Bug#15298 SHOW GRANTS FOR CURRENT_USER: Incorrect output in DEFINER context

user name is calculated on function execution stage instead of parse stage

mysql-test/r/sp_notembedded.result

@@ -206,3 +206,17 @@ drop procedure bug10100pd|
 drop procedure bug10100pc|
 drop view v1|
 drop table t3|
+drop procedure if exists bug15298_1;
+drop procedure if exists bug15298_2;
+grant all privileges on test.* to 'mysqltest_1'@'localhost';
+create procedure 15298_1 () sql security definer show grants for current_user;
+create procedure 15298_2 () sql security definer show grants;
+call 15298_1();
+Grants for root@localhost
+GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' WITH GRANT OPTION
+call 15298_2();
+Grants for root@localhost
+GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' WITH GRANT OPTION
+drop user mysqltest_1@localhost;
+drop procedure 15298_1;
+drop procedure 15298_2;

mysql-test/t/sp_notembedded.test

@@ -265,3 +265,23 @@ drop view v1|
 drop table t3|
 
 delimiter ;|
+
+#
+# Bug#15298 SHOW GRANTS FOR CURRENT_USER: Incorrect output in DEFINER context
+#
+--disable_warnings
+drop procedure if exists bug15298_1;
+drop procedure if exists bug15298_2;
+--enable_warnings
+grant all privileges on test.* to 'mysqltest_1'@'localhost';
+create procedure 15298_1 () sql security definer show grants for current_user;
+create procedure 15298_2 () sql security definer show grants;
+
+connect (con1,localhost,mysqltest_1,,test);
+call 15298_1();
+call 15298_2();
+
+connection default;
+drop user mysqltest_1@localhost;
+drop procedure 15298_1;
+drop procedure 15298_2;

sql/mysql_priv.h

@@ -537,6 +537,7 @@ int append_query_string(CHARSET_INFO *csinfo,
 void get_default_definer(THD *thd, LEX_USER *definer);
 LEX_USER *create_default_definer(THD *thd);
 LEX_USER *create_definer(THD *thd, LEX_STRING *user_name, LEX_STRING *host_name);
+LEX_USER *get_current_user(THD *thd, LEX_USER *user);
 
 enum enum_mysql_completiontype {
   ROLLBACK_RELEASE=-2, ROLLBACK=1,  ROLLBACK_AND_CHAIN=7,

sql/sql_acl.cc

@@ -2766,7 +2766,7 @@ bool mysql_table_grant(THD *thd, TABLE_LIST *table_list,
 {
   ulong column_priv= 0;
   List_iterator <LEX_USER> str_list (user_list);
-  LEX_USER *Str;
+  LEX_USER *Str, *tmp_Str;
   TABLE_LIST tables[3];
   bool create_new_users=0;
   char *db_name, *table_name;
@@ -2891,10 +2891,15 @@ bool mysql_table_grant(THD *thd, TABLE_LIST *table_list,
   thd->mem_root= &memex;
   grant_version++;
 
-  while ((Str = str_list++))
+  while ((tmp_Str = str_list++))
   {
     int error;
     GRANT_TABLE *grant_table;
+    if (!(Str= get_current_user(thd, tmp_Str)))
+    {
+      result= TRUE;
+      continue;
+    }  
     if (Str->host.length > HOSTNAME_LENGTH ||
 	Str->user.length > USERNAME_LENGTH)
     {
@@ -3030,7 +3035,7 @@ bool mysql_routine_grant(THD *thd, TABLE_LIST *table_list, bool is_proc,
 			 bool revoke_grant, bool no_error)
 {
   List_iterator <LEX_USER> str_list (user_list);
-  LEX_USER *Str;
+  LEX_USER *Str, *tmp_Str;
   TABLE_LIST tables[2];
   bool create_new_users=0, result=0;
   char *db_name, *table_name;
@@ -3098,10 +3103,15 @@ bool mysql_routine_grant(THD *thd, TABLE_LIST *table_list, bool is_proc,
 
   DBUG_PRINT("info",("now time to iterate and add users"));
 
-  while ((Str= str_list++))
+  while ((tmp_Str= str_list++))
   {
     int error;
     GRANT_NAME *grant_name;
+    if (!(Str= get_current_user(thd, tmp_Str)))
+    {
+      result= TRUE;
+      continue;
+    }  
     if (Str->host.length > HOSTNAME_LENGTH ||
 	Str->user.length > USERNAME_LENGTH)
     {
@@ -3170,7 +3180,7 @@ bool mysql_grant(THD *thd, const char *db, List <LEX_USER> &list,
                  ulong rights, bool revoke_grant)
 {
   List_iterator <LEX_USER> str_list (list);
-  LEX_USER *Str;
+  LEX_USER *Str, *tmp_Str;
   char tmp_db[NAME_LEN+1];
   bool create_new_users=0;
   TABLE_LIST tables[2];
@@ -3229,8 +3239,13 @@ bool mysql_grant(THD *thd, const char *db, List <LEX_USER> &list,
   grant_version++;
 
   int result=0;
-  while ((Str = str_list++))
+  while ((tmp_Str = str_list++))
   {
+    if (!(Str= get_current_user(thd, tmp_Str)))
+    {
+      result= TRUE;
+      continue;
+    }  
     if (Str->host.length > HOSTNAME_LENGTH ||
 	Str->user.length > USERNAME_LENGTH)
     {
@@ -5187,7 +5202,7 @@ bool mysql_create_user(THD *thd, List <LEX_USER> &list)
   int result;
   String wrong_users;
   ulong sql_mode;
-  LEX_USER *user_name;
+  LEX_USER *user_name, *tmp_user_name;
   List_iterator <LEX_USER> user_list(list);
   TABLE_LIST tables[GRANT_TABLES];
   DBUG_ENTER("mysql_create_user");
@@ -5199,8 +5214,13 @@ bool mysql_create_user(THD *thd, List <LEX_USER> &list)
   rw_wrlock(&LOCK_grant);
   VOID(pthread_mutex_lock(&acl_cache->lock));
 
-  while ((user_name= user_list++))
+  while ((tmp_user_name= user_list++))
   {
+    if (!(user_name= get_current_user(thd, tmp_user_name)))
+    {
+      result= TRUE;
+      continue;
+    }  
     /*
       Search all in-memory structures and grant tables
       for a mention of the new user name.
@@ -5246,7 +5266,7 @@ bool mysql_drop_user(THD *thd, List <LEX_USER> &list)
 {
   int result;
   String wrong_users;
-  LEX_USER *user_name;
+  LEX_USER *user_name, *tmp_user_name;
   List_iterator <LEX_USER> user_list(list);
   TABLE_LIST tables[GRANT_TABLES];
   DBUG_ENTER("mysql_drop_user");
@@ -5258,8 +5278,14 @@ bool mysql_drop_user(THD *thd, List <LEX_USER> &list)
   rw_wrlock(&LOCK_grant);
   VOID(pthread_mutex_lock(&acl_cache->lock));
 
-  while ((user_name= user_list++))
+  while ((tmp_user_name= user_list++))
   {
+    user_name= get_current_user(thd, tmp_user_name);
+    if (!(user_name= get_current_user(thd, tmp_user_name)))
+    {
+      result= TRUE;
+      continue;
+    }  
     if (handle_grant_data(tables, 1, user_name, NULL) <= 0)
     {
       append_user(&wrong_users, user_name);
@@ -5296,8 +5322,8 @@ bool mysql_rename_user(THD *thd, List <LEX_USER> &list)
 {
   int result;
   String wrong_users;
-  LEX_USER *user_from;
-  LEX_USER *user_to;
+  LEX_USER *user_from, *tmp_user_from;
+  LEX_USER *user_to, *tmp_user_to;
   List_iterator <LEX_USER> user_list(list);
   TABLE_LIST tables[GRANT_TABLES];
   DBUG_ENTER("mysql_rename_user");
@@ -5309,9 +5335,19 @@ bool mysql_rename_user(THD *thd, List <LEX_USER> &list)
   rw_wrlock(&LOCK_grant);
   VOID(pthread_mutex_lock(&acl_cache->lock));
 
-  while ((user_from= user_list++))
+  while ((tmp_user_from= user_list++))
+  {
+    if (!(user_from= get_current_user(thd, tmp_user_from)))
+    {
+      result= TRUE;
+      continue;
+    }  
+    tmp_user_to= user_list++;
+    if (!(user_to= get_current_user(thd, tmp_user_to)))
     {
-    user_to= user_list++;
+      result= TRUE;
+      continue;
+    }  
     DBUG_ASSERT(user_to != 0); /* Syntax enforces pairs of users. */
 
     /*
@@ -5366,10 +5402,15 @@ bool mysql_revoke_all(THD *thd,  List <LEX_USER> &list)
   rw_wrlock(&LOCK_grant);
   VOID(pthread_mutex_lock(&acl_cache->lock));
 
-  LEX_USER *lex_user;
+  LEX_USER *lex_user, *tmp_lex_user;
   List_iterator <LEX_USER> user_list(list);
-  while ((lex_user=user_list++))
+  while ((tmp_lex_user= user_list++))
   {
+    if (!(lex_user= get_current_user(thd, tmp_lex_user)))
+    {
+      result= -1;
+      continue;
+    }  
     if (!find_acl_user(lex_user->host.str, lex_user->user.str, TRUE))
     {
       sql_print_error("REVOKE ALL PRIVILEGES, GRANT: User '%s'@'%s' does not "

sql/sql_parse.cc

@@ -3887,11 +3887,13 @@ mysql_execute_command(THD *thd)
 
     if (thd->security_ctx->user)              // If not replication
     {
-      LEX_USER *user;
+      LEX_USER *user, *tmp_user;
 
       List_iterator <LEX_USER> user_list(lex->users_list);
-      while ((user= user_list++))
+      while ((tmp_user= user_list++))
       {
+        if (!(user= get_current_user(thd, tmp_user)))
+          goto error;
         if (specialflag & SPECIAL_NO_RESOLVE &&
             hostname_requires_resolving(user->host.str))
           push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_WARN,
@@ -3973,12 +3975,16 @@ mysql_execute_command(THD *thd)
 	if (lex->sql_command == SQLCOM_GRANT)
 	{
 	  List_iterator <LEX_USER> str_list(lex->users_list);
-	  LEX_USER *user;
-	  while ((user=str_list++))
+	  LEX_USER *user, *tmp_user;
+	  while ((tmp_user=str_list++))
+          {
+            if (!(user= get_current_user(thd, tmp_user)))
+              goto error;
 	    reset_mqh(user);
           }
 	}
       }
+    }
     break;
   }
 #endif /*!NO_EMBEDDED_ACCESS_CHECKS*/
@@ -4030,13 +4036,18 @@ mysql_execute_command(THD *thd)
   }
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
   case SQLCOM_SHOW_GRANTS:
+  {
+    LEX_USER *grant_user= get_current_user(thd, lex->grant_user);
+    if (!grant_user)
+      goto error;
     if ((thd->security_ctx->priv_user &&
-	 !strcmp(thd->security_ctx->priv_user, lex->grant_user->user.str)) ||
+	 !strcmp(thd->security_ctx->priv_user, grant_user->user.str)) ||
 	!check_access(thd, SELECT_ACL, "mysql",0,1,0,0))
     {
-      res = mysql_show_grants(thd,lex->grant_user);
+      res = mysql_show_grants(thd, grant_user);
     }
     break;
+  }
 #endif
   case SQLCOM_HA_OPEN:
     DBUG_ASSERT(first_table == all_tables && first_table != 0);
@@ -7495,3 +7506,34 @@ LEX_USER *create_definer(THD *thd, LEX_STRING *user_name, LEX_STRING *host_name)
 
   return definer;
 }
+
+
+/*
+  Retuns information about user or current user.
+
+  SYNOPSIS
+    get_current_user()
+    thd         [in] thread handler
+    user        [in] user
+
+  RETURN
+    On success, return a valid pointer to initialized
+    LEX_USER, which contains user information.
+    On error, return 0.
+*/
+
+LEX_USER *get_current_user(THD *thd, LEX_USER *user)
+{
+  LEX_USER *curr_user;
+  if (!user->user.str)  // current_user
+  {
+    if (!(curr_user= (LEX_USER*) thd->alloc(sizeof(LEX_USER))))
+    {
+      my_error(ER_OUTOFMEMORY, MYF(0), sizeof(LEX_USER));
+      return 0;
+    }
+    get_default_definer(thd, curr_user);
+    return curr_user;
+  }
+  return user;
+}

sql/sql_yacc.yy

@@ -6510,24 +6510,10 @@ show_param:
 	  {
 	    LEX *lex=Lex;
 	    lex->sql_command= SQLCOM_SHOW_GRANTS;
-	    THD *thd= lex->thd;
-            Security_context *sctx= thd->security_ctx;
 	    LEX_USER *curr_user;
-            if (!(curr_user= (LEX_USER*) thd->alloc(sizeof(st_lex_user))))
+            if (!(curr_user= (LEX_USER*) lex->thd->alloc(sizeof(st_lex_user))))
               YYABORT;
-            curr_user->user.str= sctx->priv_user;
-            curr_user->user.length= strlen(sctx->priv_user);
-            if (*sctx->priv_host != 0)
-            {
-              curr_user->host.str= sctx->priv_host;
-              curr_user->host.length= strlen(sctx->priv_host);
-            }
-            else
-            {
-              curr_user->host.str= (char *) "%";
-              curr_user->host.length= 1;
-            }
-            curr_user->password=null_lex_str;
+            bzero(curr_user, sizeof(st_lex_user));
 	    lex->grant_user= curr_user;
 	  }
 	| GRANTS FOR_SYM user
@@ -7477,22 +7463,14 @@ user:
 	  }
 	| CURRENT_USER optional_braces
 	{
-          THD *thd= YYTHD;
-          Security_context *sctx= thd->security_ctx;
-          if (!($$=(LEX_USER*) thd->alloc(sizeof(st_lex_user))))
+          if (!($$=(LEX_USER*) YYTHD->alloc(sizeof(st_lex_user))))
             YYABORT;
-          $$->user.str= sctx->priv_user;
-          $$->user.length= strlen(sctx->priv_user);
-          if (*sctx->priv_host != 0)
-          {
-            $$->host.str= sctx->priv_host;
-            $$->host.length= strlen(sctx->priv_host);
-          }
-          else
-          {
-            $$->host.str= (char *) "%";
-            $$->host.length= 1;
-          }
+          /* 
+            empty LEX_USER means current_user and 
+            will be handled in the  get_current_user() function
+            later
+          */
+          bzero($$, sizeof(LEX_USER));
 	};
 
 /* Keyword that we allow for identifiers (except SP labels) */