Avoid (unlikely) memory leaking and ensure we properly reset the config type to a non-allocated type after free'ing.

Signed-off-by: DL6ER <dl6er@dl6er.de>

src/api/config.c

@@ -279,6 +279,7 @@ static const char *getJSONvalue(struct conf_item *conf_item, cJSON *elem, struct
 				free(conf_item->v.s);
 			// Set item
 			conf_item->v.s = strdup(elem->valuestring);
+			conf_item->t = CONF_STRING_ALLOCATED; // allocated now
 			log_debug(DEBUG_CONFIG, "%s = \"%s\"", conf_item->k, conf_item->v.s);
 			break;
 		}

src/config/cli.c

@@ -182,7 +182,7 @@ static bool readStringValue(struct conf_item *conf_item, const char *value, stru
 
 			// Free old password hash if it was allocated
 			if(conf_item->t == CONF_STRING_ALLOCATED)
-					free(conf_item->v.s);
+				free(conf_item->v.s);
 
 			// Store new password hash
 			conf_item->v.s = pwhash;

src/config/config.c

@@ -42,6 +42,8 @@ uint8_t last_checksum[SHA256_DIGEST_SIZE] = { 0 };
 
 // Private prototypes
 static bool port_in_use(const in_port_t port);
+static void reset_config_default(struct conf_item *conf_item);
+static void initConfig(struct config *conf);
 
 // Set debug flags from config struct to global debug_flags array
 // This is called whenever the config is reloaded and debug flags may have
@@ -158,7 +160,10 @@ void free_config_path(char **paths)
 
 	for(unsigned int i = 0; i < MAX_CONFIG_PATH_DEPTH; i++)
 		if(paths[i] != NULL)
+		{
 			free(paths[i]);
+			paths[i] = NULL;
+		}
 }
 
 bool __attribute__ ((pure)) check_paths_equal(char **paths1, char **paths2, unsigned int max_level)
@@ -369,6 +374,8 @@ void free_config(struct config *conf)
 				break;
 			case CONF_STRING_ALLOCATED:
 				free(copy_item->v.s);
+				copy_item->v.s = NULL;
+				copy_item->t = CONF_STRING; // not allocated anymore
 				break;
 			case CONF_JSON_STRING_ARRAY:
 				cJSON_Delete(copy_item->v.json);
@@ -377,7 +384,7 @@ void free_config(struct config *conf)
 	}
 }
 
-void initConfig(struct config *conf)
+static void initConfig(struct config *conf)
 {
 	if(config_initialized)
 		return;
@@ -1492,7 +1499,7 @@ void initConfig(struct config *conf)
 
 		// Initialize config value with default one for all *except* the log file path
 		if(conf_item != &conf->files.log.ftl)
-			reset_config(conf_item);
+			reset_config_default(conf_item);
 
 		// Parse and split paths
 		conf_item->p = gen_config_path(conf_item->k, '.');
@@ -1541,7 +1548,7 @@ void initConfig(struct config *conf)
 	}
 }
 
-void reset_config(struct conf_item *conf_item)
+static void reset_config_default(struct conf_item *conf_item)
 {
 	if(conf_item->t == CONF_JSON_STRING_ARRAY)
 	{

src/config/config.h

@@ -348,8 +348,6 @@ extern struct config config;
 // Defined in config.c
 void set_debug_flags(struct config *conf);
 void set_all_debug(struct config *conf, const bool status);
-void initConfig(struct config *conf);
-void reset_config(struct conf_item *conf_item);
 bool readFTLconf(struct config *conf, const bool rewrite);
 bool getLogFilePath(void);
 struct conf_item *get_conf_item(struct config *conf, const unsigned int n);

src/config/legacy_reader.c

@@ -66,6 +66,10 @@ bool getLogFilePathLegacy(struct config *conf, FILE *fp)
 	// No option set => use default log location
 	if(buffer == NULL)
 	{
+		// Free previously allocated memory (if any)
+		if(conf->files.log.ftl.t == CONF_STRING_ALLOCATED)
+			free(conf->files.log.ftl.v.s);
+
 		// Use standard path if no custom path was obtained from the config file
 		conf->files.log.ftl.v.s = strdup("/var/log/pihole/FTL.log");
 		conf->files.log.ftl.t = CONF_STRING_ALLOCATED;
@@ -92,6 +96,10 @@ bool getLogFilePathLegacy(struct config *conf, FILE *fp)
 		conf->files.log.ftl.v.s = NULL;
 		conf->files.log.ftl.t = CONF_STRING;
 		log_info("Using syslog facility");
+
+		// Free buffer
+		if(val_buffer != NULL)
+			free(val_buffer);
 	}
 
 	// Set string if memory allocation was successful and a value was read

src/config/password.c

@@ -199,6 +199,14 @@ static char * __attribute__((malloc)) balloon_password(const char *password,
 
 	// Build PHC string-like output (output string is 101 bytes long (measured))
 	char *output = calloc(128, sizeof(char));
+
+	if(output == NULL || salt_base64 == NULL || scratch_base64 == NULL)
+	{
+		log_err("Error while allocating memory for PHC string: %s", strerror(errno));
+		goto clean_and_exit;
+	}
+
+	// Generate PHC string
 	int size = snprintf(output, 128, "$BALLOON-SHA256$v=1$s=%zu,t=%zu$%s$%s",
 	                    s_cost,
 	                    t_cost,
@@ -213,11 +221,15 @@ static char * __attribute__((malloc)) balloon_password(const char *password,
 	}
 
 clean_and_exit:
-	free(scratch);
-	free(salt_base64);
-	free(scratch_base64);
+	// Clean up
+	if(scratch != NULL)
+		free(scratch);
+	if(salt_base64 != NULL)
+		free(salt_base64);
+	if(scratch_base64 != NULL)
+		free(scratch_base64);
 
-	return output;
+	return output; // may be NULL on failure (unlikely)
 }
 
 // Parse a PHC string and return the parameters and hash
@@ -653,6 +665,7 @@ bool set_and_check_password(struct conf_item *conf_item, const char *password)
 
 	// Set item
 	conf_item->v.s = pwhash;
+	conf_item->t = CONF_STRING_ALLOCATED;
 	log_debug(DEBUG_CONFIG, "Set %s to \"%s\"", conf_item->k, conf_item->v.s);
 
 	return true;

src/config/setupVars.c

@@ -553,7 +553,7 @@ void importsetupVarsConf(void)
 	get_conf_string_from_setupVars("DHCP_LEASETIME", &config.dhcp.leaseTime);
 
 	// If the DHCP lease time is set to "24", it is interpreted as "24h".
-	// This is some relic from the past that may still be present in some
+	// This is some relict from the past that may still be present in some
 	// setups
 	if(strcmp(config.dhcp.leaseTime.v.s, "24") == 0)
 	{