diff --git a/remote-curl.c b/remote-curl.c
index b2898809bd9f6a..c2068eaf1ea180 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -212,6 +212,7 @@ static int set_option(const char *name, size_t namelen, const char *value)
 		options.refetch = 1;
 		return 0;
 	} else if (!strncmp(name, "filter", namelen)) {
+		free(options.filter);
 		options.filter = xstrdup(value);
 		return 0;
 	} else if (!strncmp(name, "object-format", namelen)) {
diff --git a/sub-process.c b/sub-process.c
index 29a65f8aebbd9d..86a0d3084b75d9 100644
--- a/sub-process.c
+++ b/sub-process.c
@@ -63,6 +63,8 @@ void subprocess_stop(struct hashmap *hashmap, struct subprocess_entry *entry)
 	finish_command(&entry->process);
 
 	hashmap_remove(hashmap, &entry->ent, NULL);
+	FREE_AND_NULL(entry->to_free);
+	entry->cmd = NULL;
 }
 
 static void subprocess_exit_handler(struct child_process *process)
@@ -100,6 +102,7 @@ int subprocess_start(struct hashmap *hashmap, struct subprocess_entry *entry, co
 	process->trace2_child_class = "subprocess";
 
 	entry->cmd = process->args.v[0];
+	entry->to_free = NULL;
 
 	err = start_command(process);
 	if (err) {
@@ -145,11 +148,13 @@ int subprocess_start_strvec(struct hashmap *hashmap,
 	process->trace2_child_class = "subprocess";
 
 	sq_quote_argv_pretty(&quoted, argv->v);
-	entry->cmd = strbuf_detach(&quoted, NULL);
+	entry->cmd = entry->to_free = strbuf_detach(&quoted, NULL);
 
 	err = start_command(process);
 	if (err) {
 		error("cannot fork to run subprocess '%s'", entry->cmd);
+		FREE_AND_NULL(entry->to_free);
+		entry->cmd = NULL;
 		return err;
 	}
 
@@ -158,6 +163,8 @@ int subprocess_start_strvec(struct hashmap *hashmap,
 	err = startfn(entry);
 	if (err) {
 		error("initialization for subprocess '%s' failed", entry->cmd);
+		FREE_AND_NULL(entry->to_free);
+		entry->cmd = NULL;
 		subprocess_stop(hashmap, entry);
 		return err;
 	}
diff --git a/sub-process.h b/sub-process.h
index 73cc536646df79..926d43ae2d2054 100644
--- a/sub-process.h
+++ b/sub-process.h
@@ -25,6 +25,12 @@
 struct subprocess_entry {
 	struct hashmap_entry ent;
 	const char *cmd;
+	/**
+	 * In case `cmd` is a `strdup()`ed value that needs to be released,
+	 * you can assign the pointer to `to_free` so that `subprocess_stop()`
+	 * will release it.
+	 */
+	char *to_free;
 	struct child_process process;
 };
 
diff --git a/transport-helper.c b/transport-helper.c
index 7513fd7eea05e4..5459010f44b54e 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -404,6 +404,7 @@ static int release_helper(struct transport *transport)
 	free(data->import_marks);
 	free(data->export_marks);
 	res = disconnect_helper(transport);
+	list_objects_filter_release(&data->transport_options.filter_options);
 	free(transport->data);
 	return res;
 }