wifi: libertas: prefer kstrtoX() for simple integer conversions

Prefer 'kstrtoX()' family of functions over 'sscanf()' to convert
strings to integers and always check results of the conversions.

Found by Linux Verification Center (linuxtesting.org) with SVACE.
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230725060531.72968-6-dmantipov@yandex.ru

drivers/net/wireless/marvell/libertas/mesh.c

@@ -188,8 +188,11 @@ static ssize_t anycast_mask_store(struct device *dev,
 	uint32_t datum;
 	int ret;
 
+	ret = kstrtouint(buf, 16, &datum);
+	if (ret)
+		return ret;
+
 	memset(&mesh_access, 0, sizeof(mesh_access));
-	sscanf(buf, "%x", &datum);
 	mesh_access.data[0] = cpu_to_le32(datum);
 
 	ret = lbs_mesh_access(priv, CMD_ACT_MESH_SET_ANYCAST, &mesh_access);
@@ -241,15 +244,14 @@ static ssize_t prb_rsp_limit_store(struct device *dev,
 	int ret;
 	unsigned long retry_limit;
 
-	memset(&mesh_access, 0, sizeof(mesh_access));
-	mesh_access.data[0] = cpu_to_le32(CMD_ACT_SET);
-
 	ret = kstrtoul(buf, 10, &retry_limit);
 	if (ret)
 		return ret;
 	if (retry_limit > 15)
 		return -ENOTSUPP;
 
+	memset(&mesh_access, 0, sizeof(mesh_access));
+	mesh_access.data[0] = cpu_to_le32(CMD_ACT_SET);
 	mesh_access.data[1] = cpu_to_le32(retry_limit);
 
 	ret = lbs_mesh_access(priv, CMD_ACT_MESH_SET_GET_PRB_RSP_LIMIT,
@@ -285,9 +287,12 @@ static ssize_t lbs_mesh_store(struct device *dev,
 			      const char *buf, size_t count)
 {
 	struct lbs_private *priv = to_net_dev(dev)->ml_priv;
-	int enable;
+	int ret, enable;
+
+	ret = kstrtoint(buf, 16, &enable);
+	if (ret)
+		return ret;
 
-	sscanf(buf, "%x", &enable);
 	enable = !!enable;
 	if (enable == !!priv->mesh_dev)
 		return count;
@@ -387,11 +392,13 @@ static ssize_t bootflag_store(struct device *dev, struct device_attribute *attr,
 	uint32_t datum;
 	int ret;
 
-	memset(&cmd, 0, sizeof(cmd));
-	ret = sscanf(buf, "%d", &datum);
-	if ((ret != 1) || (datum > 1))
+	ret = kstrtouint(buf, 10, &datum);
+	if (ret)
+		return ret;
+	if (datum > 1)
 		return -EINVAL;
 
+	memset(&cmd, 0, sizeof(cmd));
 	*((__le32 *)&cmd.data[0]) = cpu_to_le32(!!datum);
 	cmd.length = cpu_to_le16(sizeof(uint32_t));
 	ret = lbs_mesh_config_send(priv, &cmd, CMD_ACT_MESH_CONFIG_SET,
@@ -438,11 +445,14 @@ static ssize_t boottime_store(struct device *dev,
 	uint32_t datum;
 	int ret;
 
-	memset(&cmd, 0, sizeof(cmd));
-	ret = sscanf(buf, "%d", &datum);
-	if ((ret != 1) || (datum > 255))
+	ret = kstrtouint(buf, 10, &datum);
+	if (ret)
+		return ret;
+	if (datum > 255)
 		return -EINVAL;
 
+	memset(&cmd, 0, sizeof(cmd));
+
 	/* A too small boot time will result in the device booting into
 	 * standalone (no-host) mode before the host can take control of it,
 	 * so the change will be hard to revert.  This may be a desired
@@ -497,11 +507,13 @@ static ssize_t channel_store(struct device *dev, struct device_attribute *attr,
 	uint32_t datum;
 	int ret;
 
-	memset(&cmd, 0, sizeof(cmd));
-	ret = sscanf(buf, "%d", &datum);
-	if (ret != 1 || datum < 1 || datum > 11)
+	ret = kstrtouint(buf, 10, &datum);
+	if (ret)
+		return ret;
+	if (datum < 1 || datum > 11)
 		return -EINVAL;
 
+	memset(&cmd, 0, sizeof(cmd));
 	*((__le16 *)&cmd.data[0]) = cpu_to_le16(datum);
 	cmd.length = cpu_to_le16(sizeof(uint16_t));
 	ret = lbs_mesh_config_send(priv, &cmd, CMD_ACT_MESH_CONFIG_SET,
@@ -626,11 +638,14 @@ static ssize_t protocol_id_store(struct device *dev,
 	uint32_t datum;
 	int ret;
 
-	memset(&cmd, 0, sizeof(cmd));
-	ret = sscanf(buf, "%d", &datum);
-	if ((ret != 1) || (datum > 255))
+	ret = kstrtouint(buf, 10, &datum);
+	if (ret)
+		return ret;
+	if (datum > 255)
 		return -EINVAL;
 
+	memset(&cmd, 0, sizeof(cmd));
+
 	/* fetch all other Information Element parameters */
 	ret = mesh_get_default_parameters(dev, &defs);