Обсуждение: [HACKERS] Memory leak

Hi all，

While reading the code, I find some code that make memory leak:

- src/port/quotes.c
    At line 38, at function "escape_single_quotes_ascii",
    here used "malloc" to get some memory and return the
    pointer returned by the "malloc".
    So, any caller used this function shoule free this memory.
- /src/bin/initdb/initdb.c
    At line 327, at function "escape_quotes",
    which use function "escape_single_quotes_ascii"
    from above file.
    But at this file(/src/bin/initdb/initdb.c), there are many place
    used function "escape_quotes" but have not free the pointer returned
    by the function, thus cause memory leak.

I have fixed this bug and made a patch here:



diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index 7303bbe..4e5429e 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -1010,6 +1010,7 @@ setup_config(void)
     char        path[MAXPGPATH];
     const char *default_timezone;
     char       *autoconflines[3];
+    char       *escaped;
 
     fputs(_("creating configuration files ... "), stdout);
     fflush(stdout);
@@ -1043,20 +1044,28 @@ setup_config(void)
     conflines = replace_token(conflines, "#port = 5432", repltok);
 #endif
 
+    escaped = escape_quotes(lc_messages);
     snprintf(repltok, sizeof(repltok), "lc_messages = '%s'",
-             escape_quotes(lc_messages));
+             escaped);
+    free(escaped);
     conflines = replace_token(conflines, "#lc_messages = 'C'", repltok);
 
+    escaped = escape_quotes(lc_monetary);
     snprintf(repltok, sizeof(repltok), "lc_monetary = '%s'",
-             escape_quotes(lc_monetary));
+             escaped);
+    free(escaped);
     conflines = replace_token(conflines, "#lc_monetary = 'C'", repltok);
 
+    escaped = escape_quotes(lc_numeric);
     snprintf(repltok, sizeof(repltok), "lc_numeric = '%s'",
-             escape_quotes(lc_numeric));
+             escaped);
+    free(escaped);
     conflines = replace_token(conflines, "#lc_numeric = 'C'", repltok);
 
+    escaped = escape_quotes(lc_time);
     snprintf(repltok, sizeof(repltok), "lc_time = '%s'",
-             escape_quotes(lc_time));
+             escaped);
+    free(escaped);
     conflines = replace_token(conflines, "#lc_time = 'C'", repltok);
 
     switch (locale_date_order(lc_time))
@@ -1074,9 +1083,11 @@ setup_config(void)
     }
     conflines = replace_token(conflines, "#datestyle = 'iso, mdy'", repltok);
 
+    escaped = escape_quotes(default_text_search_config);
     snprintf(repltok, sizeof(repltok),
              "default_text_search_config = 'pg_catalog.%s'",
-             escape_quotes(default_text_search_config));
+             escaped);
+    free(escaped);
     conflines = replace_token(conflines,
                               "#default_text_search_config = 'pg_catalog.simple'",
                               repltok);
@@ -1084,11 +1095,13 @@ setup_config(void)
     default_timezone = select_default_timezone(share_path);
     if (default_timezone)
     {
+        escaped = escape_quotes(default_timezone);
         snprintf(repltok, sizeof(repltok), "timezone = '%s'",
-                 escape_quotes(default_timezone));
+                 escaped);
         conflines = replace_token(conflines, "#timezone = 'GMT'", repltok);
         snprintf(repltok, sizeof(repltok), "log_timezone = '%s'",
-                 escape_quotes(default_timezone));
+                 escaped);
+        free(escaped);
         conflines = replace_token(conflines, "#log_timezone = 'GMT'", repltok);
     }
 
@@ -1289,6 +1302,7 @@ bootstrap_template1(void)
     char      **bki_lines;
     char        headerline[MAXPGPATH];
     char        buf[64];
+    char       *escaped;
 
     printf(_("running bootstrap script ... "));
     fflush(stdout);
@@ -1330,13 +1344,19 @@ bootstrap_template1(void)
     bki_lines = replace_token(bki_lines, "FLOAT8PASSBYVAL",
                               FLOAT8PASSBYVAL ? "true" : "false");
 
-    bki_lines = replace_token(bki_lines, "POSTGRES", escape_quotes(username));
+    escaped = escape_quotes(username);
+    bki_lines = replace_token(bki_lines, "POSTGRES", escaped);
+    free(escaped);
 
     bki_lines = replace_token(bki_lines, "ENCODING", encodingid);
 
-    bki_lines = replace_token(bki_lines, "LC_COLLATE", escape_quotes(lc_collate));
+    escaped = escape_quotes(lc_collate);
+    bki_lines = replace_token(bki_lines, "LC_COLLATE", escaped);
+    free(escaped);
 
-    bki_lines = replace_token(bki_lines, "LC_CTYPE", escape_quotes(lc_ctype));
+    escaped = escape_quotes(lc_ctype);
+    bki_lines = replace_token(bki_lines, "LC_CTYPE", escaped);
+    free(escaped);
 
     /*
      * Pass correct LC_xxx environment to bootstrap.
@@ -1391,13 +1411,16 @@ setup_auth(FILE *cmdfd)
         "REVOKE ALL on pg_authid FROM public;\n\n",
         NULL
     };
+    char    *escaped;
 
     for (line = pg_authid_setup; *line != NULL; line++)
         PG_CMD_PUTS(*line);
 
+    escaped = escape_quotes(superuser_password);
     if (superuser_password)
         PG_CMD_PRINTF2("ALTER USER \"%s\" WITH PASSWORD E'%s';\n\n",
-                       username, escape_quotes(superuser_password));
+                       username, escaped);
+    free(escaped);
 }
 
 /*
@@ -1582,14 +1605,18 @@ setup_sysviews(FILE *cmdfd)
 static void
 setup_description(FILE *cmdfd)
 {
+    char       *escaped;
+
     PG_CMD_PUTS("CREATE TEMP TABLE tmp_pg_description ( "
                 "    objoid oid, "
                 "    classname name, "
                 "    objsubid int4, "
                 "    description text) WITHOUT OIDS;\n\n");
 
+    escaped = escape_quotes(desc_file);
     PG_CMD_PRINTF1("COPY tmp_pg_description FROM E'%s';\n\n",
-                   escape_quotes(desc_file));
+                   escaped);
+    free(escaped);
 
     PG_CMD_PUTS("INSERT INTO pg_description "
                 " SELECT t.objoid, c.oid, t.objsubid, t.description "
@@ -1601,8 +1628,10 @@ setup_description(FILE *cmdfd)
                 " classname name, "
                 " description text) WITHOUT OIDS;\n\n");
 
+    escaped = escape_quotes(shdesc_file);
     PG_CMD_PRINTF1("COPY tmp_pg_shdescription FROM E'%s';\n\n",
-                   escape_quotes(shdesc_file));
+                   escaped);
+    free(escaped);
 
     PG_CMD_PUTS("INSERT INTO pg_shdescription "
                 " SELECT t.objoid, c.oid, t.description "
@@ -1846,9 +1875,13 @@ setup_privileges(FILE *cmdfd)
         "        srvacl IS NOT NULL;",
         NULL
     };
+    char    *escaped;
 
+    escaped = escape_quotes(username);
     priv_lines = replace_token(privileges_setup, "$POSTGRES_SUPERUSERNAME",
-                               escape_quotes(username));
+                               escaped);
+    free(escaped);
+
     for (line = priv_lines; *line != NULL; line++)
         PG_CMD_PUTS(*line);
 }
@@ -1889,6 +1922,7 @@ setup_schema(FILE *cmdfd)
 {
     char      **line;
     char      **lines;
+    char       *escaped;
 
     lines = readfile(info_schema_file);
 
@@ -1905,11 +1939,13 @@ setup_schema(FILE *cmdfd)
                    "  WHERE implementation_info_name = 'DBMS VERSION';\n\n",
                    infoversion);
 
+    escaped = escape_quotes(features_file);
     PG_CMD_PRINTF1("COPY information_schema.sql_features "
                    "  (feature_id, feature_name, sub_feature_id, "
                    "  sub_feature_name, is_supported, comments) "
                    " FROM E'%s';\n\n",
-                   escape_quotes(features_file));
+                   escaped);
+    free(escaped);
 }
 
 /*




Hope this patch can fix this problem.
--
Yang Fan