25.1
>=20