From:   bchihi@baylibre.com
To:     daniel.lezcano@linaro.org, angelogioacchino.delregno@collabora.com,
        rafael@kernel.org, amitk@kernel.org, rui.zhang@intel.com,
        matthias.bgg@gmail.com, robh+dt@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, rdunlap@infradead.org,
        ye.xingchen@zte.com.cn, p.zabel@pengutronix.de
Cc:     linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, devicetree@vger.kernel.org,
        khilman@baylibre.com, james.lo@mediatek.com,
        rex-bc.chen@mediatek.com
Subject: [PATCH] thermal/drivers/mediatek/lvts_thermal: fix memcpy's number of bytes in lvts_calibration_init()
Date:   Tue,  7 Mar 2023 14:42:45 +0100
Message-Id: <20230307134245.83599-1-bchihi@baylibre.com>
In-Reply-To: <20230126161048.94089-1-bchihi@baylibre.com>
References: <20230126161048.94089-1-bchihi@baylibre.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Balsam CHIHI <bchihi@baylibre.com>

Replace memcpy 2 bytes by sizeof(int) bytes of LVTS calibration data.

Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Balsam CHIHI <bchihi@baylibre.com>
---
Rebased on top of thermal/linux-next
base-commit: 6828e402d06f7c574430b61c05db784cd847b19f

Original email :
Hello Balsam CHIHI,

The patch f5f633b18234: "thermal/drivers/mediatek: Add the Low
Voltage Thermal Sensor driver" from Feb 9, 2023, leads to the
following Smatch static checker warning:

        drivers/thermal/mediatek/lvts_thermal.c:562 lvts_calibration_init()
        warn: not copying enough bytes for '&lvts_ctrl->calibration[i]' (4 vs 2 bytes)

drivers/thermal/mediatek/lvts_thermal.c
    555 static int lvts_calibration_init(struct device *dev, struct lvts_ctrl *lvts_ctrl,
    556                                         const struct lvts_ctrl_data *lvts_ctrl_data,
    557                                         u8 *efuse_calibration)
    558 {
    559         int i;
    560
    561         for (i = 0; i < lvts_ctrl_data->num_lvts_sensor; i++)
--> 562                 memcpy(&lvts_ctrl->calibration[i],
    563                        efuse_calibration + lvts_ctrl_data->cal_offset[i], 2);
                                                                                  ^
This is copying an array of known ints to a u32 array.  It should copy
sizeof(int) instead of 2.  It only works because the data you're on
little endian and the data is small.

    564
    565         return 0;
    566 }

regards,
dan carpenter
---
---
 drivers/thermal/mediatek/lvts_thermal.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/thermal/mediatek/lvts_thermal.c b/drivers/thermal/mediatek/lvts_thermal.c
index ddfdcbcf6d86..b505c6b49031 100644
--- a/drivers/thermal/mediatek/lvts_thermal.c
+++ b/drivers/thermal/mediatek/lvts_thermal.c
@@ -575,7 +575,7 @@ static int lvts_calibration_init(struct device *dev, struct lvts_ctrl *lvts_ctrl
 
 	for (i = 0; i < lvts_ctrl_data->num_lvts_sensor; i++)
 		memcpy(&lvts_ctrl->calibration[i],
-		       efuse_calibration + lvts_ctrl_data->cal_offset[i], 2);
+		       efuse_calibration + lvts_ctrl_data->cal_offset[i], sizeof(int));
 
 	return 0;
 }

base-commit: 6828e402d06f7c574430b61c05db784cd847b19f
prerequisite-patch-id: 73be949bd16979769e5b94905b244dcee4a8f687
prerequisite-patch-id: d23d83a946e5b876ef01a717fd51b07df1fa08dd
prerequisite-patch-id: d67f2455eef1c4a9ecc460dbf3c2e3ad47d213ec
prerequisite-patch-id: 9076e9b3bd3cc411b7b80344211364db5f0cca17
prerequisite-patch-id: e220d6ae26786f524c249588433f02e5f5f906ad
prerequisite-patch-id: b407d2998e57678952128b3a4bac92a379132b09
prerequisite-patch-id: fbb9212ce8c3530da17d213f56fa334ce4fa1b2b
prerequisite-patch-id: 5db9eed2659028cf4419f2de3d093af7df6c2dad
prerequisite-patch-id: a83c00c628605d1c8fbe1d97074f9f28efb1bcfc
prerequisite-patch-id: 56a245620a4f8238cf1ba3844dc348de3db33845
prerequisite-patch-id: 7df24b0bf11129ddd3356eacf192cc3fdb2bcded
prerequisite-patch-id: 3213ca70cb5b26d54a7137ff40ca8cd2a795c414
prerequisite-patch-id: 6c2202e85215d1c7e8ab16a6b85922e994c68d9b
-- 
2.34.1