Re: [Maria-developers] d08860b28f3: MDEV-22374: VIEW with security definer require FILE privilege from definer not invoker in case of INTO OUTFILE

Hi, Oleksandr! On May 04, Oleksandr Byelkin wrote:

revision-id: d08860b28f3 (mariadb-5.5.67-15-gd08860b28f3) parent(s): ac2604f923f author: Oleksandr Byelkin committer: Oleksandr Byelkin timestamp: 2020-04-28 09:16:33 +0200 message:

MDEV-22374: VIEW with security definer require FILE privilege from definer not invoker in case of INTO OUTFILE

Check INTO OUTFILE clause always from invoker.

--- mysql-test/r/view_grant.result | 21 +++++++++++++++++++++ mysql-test/t/view_grant.test | 33 +++++++++++++++++++++++++++++++++ sql/sql_parse.cc | 18 +++++++++--------- 3 files changed, 63 insertions(+), 9 deletions(-)

diff --git a/mysql-test/r/view_grant.result b/mysql-test/r/view_grant.result index b2d3a0b8ca4..37dc6adc978 100644 --- a/mysql-test/r/view_grant.result +++ b/mysql-test/r/view_grant.result @@ -1587,3 +1587,24 @@ USE test; DROP DATABASE mysqltest1; DROP USER 'mysqluser1'@'%'; DROP USER 'mysqluser2'@'%'; +# +# MDEV-22374: VIEW with security definer require FILE privilege from definer +# not invoker in case of INTO OUTFILE +# +create user test@localhost; +grant select on test.* to test@localhost; +create table t1 (a int); +create definer=test@localhost sql security definer view v1 as select * from t1; +# check that ot works without view

typo "it"

+select * INTO OUTFILE '../..//tmp/test_out_txt' from t1; +# check that ot works without file

same why "//" ?

+select * from v1; +a +# rights for file should be taken from current user not view +select * INTO OUTFILE '../../tmp/test_out_txt' from (select count(*) from v1) as dv1; +select * INTO OUTFILE '../..//tmp/test_out_txt' from (select * from v1) as dv1; +select * INTO OUTFILE '../..//tmp/test_out_txt' from v1;

same

+drop view v1;

please add reverse tests too: +create sql security definer view v1 as select * from t1; +connect(con1, localhost, test); +error 1045; +select * INTO OUTFILE '../..//tmp/test_out_txt' from t1; +select * from v1; +error 1045; +select * INTO OUTFILE '../../tmp/test_out_txt' from (select count(*) from v1) as dv1; +error 1045; +select * INTO OUTFILE '../..//tmp/test_out_txt' from (select * from v1) as dv1; +error 1045; +select * INTO OUTFILE '../..//tmp/test_out_txt' from v1; +connection default;

+drop table t1; +drop user test@localhost; +# End of 5.5 tests diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc index ae5a6b4cd35..515990c879f 100644 --- a/sql/sql_parse.cc +++ b/sql/sql_parse.cc @@ -2206,15 +2206,15 @@ mysql_execute_command(THD *thd) lex->exchange != NULL implies SELECT .. INTO OUTFILE and this requires FILE_ACL access. */ - ulong privileges_requested= lex->exchange ? SELECT_ACL | FILE_ACL : - SELECT_ACL; - - if (all_tables) - res= check_table_access(thd, - privileges_requested, - all_tables, FALSE, UINT_MAX, FALSE); - else - res= check_access(thd, privileges_requested, any_db, NULL, NULL, 0, 0); + if (lex->exchange) + res= check_access(thd, FILE_ACL, any_db, NULL, NULL, 0, 0); + if (!res) + { + if (all_tables) + res= check_table_access(thd, SELECT_ACL, all_tables, FALSE, UINT_MAX, FALSE); + else + res= check_access(thd, SELECT_ACL, any_db, NULL, NULL, 0, 0); + }

No, I think this special check for a special SELECT ... INTO OUTFILE case is wrong. Why does the server even checks global privileges via views? It should not do it, I think, not for FILE not for any other global or db level privilege. I'd try something like diff --git a/sql/sql_acl.cc b/sql/sql_acl.cc --- a/sql/sql_acl.cc +++ b/sql/sql_acl.cc @@ -4699,7 +4699,7 @@ bool check_grant(THD *thd, ulong want_access, TABLE_LIST > Save a copy of the privileges without the SHOW_VIEW_ACL attribute. It will be checked during making view. */ - tl->grant.orig_want_privilege= (want_access & ~SHOW_VIEW_ACL); + tl->grant.orig_want_privilege= want_access & ~SHOW_VIEW_ACL & TABLE_ACLS; } mysql_rwlock_rdlock(&LOCK_grant); diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc --- a/sql/sql_parse.cc +++ b/sql/sql_parse.cc @@ -5204,7 +5204,8 @@ check_table_access(THD *thd, ulong requirements,TABLE_LIS> Register access for view underlying table. Remove SHOW_VIEW_ACL, because it will be checked during making view */ - table_ref->grant.orig_want_privilege= (want_access & ~SHOW_VIEW_ACL); + table_ref->grant.orig_want_privilege= + want_access & ~SHOW_VIEW_ACL & TABLE_ACLS; if (table_ref->schema_table_reformed) { Regards, Sergei VP of MariaDB Server Engineering and security@mariadb.org