Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:6 as permitted sender) client-ip=2620:137:e000::3:6;
From:   Armin Wolf <W_Armin@gmx.de>
To:     markpearson@lenovo.com, jorge.lopez2@hp.com
Cc:     hdegoede@redhat.com, markgross@kernel.org,
        ilpo.jarvinen@linux.intel.com, platform-driver-x86@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH v3 2/2] platform/x86: hp-bioscfg: Fix reference leak
Date:   Mon, 25 Sep 2023 15:28:44 +0200
Message-Id: <20230925132844.72479-3-W_Armin@gmx.de>
In-Reply-To: <20230925132844.72479-1-W_Armin@gmx.de>
References: <20230925132844.72479-1-W_Armin@gmx.de>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
UI-OutboundReport: notjunk:1;M01:P0:GSnf9eeADtg=;xxaEpJW0WiO5EqPgGDnYGCQtVB1
 uZH1P6q+Xxm4wDcREARAx0vv26BpbuIEnbuTF7A7iQ6e46nLOhrtWgX6GJdUMlXOwryxXQRyp
 WVcV69dY3vpi1ovGv52qqZyf2uvIlHpibtVzvCvlw6KtooVEKDhHrZqJhB+jgM938r9Kr5N1A
 sk6ZQXrBmcWVVUymCA0KRb/D+ewtPltJjv9NHxh2pEJTWLq3OgTXJklydXJJ+xP/SFmV5jOuB
 DVVS2mTZHJyC/LdTAJIzRTaeOYGKDe8OXW2k8EF8wr6XfLC+4RHHTEEG9bqqGYDsh/0cUnT9R
 3QSw4Xy2mbfhqsNbiYkpiG0DTYZyM5+StoSdLn47t3aWODgI8b7h0FJxcxmCVaZW5fbm8LEnZ
 VHNytsetZoezoAFy9KaNu943mKl9r6gbYM04WqW9hXukCMalPME21O2ujKTFQMBMI+ZRwrl5N
 rVfm6GNEHgHADSuE99ThTR6by6xY3XHscHVAWiZfMl7NdRIjehueLpWHX6G4ECe2nNsOSYEVI
 D65sUHpmduvDXU2TlimHKzR7o/ganM2W7JxXEq4sPdN+RwguDCa7uoeqfevLYZ4EKGCQ5rmvj
 WW7ldrvehSgndoX6ViqXxEUQxLUaEAo+ASBJfuvvYugCHlnz07pwybwion3ZGr7WRK/Ce7I5Y
 DBJ5nfmAcyhPWCIbmjRTYAhXIUyrME5vI9EP3g/0JIP7X9E92nmOjx9dzp4WeZnfjjeci4EvR
 Twsrd/Mhtzf/gJ3dB+18Htog9F638lrKuGurBaeiEmMbza8ciBokjMQVZgxCGXCJcQ+fRvTK6
 Lv64Ckf6VdqrcoJMniZOE2BI5OyluM9fr7IbdX9CFlJqk/fQGSz7b9+DpBhgRcwcbsqdoq9or
 b8s4UFfxMNDmm3oYpOBB9hwQ3HgB5KGtVd4bPCDwIibWg/E6LpzDhd3bdQK9DyblVuP1Dzu4Z
 ZceKSw8oiPWEYRULD1K3KXTc0pM=
Precedence: bulk

If a duplicate attribute is found using kset_find_obj(), a reference
to that attribute is returned which needs to be disposed accordingly
using kobject_put(). Use kobject_put() to dispose the duplicate
attribute in such a case.
As a side note, a very similar bug was fixed in
commit 7295a996fdab ("platform/x86: dell-sysman: Fix reference leak"),
so it seems that the bug was copied from that driver.

Compile-tested only.

Fixes: a34fc329b189 ("platform/x86: hp-bioscfg: bioscfg")
Suggested-by: Ilpo J=C3=A4rvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
=2D--
Changes in v3:
- no changes
Changes in v2:
- add patch
=2D--
 drivers/platform/x86/hp/hp-bioscfg/bioscfg.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c b/drivers/platfo=
rm/x86/hp/hp-bioscfg/bioscfg.c
index 8c4f9e12f018..0c83e66f8d0b 100644
=2D-- a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
+++ b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
@@ -659,7 +659,7 @@ static int hp_init_bios_package_attribute(enum hp_wmi_=
data_type attr_type,
 					  const char *guid, int min_elements,
 					  int instance_id)
 {
-	struct kobject *attr_name_kobj;
+	struct kobject *attr_name_kobj, *duplicate;
 	union acpi_object *elements;
 	struct kset *temp_kset;

@@ -704,8 +704,11 @@ static int hp_init_bios_package_attribute(enum hp_wmi=
_data_type attr_type,
 	}

 	/* All duplicate attributes found are ignored */
-	if (kset_find_obj(temp_kset, str_value)) {
+	duplicate =3D kset_find_obj(temp_kset, str_value);
+	if (duplicate) {
 		pr_debug("Duplicate attribute name found - %s\n", str_value);
+		/* kset_find_obj() returns a reference */
+		kobject_put(duplicate);
 		goto pack_attr_exit;
 	}

@@ -768,7 +771,7 @@ static int hp_init_bios_buffer_attribute(enum hp_wmi_d=
ata_type attr_type,
 					 const char *guid, int min_elements,
 					 int instance_id)
 {
-	struct kobject *attr_name_kobj;
+	struct kobject *attr_name_kobj, *duplicate;
 	struct kset *temp_kset;
 	char str[MAX_BUFF_SIZE];

@@ -794,8 +797,11 @@ static int hp_init_bios_buffer_attribute(enum hp_wmi_=
data_type attr_type,
 		temp_kset =3D bioscfg_drv.main_dir_kset;

 	/* All duplicate attributes found are ignored */
-	if (kset_find_obj(temp_kset, str)) {
+	duplicate =3D kset_find_obj(temp_kset, str);
+	if (duplicate) {
 		pr_debug("Duplicate attribute name found - %s\n", str);
+		/*kset_find_obj() returns a reference */
+		kobject_put(duplicate);
 		goto buff_attr_exit;
 	}

=2D-
2.39.2