psql: Fix memory leak with repeated calls of \bind

michaelpq · michaelpq · commit b0ae6db2088b · 2024-09-19T16:25:07.000+09:00
Calling \bind repeatedly would cause the memory allocated for the list of bind parameters to be leaked after each call, as the list is reset when beginning a single call. This issue is fixed by making the cleanup of the bind parameter list more aggressive, refactoring it into a single routine called after processing a query and before running an individual \bind. HEAD required more surgery and has been fixed by 87eeada. Issue introduced by 5b66de3. Reported-by: Anthonin Bonnefoy Discussion: https://postgr.es/m/2e5b89af-a351-ff0a-000c-037ac28314ab@gmail.com Backpatch-through: 16
diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
@@ -471,7 +471,7 @@ exec_command_bind(PsqlScanState scan_state, bool active_branch)
 		int			nparams = 0;
 		int			nalloc = 0;
 
-		pset.bind_params = NULL;
+		clean_bind_state();
 
 		while ((opt = psql_scan_slash_option(scan_state, OT_NORMAL, NULL, false)))
 		{
diff --git a/src/bin/psql/common.c b/src/bin/psql/common.c
@@ -1275,14 +1275,7 @@ SendQuery(const char *query)
 	}
 
 	/* clean up after \bind */
-	if (pset.bind_flag)
-	{
-		for (i = 0; i < pset.bind_nparams; i++)
-			free(pset.bind_params[i]);
-		free(pset.bind_params);
-		pset.bind_params = NULL;
-		pset.bind_flag = false;
-	}
+	clean_bind_state();
 
 	/* reset \gset trigger */
 	if (pset.gset_prefix)
@@ -2252,6 +2245,26 @@ uri_prefix_length(const char *connstr)
 	return 0;
 }
 
+/*
+ * Reset state related to \bind
+ *
+ * Clean up any state related to bind parameters and bind_flag.  This needs
+ * to be called after processing a query or when running \bind.
+ */
+void
+clean_bind_state(void)
+{
+	if (pset.bind_flag)
+	{
+		for (int i = 0; i < pset.bind_nparams; i++)
+			free(pset.bind_params[i]);
+		free(pset.bind_params);
+	}
+
+	pset.bind_params = NULL;
+	pset.bind_flag = false;
+}
+
 /*
  * Recognized connection string either starts with a valid URI prefix or
  * contains a "=" in it.
diff --git a/src/bin/psql/common.h b/src/bin/psql/common.h
@@ -41,6 +41,7 @@ extern bool standard_strings(void);
 extern const char *session_username(void);
 
 extern void expand_tilde(char **filename);
+extern void clean_bind_state(void);
 
 extern bool recognized_connection_string(const char *connstr);
 

Original file line number	Diff line number	Diff line change
`@@ -471,7 +471,7 @@ exec_command_bind(PsqlScanState scan_state, bool active_branch)`
`471`	`471`	`int nparams = 0;`
`472`	`472`	`int nalloc = 0;`
`473`	`473`
`474`		`- pset.bind_params = NULL;`
	`474`	`+ clean_bind_state();`
`475`	`475`
`476`	`476`	`while ((opt = psql_scan_slash_option(scan_state, OT_NORMAL, NULL, false)))`
`477`	`477`	`{`