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;
Received-SPF: SoftFail (protection.outlook.com: domain of transitioning
 asem.it discourages use of 151.1.184.193 as permitted sender)
From:   Flavio Suligoi <f.suligoi@asem.it>
To:     Lee Jones <lee@kernel.org>,
        Daniel Thompson <daniel.thompson@linaro.org>,
        Jingoo Han <jingoohan1@gmail.com>,
        Helge Deller <deller@gmx.de>,
        Dan Carpenter <dan.carpenter@linaro.org>
Cc:     dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, Flavio Suligoi <f.suligoi@asem.it>
Subject: [PATCH] backlight: mp3309c: fix uninitialized local variable
Date:   Tue, 28 Nov 2023 16:08:39 +0100
Message-Id: <20231128150839.2605003-1-f.suligoi@asem.it>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Content-Type: text/plain
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 28 Nov 2023 15:09:32.7846
 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: 30df66d4-570c-4c95-41a4-08dbf024070a
X-MS-Exchange-CrossTenant-Id: d0a766c6-7992-4344-a4a2-a467a7bb1ed2
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=d0a766c6-7992-4344-a4a2-a467a7bb1ed2;Ip=[151.1.184.193];Helo=[asas054.asem.intra]
X-MS-Exchange-CrossTenant-AuthSource: AM1PEPF000252DD.eurprd07.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Anonymous
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM7PR01MB6833
X-Spam-Status: No, score=-0.9 required=5.0 tests=DKIM_SIGNED,DKIM_VALID,
	DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,
	SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=unavailable
	autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on pete.vger.email
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (pete.vger.email [0.0.0.0]); Tue, 28 Nov 2023 07:10:05 -0800 (PST)

In the function "pm3309c_parse_dt_node", when the dimming analog control
mode (by I2C messages) is enabled, the local variable "prop_levels" is
tested without any initialization, as indicated by the following smatch
warning (thanks to Dan Carpenter for the report):

drivers/video/backlight/mp3309c.c:279 pm3309c_parse_dt_node() error: uninitialized symbol 'prop_levels'.

To avoid any problem in case of undefined behavior, we need to initialize
it to "NULL".
For consistency, I also initialize the other similar variable
"prop_pwms" in the same way.

Signed-off-by: Flavio Suligoi <f.suligoi@asem.it>
---
 drivers/video/backlight/mp3309c.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/video/backlight/mp3309c.c b/drivers/video/backlight/mp3309c.c
index 3fe4469ef43f..733cad1dd15c 100644
--- a/drivers/video/backlight/mp3309c.c
+++ b/drivers/video/backlight/mp3309c.c
@@ -203,7 +203,8 @@ static int pm3309c_parse_dt_node(struct mp3309c_chip *chip,
 				 struct mp3309c_platform_data *pdata)
 {
 	struct device_node *node = chip->dev->of_node;
-	struct property *prop_pwms, *prop_levels;
+	struct property *prop_pwms = NULL;
+	struct property *prop_levels = NULL;
 	int length = 0;
 	int ret, i;
 	unsigned int num_levels, tmp_value;
-- 
2.34.1