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Bug#24988 FLUSH PRIVILEGES causes brief unavailability

Browse source 
- A race condition caused brief unavailablility when trying to acccess
  a table. 
- The variable 'grant_option' was removed to resolve the race condition and
  to simplify the design pattern. This flag was originally intended to optimize
  grant checks.
This commit is contained in:
thek@adventure.(none) 2007-05-28 14:08:04 +02:00
parent 1bccb382bd
commit 5f06a456bf
8 changed files with 71 additions and 121 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
sql/mysql_priv.h
View file

@ -1678,7 +1678,7 @@ extern ulong log_output_options;
extern my_bool opt_log_queries_not_using_indexes;
extern bool opt_disable_networking, opt_skip_show_db;
extern my_bool opt_character_set_client_handshake;
extern bool volatile abort_loop, shutdown_in_progress, grant_option;
extern bool volatile abort_loop, shutdown_in_progress;
extern uint volatile thread_count, thread_running, global_read_lock;
extern my_bool opt_sql_bin_update, opt_safe_user_create, opt_no_mix_types;
extern my_bool opt_safe_show_db, opt_local_infile, opt_myisam_use_mmap;

38
sql/sql_acl.cc
View file

@ -3136,7 +3136,6 @@ bool mysql_table_grant(THD *thd, TABLE_LIST *table_list,
}
}
}
thd->mem_root= old_root;
pthread_mutex_unlock(&acl_cache->lock);
@ -3310,7 +3309,6 @@ bool mysql_routine_grant(THD *thd, TABLE_LIST *table_list, bool is_proc,
continue;
}
}
thd->mem_root= old_root;
pthread_mutex_unlock(&acl_cache->lock);
if (!result && !no_error)
@ -3458,7 +3456,6 @@ bool mysql_grant(THD *thd, const char *db, List <LEX_USER> &list,
void grant_free(void)
{
DBUG_ENTER("grant_free");
grant_option = FALSE;
hash_free(&column_priv_hash);
hash_free(&proc_priv_hash);
hash_free(&func_priv_hash);
@ -3493,8 +3490,6 @@ my_bool grant_init()
delete thd;
/* Remember that we don't have a THD */
my_pthread_setspecific_ptr(THR_THD, 0);
/* Set the grant option flag so we will check grants */
grant_option= TRUE;
DBUG_RETURN(return_val);
}
@ -3553,7 +3548,6 @@ static my_bool grant_load(TABLE_LIST *tables)
if (!(mem_check=new (memex_ptr) GRANT_TABLE(t_table,c_table)))
{
/* This could only happen if we are out memory */
grant_option= FALSE;
goto end_unlock;
}
@ -3576,7 +3570,6 @@ static my_bool grant_load(TABLE_LIST *tables)
else if (my_hash_insert(&column_priv_hash,(byte*) mem_check))
{
delete mem_check;
grant_option= FALSE;
goto end_unlock;
}
}
@ -3593,7 +3586,6 @@ static my_bool grant_load(TABLE_LIST *tables)
if (!(mem_check=new (&memex) GRANT_NAME(p_table)))
{
/* This could only happen if we are out memory */
grant_option= FALSE;
goto end_unlock;
}
@ -3632,7 +3624,6 @@ static my_bool grant_load(TABLE_LIST *tables)
else if (my_hash_insert(hash, (byte*) mem_check))
{
delete mem_check;
grant_option= FALSE;
goto end_unlock;
}
}
@ -4004,8 +3995,6 @@ bool check_grant_all_columns(THD *thd, ulong want_access, GRANT_INFO *grant,
want_access &= ~grant->privilege;
if (!want_access)
return 0; // Already checked
if (!grant_option)
goto err2;
rw_rdlock(&LOCK_grant);
@ -4195,18 +4184,15 @@ bool check_routine_level_acl(THD *thd, const char *db, const char *name,
bool is_proc)
{
bool no_routine_acl= 1;
if (grant_option)
{
GRANT_NAME *grant_proc;
Security_context *sctx= thd->security_ctx;
rw_rdlock(&LOCK_grant);
if ((grant_proc= routine_hash_search(sctx->priv_host,
sctx->ip, db,
sctx->priv_user,
name, is_proc, 0)))
no_routine_acl= !(grant_proc->privs & SHOW_PROC_ACLS);
rw_unlock(&LOCK_grant);
}
GRANT_NAME *grant_proc;
Security_context *sctx= thd->security_ctx;
rw_rdlock(&LOCK_grant);
if ((grant_proc= routine_hash_search(sctx->priv_host,
sctx->ip, db,
sctx->priv_user,
name, is_proc, 0)))
no_routine_acl= !(grant_proc->privs & SHOW_PROC_ACLS);
rw_unlock(&LOCK_grant);
return no_routine_acl;
}
@ -6400,12 +6386,6 @@ void fill_effective_table_privileges(THD *thd, GRANT_INFO *grant,
/* db privileges */
grant->privilege|= acl_get(sctx->host, sctx->ip, sctx->priv_user, db, 0);
if (!grant_option)
{
DBUG_PRINT("info", ("privilege 0x%lx", grant->privilege));
DBUG_VOID_RETURN;
}
/* table privileges */
rw_rdlock(&LOCK_grant);
if (grant->version != grant_version)

2
sql/sql_db.cc
View file

@ -1448,7 +1448,7 @@ bool mysql_change_db(THD *thd, const LEX_STRING *new_db_name, bool force_switch)
if (!force_switch &&
!(db_access & DB_ACLS) &&
(!grant_option || check_grant_db(thd, new_db_file_name.str)))
check_grant_db(thd, new_db_file_name.str))
{
my_error(ER_DBACCESS_DENIED_ERROR, MYF(0),
sctx->priv_user,

15
sql/sql_insert.cc
View file

@ -189,15 +189,12 @@ static int check_insert_fields(THD *thd, TABLE_LIST *table_list,
return -1;
}
#ifndef NO_EMBEDDED_ACCESS_CHECKS
if (grant_option)
{
Field_iterator_table field_it;
field_it.set_table(table);
if (check_grant_all_columns(thd, INSERT_ACL, &table->grant,
table->s->db.str, table->s->table_name.str,
&field_it))
return -1;
}
Field_iterator_table field_it;
field_it.set_table(table);
if (check_grant_all_columns(thd, INSERT_ACL, &table->grant,
table->s->db.str, table->s->table_name.str,
&field_it))
return -1;
#endif
clear_timestamp_auto_bits(table->timestamp_field_type,
TIMESTAMP_AUTO_SET_ON_INSERT);

121
sql/sql_parse.cc
View file

@ -987,8 +987,7 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
if (check_access(thd,SELECT_ACL,table_list.db,&table_list.grant.privilege,
0, 0, test(table_list.schema_table)))
break;
if (grant_option &&
check_grant(thd, SELECT_ACL, &table_list, 2, UINT_MAX, 0))
if (check_grant(thd, SELECT_ACL, &table_list, 2, UINT_MAX, 0))
break;
/* init structures for VIEW processing */
table_list.select_lex= &(thd->lex->select_lex);
@ -2049,12 +2048,10 @@ mysql_execute_command(THD *thd)
&first_table->grant.privilege, 0, 0,
test(first_table->schema_table)))
goto error; /* purecov: inspected */
if (grant_option)
{
/* Check that the first table has CREATE privilege */
if (check_grant(thd, CREATE_ACL, all_tables, 0, 1, 0))
goto error;
}
/* Check that the first table has CREATE privilege */
if (check_grant(thd, CREATE_ACL, all_tables, 0, 1, 0))
goto error;
pthread_mutex_lock(&LOCK_active_mi);
/*
fetch_master_table will send the error to the client on failure.
@ -2320,22 +2317,20 @@ end_with_restore_list:
(TABLE_LIST *)
lex->create_info.merge_list.first))
goto error; /* purecov: inspected */
if (grant_option)
{
if (check_grant(thd, priv_needed, all_tables, 0, UINT_MAX, 0))
goto error;
if (lex->name.str && !test_all_bits(priv,INSERT_ACL | CREATE_ACL))
{ // Rename of table
TABLE_LIST tmp_table;
bzero((char*) &tmp_table,sizeof(tmp_table));
tmp_table.table_name= lex->name.str;
tmp_table.db=select_lex->db;
tmp_table.grant.privilege=priv;
if (check_grant(thd, INSERT_ACL | CREATE_ACL, &tmp_table, 0,
UINT_MAX, 0))
goto error;
}
if (check_grant(thd, priv_needed, all_tables, 0, UINT_MAX, 0))
goto error;
if (lex->name.str && !test_all_bits(priv,INSERT_ACL | CREATE_ACL))
{ // Rename of table
TABLE_LIST tmp_table;
bzero((char*) &tmp_table,sizeof(tmp_table));
tmp_table.table_name= lex->name.str;
tmp_table.db=select_lex->db;
tmp_table.grant.privilege=priv;
if (check_grant(thd, INSERT_ACL | CREATE_ACL, &tmp_table, 0,
UINT_MAX, 0))
goto error;
}
/* Don't yet allow changing of symlinks with ALTER TABLE */
if (lex->create_info.data_file_name)
push_warning(thd, MYSQL_ERROR::WARN_LEVEL_WARN, 0,
@ -2377,21 +2372,18 @@ end_with_restore_list:
&table->next_local->grant.privilege, 0, 0,
test(table->next_local->schema_table)))
goto error;
if (grant_option)
{
TABLE_LIST old_list, new_list;
/*
we do not need initialize old_list and new_list because we will
come table[0] and table->next[0] there
*/
old_list= table[0];
new_list= table->next_local[0];
if (check_grant(thd, ALTER_ACL | DROP_ACL, &old_list, 0, 1, 0) ||
(!test_all_bits(table->next_local->grant.privilege,
INSERT_ACL | CREATE_ACL) &&
check_grant(thd, INSERT_ACL | CREATE_ACL, &new_list, 0, 1, 0)))
goto error;
}
TABLE_LIST old_list, new_list;
/*
we do not need initialize old_list and new_list because we will
come table[0] and table->next[0] there
*/
old_list= table[0];
new_list= table->next_local[0];
if (check_grant(thd, ALTER_ACL | DROP_ACL, &old_list, 0, 1, 0) ||
(!test_all_bits(table->next_local->grant.privilege,
INSERT_ACL | CREATE_ACL) &&
check_grant(thd, INSERT_ACL | CREATE_ACL, &new_list, 0, 1, 0)))
goto error;
}
query_cache_invalidate3(thd, first_table, 0);
if (end_active_trans(thd) || mysql_rename_tables(thd, first_table, 0))
@ -2898,7 +2890,7 @@ end_with_restore_list:
goto error;
#else
{
if (grant_option && check_access(thd, FILE_ACL, any_db,0,0,0,0))
if (check_access(thd, FILE_ACL, any_db,0,0,0,0))
goto error;
res= ha_show_status(thd, lex->create_info.db_type, HA_ENGINE_LOGS);
break;
@ -3345,8 +3337,7 @@ end_with_restore_list:
uint grants= lex->all_privileges
? (PROC_ACLS & ~GRANT_ACL) | (lex->grant & GRANT_ACL)
: lex->grant;
if (grant_option &&
check_grant_routine(thd, grants | GRANT_ACL, all_tables,
if (check_grant_routine(thd, grants | GRANT_ACL, all_tables,
lex->type == TYPE_ENUM_PROCEDURE, 0))
goto error;
/* Conditionally writes to binlog */
@ -3357,10 +3348,8 @@ end_with_restore_list:
}
else
{
if (grant_option && check_grant(thd,
(lex->grant | lex->grant_tot_col |
GRANT_ACL),
all_tables, 0, UINT_MAX, 0))
if (check_grant(thd,(lex->grant | lex->grant_tot_col | GRANT_ACL),
all_tables, 0, UINT_MAX, 0))
goto error;
/* Conditionally writes to binlog */
res= mysql_table_grant(thd, all_tables, lex->users_list,
@ -4475,8 +4464,7 @@ bool check_single_table_access(THD *thd, ulong privilege,
goto deny;
/* Show only 1 table for check_grant */
if (grant_option &&
!(all_tables->belong_to_view &&
if (!(all_tables->belong_to_view &&
(thd->lex->sql_command == SQLCOM_SHOW_FIELDS)) &&
check_grant(thd, privilege, all_tables, 0, 1, no_errors))
goto deny;
@ -4644,9 +4632,8 @@ check_access(THD *thd, ulong want_access, const char *db, ulong *save_priv,
db_access, want_access));
db_access= ((*save_priv=(db_access | sctx->master_access)) & want_access);
/* grant_option is set if there exists a single table or column grant */
if (db_access == want_access ||
(grant_option && !dont_check_global_grants &&
(!dont_check_global_grants &&
!(want_access & ~(db_access | TABLE_ACLS | PROC_ACLS))))
DBUG_RETURN(FALSE); /* Ok */
@ -4745,8 +4732,7 @@ static bool check_show_access(THD *thd, TABLE_LIST *table)
test(dst_table->schema_table)))
return FALSE;
return (grant_option &&
check_grant(thd, SELECT_ACL, dst_table, 2, UINT_MAX, FALSE));
return (check_grant(thd, SELECT_ACL, dst_table, 2, UINT_MAX, FALSE));
}
default:
break;
@ -4783,8 +4769,6 @@ bool
check_table_access(THD *thd, ulong want_access,TABLE_LIST *tables,
bool no_errors)
{
uint found=0;
ulong found_access=0;
#ifndef NO_EMBEDDED_ACCESS_CHECKS
TABLE_LIST *org_tables= tables;
#endif
@ -4835,26 +4819,17 @@ check_table_access(THD *thd, ulong want_access,TABLE_LIST *tables,
tables->grant.privilege= want_access;
else if (tables->db && thd->db && strcmp(tables->db, thd->db) == 0)
{
if (found && !grant_option) // db already checked
tables->grant.privilege=found_access;
else
{
if (check_access(thd,want_access,tables->db,&tables->grant.privilege,
if (check_access(thd,want_access,tables->db,&tables->grant.privilege,
0, no_errors, test(tables->schema_table)))
goto deny; // Access denied
found_access=tables->grant.privilege;
found=1;
}
goto deny; // Access denied
}
else if (check_access(thd,want_access,tables->db,&tables->grant.privilege,
0, no_errors, test(tables->schema_table)))
goto deny;
}
thd->security_ctx= backup_ctx;
if (grant_option)
return check_grant(thd,want_access & ~EXTRA_ACL,org_tables,
return check_grant(thd,want_access & ~EXTRA_ACL,org_tables,
test(want_access & EXTRA_ACL), UINT_MAX, no_errors);
return FALSE;
deny:
thd->security_ctx= backup_ctx;
return TRUE;
@ -4884,11 +4859,10 @@ check_routine_access(THD *thd, ulong want_access,char *db, char *name,
return TRUE;
#ifndef NO_EMBEDDED_ACCESS_CHECKS
if (grant_option)
return check_grant_routine(thd, want_access, tables, is_proc, no_errors);
#endif
#else
return FALSE;
#endif
}
@ -4950,7 +4924,7 @@ bool check_some_access(THD *thd, ulong want_access, TABLE_LIST *table)
if (!check_access(thd, access, table->db,
&table->grant.privilege, 0, 1,
test(table->schema_table)) &&
!grant_option || !check_grant(thd, access, table, 0, 1, 1))
!check_grant(thd, access, table, 0, 1, 1))
DBUG_RETURN(0);
}
}
@ -6611,12 +6585,11 @@ bool multi_update_precheck(THD *thd, TABLE_LIST *tables)
else if ((check_access(thd, UPDATE_ACL, table->db,
&table->grant.privilege, 0, 1,
test(table->schema_table)) ||
grant_option &&
check_grant(thd, UPDATE_ACL, table, 0, 1, 1)) &&
(check_access(thd, SELECT_ACL, table->db,
&table->grant.privilege, 0, 0,
test(table->schema_table)) ||
grant_option && check_grant(thd, SELECT_ACL, table, 0, 1, 0)))
check_grant(thd, SELECT_ACL, table, 0, 1, 0)))
DBUG_RETURN(TRUE);
table->table_in_first_from_clause= 1;
@ -6634,7 +6607,7 @@ bool multi_update_precheck(THD *thd, TABLE_LIST *tables)
if (check_access(thd, SELECT_ACL, table->db,
&table->grant.privilege, 0, 0,
test(table->schema_table)) ||
grant_option && check_grant(thd, SELECT_ACL, table, 0, 1, 0))
check_grant(thd, SELECT_ACL, table, 0, 1, 0))
DBUG_RETURN(TRUE);
}
}
@ -6856,7 +6829,7 @@ static bool check_show_create_table_access(THD *thd, TABLE_LIST *table)
return check_access(thd, SELECT_ACL | EXTRA_ACL, table->db,
&table->grant.privilege, 0, 0,
test(table->schema_table)) ||
grant_option && check_grant(thd, SELECT_ACL, table, 2, UINT_MAX, 0);
check_grant(thd, SELECT_ACL, table, 2, UINT_MAX, 0);
}
@ -6893,7 +6866,7 @@ bool create_table_precheck(THD *thd, TABLE_LIST *tables,
(TABLE_LIST *)
lex->create_info.merge_list.first))
goto err;
if (grant_option && want_priv != CREATE_TMP_ACL &&
if (want_priv != CREATE_TMP_ACL &&
check_grant(thd, want_priv, create_table, 0, 1, 0))
goto err;

6
sql/sql_show.cc
View file

@ -706,7 +706,7 @@ bool mysqld_show_create_db(THD *thd, char *dbname,
else
db_access= (acl_get(sctx->host, sctx->ip, sctx->priv_user, dbname, 0) |
sctx->master_access);
if (!(db_access & DB_ACLS) && (!grant_option || check_grant_db(thd,dbname)))
if (!(db_access & DB_ACLS) && check_grant_db(thd,dbname))
{
my_error(ER_DBACCESS_DENIED_ERROR, MYF(0),
sctx->priv_user, sctx->host_or_ip, dbname);
@ -2649,7 +2649,7 @@ int get_all_tables(THD *thd, TABLE_LIST *tables, COND *cond)
&thd->col_access, 0, 1, with_i_schema) ||
sctx->master_access & (DB_ACLS | SHOW_DB_ACL) ||
acl_get(sctx->host, sctx->ip, sctx->priv_user, base_name,0) ||
(grant_option && !check_grant_db(thd, base_name)))
!check_grant_db(thd, base_name))
#endif
{
List<char> files;
@ -2849,7 +2849,7 @@ int fill_schema_shemata(THD *thd, TABLE_LIST *tables, COND *cond)
#ifndef NO_EMBEDDED_ACCESS_CHECKS
if (sctx->master_access & (DB_ACLS | SHOW_DB_ACL) ||
acl_get(sctx->host, sctx->ip, sctx->priv_user, file_name,0) ||
(grant_option && !check_grant_db(thd, file_name)))
!check_grant_db(thd, file_name))
#endif
{
load_db_opt_by_name(thd, file_name, &create);

2
sql/sql_update.cc
View file

@ -936,7 +936,7 @@ reopen_tables:
if (check_access(thd, want_privilege,
tl->db, &tl->grant.privilege, 0, 0,
test(tl->schema_table)) ||
(grant_option && check_grant(thd, want_privilege, tl, 0, 1, 0)))
check_grant(thd, want_privilege, tl, 0, 1, 0))
DBUG_RETURN(TRUE);
}
}

6
sql/sql_view.cc
View file

@ -322,11 +322,11 @@ bool mysql_create_view(THD *thd, TABLE_LIST *views,
*/
if ((check_access(thd, CREATE_VIEW_ACL, view->db, &view->grant.privilege,
0, 0, is_schema_db(view->db)) ||
grant_option && check_grant(thd, CREATE_VIEW_ACL, view, 0, 1, 0)) ||
check_grant(thd, CREATE_VIEW_ACL, view, 0, 1, 0)) ||
(mode != VIEW_CREATE_NEW &&
(check_access(thd, DROP_ACL, view->db, &view->grant.privilege,
0, 0, is_schema_db(view->db)) ||
grant_option && check_grant(thd, DROP_ACL, view, 0, 1, 0))))
check_grant(thd, DROP_ACL, view, 0, 1, 0))))
{
res= TRUE;
goto err;
@ -379,7 +379,7 @@ bool mysql_create_view(THD *thd, TABLE_LIST *views,
{
if (check_access(thd, SELECT_ACL, tbl->db,
&tbl->grant.privilege, 0, 0, test(tbl->schema_table)) ||
grant_option && check_grant(thd, SELECT_ACL, tbl, 0, 1, 0))
check_grant(thd, SELECT_ACL, tbl, 0, 1, 0))
{
res= TRUE;
goto err;