Bug#44658 Create procedure makes server crash when user does not have ALL privilege

MySQL crashes if a user without proper privileges attempts to create a procedure.

The crash happens because more than one error state is pushed onto the Diagnostic
area. In this particular case the user is denied to implicitly create a new user
account with the implicitly granted privileges ALTER- and EXECUTE ROUTINE.

The new account is needed if the original user account contained a host mask.
A user account with a host mask is a distinct user account in this context.
An alternative would be to first get the most permissive user account which
include the current user connection and then assign privileges to that
account. This behavior change is considered out of scope for this bug patch.

The implicit assignment of privileges when a user creates a stored routine is a
considered to be a feature for user convenience and as such it is not
a critical operation. Any failure to complete this operation is thus considered
non-fatal (an error becomes a warning).

The patch back ports a stack implementation of the internal error handler interface.
This enables the use of multiple error handlers so that it is possible to intercept
and cancel errors thrown by lower layers. This is needed as a error handler already
is used in the call stack emitting the errors which needs to be converted.


mysql-test/r/grant.result:
  * Added test case for bug44658
mysql-test/t/grant.test:
  * Added test case for bug44658
sql/sp.cc:
  * Removed non functional parameter no_error and my_error calls as all errors
    from this function will be converted to a warning anyway.
  * Change function return type from int to bool.
sql/sp.h:
  * Removed non functional parameter no_error and my_error calls as all errors
    from this function will be converted to a warning anyway.
  * Changed function return value from int to bool
sql/sql_acl.cc:
  * Removed the non functional no_error parameter from the function prototype.
    The function is called from two places and in one of the places we now 
    ignore errors through error handlers.
  * Introduced the parameter write_to_binlog
  * Introduced an error handler to cancel any error state from mysql_routine_grant.
  * Moved my_ok() signal from mysql_routine_grant to make it easier to avoid
    setting the wrong state in the Diagnostic area.
  * Changed the broken error state in sp_grant_privileges() to a warning
    so that if "CREATE PROCEDURE" fails because "Password hash isn't a hexidecimal
    number" it is still clear what happened.
sql/sql_acl.h:
  * Removed the non functional no_error parameter from the function prototype.
    The function is called from two places and in one of the places we now 
    ignore errors through error handlers.
  * Introduced the parameter write_to_binlog
  * Changed return type for sp_grant_privileges() from int to bool
sql/sql_class.cc:
  * Back ported implementation of internal error handler from 6.0 branch
sql/sql_class.h:
  * Back ported implementation of internal error handler from 6.0 branch
sql/sql_parse.cc:
  * Moved my_ok() signal from mysql_routine_grant() to make it easier to avoid
    setting the wrong state in the Diagnostic area.

7 files changed, 112 insertions, 69 deletions

diff --git a/sql/sp.cc b/sql/sp.cc
index 8c8149d0afc..069cb722c2d 100644
--- a/sql/sp.cc
+++ b/sql/sp.cc
@@ -1308,13 +1308,20 @@ sp_find_routine(THD *thd, int type, sp_name *name, sp_cache **cp,
 /**
   This is used by sql_acl.cc:mysql_routine_grant() and is used to find
   the routines in 'routines'.
+
+  @param thd Thread handler
+  @param routines List of needles in the hay stack
+  @param any Any of the needles are good enough
+
+  @return
+    @retval FALSE Found.
+    @retval TRUE  Not found
 */
 
-int
-sp_exist_routines(THD *thd, TABLE_LIST *routines, bool any, bool no_error)
+bool
+sp_exist_routines(THD *thd, TABLE_LIST *routines, bool any)
 {
   TABLE_LIST *routine;
-  bool result= 0;
   bool sp_object_found;
   DBUG_ENTER("sp_exists_routine");
   for (routine= routines; routine; routine= routine->next_global)
@@ -1336,21 +1343,16 @@ sp_exist_routines(THD *thd, TABLE_LIST *routines, bool any, bool no_error)
     if (sp_object_found)
     {
       if (any)
-        DBUG_RETURN(1);
-      result= 1;
+        break;
     }
     else if (!any)
     {
-      if (!no_error)
-      {
-	my_error(ER_SP_DOES_NOT_EXIST, MYF(0), "FUNCTION or PROCEDURE", 
-		 routine->table_name);
-	DBUG_RETURN(-1);
-      }
-      DBUG_RETURN(0);
+      my_error(ER_SP_DOES_NOT_EXIST, MYF(0), "FUNCTION or PROCEDURE",
+               routine->table_name);
+      DBUG_RETURN(TRUE);
     }
   }
-  DBUG_RETURN(result);
+  DBUG_RETURN(FALSE);
 }
 
 
diff --git a/sql/sp.h b/sql/sp.h
index 75088ea0b83..75c6856f64b 100644
--- a/sql/sp.h
+++ b/sql/sp.h
@@ -39,8 +39,8 @@ sp_head *
 sp_find_routine(THD *thd, int type, sp_name *name,
                 sp_cache **cp, bool cache_only);
 
-int
-sp_exist_routines(THD *thd, TABLE_LIST *procs, bool any, bool no_error);
+bool
+sp_exist_routines(THD *thd, TABLE_LIST *procs, bool any);
 
 int
 sp_routine_exists_in_table(THD *thd, int type, sp_name *name);
diff --git a/sql/sql_acl.cc b/sql/sql_acl.cc
index b1dbb7031ce..83cf37e32dc 100644
--- a/sql/sql_acl.cc
+++ b/sql/sql_acl.cc
@@ -3191,26 +3191,24 @@ int mysql_table_grant(THD *thd, TABLE_LIST *table_list,
 }
 
 
-/*
+/**
   Store routine level grants in the privilege tables
 
-  SYNOPSIS
-    mysql_routine_grant()
-    thd			Thread handle
-    table_list		List of routines to give grant
-    is_proc             true indicates routine list are procedures
-    user_list		List of users to give grant
-    rights		Table level grant
-    revoke_grant	Set to 1 if this is a REVOKE command
+  @param thd Thread handle
+  @param table_list List of routines to give grant
+  @param is_proc Is this a list of procedures?
+  @param user_list List of users to give grant
+  @param rights Table level grant
+  @param revoke_grant Is this is a REVOKE command?
 
-  RETURN
-    0	ok
-    1	error
+  @return
+    @retval FALSE Success.
+    @retval TRUE An error occurred.
 */
 
 bool mysql_routine_grant(THD *thd, TABLE_LIST *table_list, bool is_proc,
 			 List <LEX_USER> &user_list, ulong rights,
-			 bool revoke_grant, bool no_error)
+			 bool revoke_grant, bool write_to_binlog)
 {
   List_iterator <LEX_USER> str_list (user_list);
   LEX_USER *Str, *tmp_Str;
@@ -3221,22 +3219,20 @@ bool mysql_routine_grant(THD *thd, TABLE_LIST *table_list, bool is_proc,
 
   if (!initialized)
   {
-    if (!no_error)
-      my_error(ER_OPTION_PREVENTS_STATEMENT, MYF(0),
-               "--skip-grant-tables");
+    my_error(ER_OPTION_PREVENTS_STATEMENT, MYF(0),
+             "--skip-grant-tables");
     DBUG_RETURN(TRUE);
   }
   if (rights & ~PROC_ACLS)
   {
-    if (!no_error)
-      my_message(ER_ILLEGAL_GRANT_FOR_TABLE, ER(ER_ILLEGAL_GRANT_FOR_TABLE),
-        	 MYF(0));
+    my_message(ER_ILLEGAL_GRANT_FOR_TABLE, ER(ER_ILLEGAL_GRANT_FOR_TABLE),
+               MYF(0));
     DBUG_RETURN(TRUE);
   }
 
   if (!revoke_grant)
   {
-    if (sp_exist_routines(thd, table_list, is_proc, no_error)<0)
+    if (sp_exist_routines(thd, table_list, is_proc))
       DBUG_RETURN(TRUE);
   }
 
@@ -3317,9 +3313,8 @@ bool mysql_routine_grant(THD *thd, TABLE_LIST *table_list, bool is_proc,
     {
       if (revoke_grant)
       {
-        if (!no_error)
-          my_error(ER_NONEXISTING_PROC_GRANT, MYF(0),
-		   Str->user.str, Str->host.str, table_name);
+        my_error(ER_NONEXISTING_PROC_GRANT, MYF(0),
+	         Str->user.str, Str->host.str, table_name);
 	result= TRUE;
 	continue;
       }
@@ -3344,16 +3339,14 @@ bool mysql_routine_grant(THD *thd, TABLE_LIST *table_list, bool is_proc,
   }
   thd->mem_root= old_root;
   pthread_mutex_unlock(&acl_cache->lock);
-  if (!result && !no_error)
+
+  if (write_to_binlog)
   {
     write_bin_log(thd, TRUE, thd->query, thd->query_length);
   }
 
   rw_unlock(&LOCK_grant);
 
-  if (!result && !no_error)
-    my_ok(thd);
-
   /* Tables are automatically closed */
   DBUG_RETURN(result);
 }
@@ -6150,21 +6143,20 @@ bool sp_revoke_privileges(THD *thd, const char *sp_db, const char *sp_name,
 }
 
 
-/*
+/**
   Grant EXECUTE,ALTER privilege for a stored procedure
 
-  SYNOPSIS
-    sp_grant_privileges()
-    thd                         The current thread.
-    db				DB of the stored procedure
-    name			Name of the stored procedure
+  @param thd The current thread.
+  @param sp_db
+  @param sp_name
+  @param is_proc
 
-  RETURN
-    0           OK.
-    < 0         Error. Error message not yet sent.
+  @return
+    @retval FALSE Success
+    @retval TRUE An error occured. Error message not yet sent.
 */
 
-int sp_grant_privileges(THD *thd, const char *sp_db, const char *sp_name,
+bool sp_grant_privileges(THD *thd, const char *sp_db, const char *sp_name,
                          bool is_proc)
 {
   Security_context *sctx= thd->security_ctx;
@@ -6174,6 +6166,7 @@ int sp_grant_privileges(THD *thd, const char *sp_db, const char *sp_name,
   bool result;
   ACL_USER *au;
   char passwd_buff[SCRAMBLED_PASSWORD_CHAR_LENGTH+1];
+  Dummy_error_handler error_handler;
   DBUG_ENTER("sp_grant_privileges");
 
   if (!(combo=(LEX_USER*) thd->alloc(sizeof(st_lex_user))))
@@ -6224,8 +6217,11 @@ int sp_grant_privileges(THD *thd, const char *sp_db, const char *sp_name,
     }
     else
     {
-      my_error(ER_PASSWD_LENGTH, MYF(0), SCRAMBLED_PASSWORD_CHAR_LENGTH);
-      return -1;
+      push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_WARN,
+                          ER_PASSWD_LENGTH,
+                          ER(ER_PASSWD_LENGTH),
+                          SCRAMBLED_PASSWORD_CHAR_LENGTH);
+      return TRUE;
     }
     combo->password.str= passwd_buff;
   }
@@ -6241,8 +6237,14 @@ int sp_grant_privileges(THD *thd, const char *sp_db, const char *sp_name,
   thd->lex->ssl_type= SSL_TYPE_NOT_SPECIFIED;
   bzero((char*) &thd->lex->mqh, sizeof(thd->lex->mqh));
 
+  /*
+    Only care about whether the operation failed or succeeded
+    as all errors will be handled later.
+  */
+  thd->push_internal_handler(&error_handler);
   result= mysql_routine_grant(thd, tables, is_proc, user_list,
-  				DEFAULT_CREATE_PROC_ACLS, 0, 1);
+                              DEFAULT_CREATE_PROC_ACLS, FALSE, FALSE);
+  thd->pop_internal_handler();
   DBUG_RETURN(result);
 }
 
diff --git a/sql/sql_acl.h b/sql/sql_acl.h
index 9ae17a4bf02..a8090fba2e7 100644
--- a/sql/sql_acl.h
+++ b/sql/sql_acl.h
@@ -233,7 +233,7 @@ int mysql_table_grant(THD *thd, TABLE_LIST *table, List <LEX_USER> &user_list,
                        bool revoke);
 bool mysql_routine_grant(THD *thd, TABLE_LIST *table, bool is_proc,
 			 List <LEX_USER> &user_list, ulong rights,
-			 bool revoke, bool no_error);
+			 bool revoke, bool write_to_binlog);
 my_bool grant_init();
 void grant_free(void);
 my_bool grant_reload(THD *thd);
@@ -264,7 +264,7 @@ void fill_effective_table_privileges(THD *thd, GRANT_INFO *grant,
                                      const char *db, const char *table);
 bool sp_revoke_privileges(THD *thd, const char *sp_db, const char *sp_name,
                           bool is_proc);
-int sp_grant_privileges(THD *thd, const char *sp_db, const char *sp_name,
+bool sp_grant_privileges(THD *thd, const char *sp_db, const char *sp_name,
                          bool is_proc);
 bool check_routine_level_acl(THD *thd, const char *db, const char *name,
                              bool is_proc);
diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index cf5fdcf27a7..a853ad103ea 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -674,31 +674,40 @@ THD::THD()
 
 void THD::push_internal_handler(Internal_error_handler *handler)
 {
-  /*
-    TODO: The current implementation is limited to 1 handler at a time only.
-    THD and sp_rcontext need to be modified to use a common handler stack.
-  */
-  DBUG_ASSERT(m_internal_handler == NULL);
-  m_internal_handler= handler;
+  if (m_internal_handler)
+  {
+    handler->m_prev_internal_handler= m_internal_handler;
+    m_internal_handler= handler;
+  }
+  else
+  {
+    m_internal_handler= handler;
+  }
 }
 
 
 bool THD::handle_error(uint sql_errno, const char *message,
                        MYSQL_ERROR::enum_warning_level level)
 {
-  if (m_internal_handler)
+  if (!m_internal_handler)
+    return FALSE;
+
+  for (Internal_error_handler *error_handler= m_internal_handler;
+       error_handler;
+       error_handler= m_internal_handler->m_prev_internal_handler)
   {
-    return m_internal_handler->handle_error(sql_errno, message, level, this);
+    if (error_handler->handle_error(sql_errno, message, level, this))
+    return TRUE;
   }
 
-  return FALSE;                                 // 'FALSE', as per coding style
+  return FALSE;
 }
 
 
 void THD::pop_internal_handler()
 {
   DBUG_ASSERT(m_internal_handler != NULL);
-  m_internal_handler= NULL;
+  m_internal_handler= m_internal_handler->m_prev_internal_handler;
 }
 
 extern "C"
diff --git a/sql/sql_class.h b/sql/sql_class.h
index ce4524fb982..4e9322dee05 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -1036,7 +1036,10 @@ show_system_thread(enum_thread_type thread)
 class Internal_error_handler
 {
 protected:
-  Internal_error_handler() {}
+  Internal_error_handler() :
+    m_prev_internal_handler(NULL)
+  {}
+
   virtual ~Internal_error_handler() {}
 
 public:
@@ -1069,6 +1072,28 @@ public:
                             const char *message,
                             MYSQL_ERROR::enum_warning_level level,
                             THD *thd) = 0;
+private:
+  Internal_error_handler *m_prev_internal_handler;
+  friend class THD;
+};
+
+
+/**
+  Implements the trivial error handler which cancels all error states
+  and prevents an SQLSTATE to be set.
+*/
+
+class Dummy_error_handler : public Internal_error_handler
+{
+public:
+  bool handle_error(uint sql_errno,
+                    const char *message,
+                    MYSQL_ERROR::enum_warning_level level,
+                    THD *thd)
+  {
+    /* Ignore error */
+    return TRUE;
+  }
 };
 
 
@@ -2210,6 +2235,9 @@ public:
   thd_scheduler scheduler;
 
 public:
+  inline Internal_error_handler *get_internal_handler()
+  { return m_internal_handler; }
+
   /**
     Add an internal error handler to the thread execution context.
     @param handler the exception handler to add
diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index 6dbe4a4fd8d..403e7bca964 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -3883,7 +3883,9 @@ end_with_restore_list:
         res= mysql_routine_grant(thd, all_tables,
                                  lex->type == TYPE_ENUM_PROCEDURE, 
                                  lex->users_list, grants,
-                                 lex->sql_command == SQLCOM_REVOKE, 0);
+                                 lex->sql_command == SQLCOM_REVOKE, TRUE);
+        if (!res)
+          my_ok(thd);
       }
       else
       {