The change from MDEV-29465 exposed a flaw in replace_column_table
where again we were not properly updating the column-level bits.
replace_table_table was changed in MDEV-29465 to properly update
grant_table->init_cols, however replace_column_table still only
modified grant_column->rights when the GRANT_COLUMN already existed.
This lead to a missmatch between GRANT_COLUMN::init_rights and
GRANT_COLUMN::rights, *if* the GRANT_COLUMN already existed.
As an example:
GRANT SELECT (col1) ...
Here:
For col1
GRANT_COLUMN::init_rights and GRANT_COLUMN::rights are set to 1 (SELECT) in
replace_column_table.
GRANT INSERT (col1) ...
Here, without this patch GRANT_COLUMN::init_rights is still 1 and
GRANT_COLUMN::rights is 3 (SELECT_PRIV | INSERT_PRIV)
Finally, if before this patch, one does:
REVOKE SELECT (col1) ...
replace_table_table will see that init_rights loses bit 1 thus it
considers there are no more rights granted on that particular table.
This prompts the whole GRANT_TABLE to be removed via the first revoke,
when the GRANT_COLUMN corresponding to it should still have init_rights == 2.
By also updating replace_column_table to keep init_rights in sync
properly, the issue is resolved.
Reviewed by <serg@mariadb.com>
OpenSSL handles memory management using **OPENSSL_xxx** API[^1]. For
allocation, there is `OPENSSL_malloc`. To free it, `OPENSSL_free` should
be called.
We've been lucky that OPENSSL (and wolfSSL)'s implementation allowed the
usage of `free` for memory cleanup. However, other OpenSSL forks, such
as AWS-LC[^2], is not this forgiving. It will cause a server crash.
Test case `openssl_1` provides good coverage for this issue. If a user
is created using:
`grant select on test.* to user1@localhost require SUBJECT "...";`
user1 will crash the instance during connection under AWS-LC.
There have been numerous OpenSSL forks[^3]. Due to FIPS[^4] and other
related regulatory requirements, MariaDB will be built using them. This
fix will increase MariaDB's adaptability by using more compliant and
generally accepted API.
All new code of the whole pull request, including one or several files
that are either new files or modified ones, are contributed under the
BSD-new license. I am contributing on behalf of my employer Amazon Web
Services, Inc.
[^1]: https://www.openssl.org/docs/man1.1.1/man3/OPENSSL_malloc.html
[^2]: https://github.com/awslabs/aws-lc
[^3]: https://en.wikipedia.org/wiki/OpenSSL#Forks
[^4]: https://en.wikipedia.org/wiki/FIPS_140-2
- Added missing information about database of corresponding table for various types of commands
- Update some typos
- Reviewed by: <vicentiu@mariadb.org>
The issue manifests due to a bug in mysql_routine_grant. This was a side
effect of e46eea8660 which fixed the problem of not giving appropriate error
message (ER_NONEXISTING_PROC_GRANT) when a routine grant existed due to role
inheritance.
When granting a routine privilege, it is possible to have a GRANT_NAME
entry already created from an inherited role, but with it's init_privs
set to 0.
In this case we must not create a *new* grant entry, but we must edit
this grant entry to set its init_privs.
Note that this case was already covered by MDEV-29458, however due to a
forgotten "flush privileges;" the actual code path never got hit.
Remove the flush privilege command as it was never intended to be there
in the first place.
There was an issue in updating in-memory role datastructures when
propagating role grants.
The issue is that changing a particular role's privilege (on any
privilege level, global, database, etc.)
was done such that it overwrote the entire set of bits for that
particular level of privileges.
For example:
grant select on *.* to r1 -> sets the access bits to r1 to select,
regardless of what bits were present for role r1 (inherited from any
other roles).
Before this fix, the rights of role r1 were propagated to any roles r1
was granted to, however the propagated rights did *not* include the
complete rights r1 inherited from its own grants.
For example:
grant r2 to r1;
grant select on *.* to r2;
grant insert on *.* to r1; # This command completely disregards the
# select privilege from r2.
In order to correct this, ensure that before rights are propagated
onwards, that the current's role rights have been updated from its
grants.
Additionally, the patch exposed a flaw in the DROP ROLE code.
When deleting a role we removed all its previous grants, but what
remained was the actual links of roles granted to the dropped role.
Having these links present when propagating grants meant that we would
have leftover ACL_xxx entries.
Ensure that the links are removed before propagating grants.
There was a bug in the ACL internal data structures GRANT_TABLE and
GRANT_COLUMN. The semantics are: GRANT_TABLE::init_cols and
GRANT_COLUMN::init_privs represent the bits that correspond to the
privilege bits stored in the physical tables. The other struct members
GRANT_TABLE::cols and GRANT_COLUMN::privs represent the actual access
bits, as they may be modified through role grants.
The error in logic was mixing the two fields and thus we ended up
storing the logical access bits in the physical tables, instead of the
physical (init_xxx) bits.
This caused subsequent DBUG_ASSERT failures when dropping the involved
roles.
Problem:
========
Replication can break while applying a query log event if its
respective command errors on the primary, but is ignored by the
replication filter within Grant_tables on the replica. The bug
reported by MDEV-28530 shows this with REVOKE ALL PRIVILEGES using a
non-existent user. The primary will binlog the REVOKE command with
an error code, and the replica will think the command executed with
success because the replication filter will ignore the command while
accessing the Grant_tables classes. When the replica performs an
error check, it sees the difference between the error codes, and
replication breaks.
Solution:
========
If the replication filter check done by Grant_tables logic ignores
the tables, reset thd->slave_expected_error to 0 so that
Query_log_event::do_apply_event() can be made aware that the
underlying query was ignored when it compares errors.
Note that this bug also effects DROP USER if not all users exist
in the provided list, and the patch fixes and tests this case.
Reviewed By:
============
andrei.elkin@mariadb.com
Problem:
========
When replicating SET DEFAULT ROLE, the pre-update check (i.e. that
in set_var_default_role::check()) tries to validate the existence of
the given rules/user even when the targeted tables are ignored. When
previously issued CREATE USER/ROLE commands are ignored by the
replica because of the replication filtering rules, this results in
an error because the targeted data does not exist.
Solution:
========
Before checking that the given roles/user exist of a SET DEFAULT
ROLE command, first ensure that the mysql.user and
mysql.roles_mapping tables are not excluded by replication filters.
Reviewed By:
============
Andrei Elkin <andrei.elkin@mariadb.com>
Sergei Golubchik <serg@mariadb.com>
This happens upon CREATE USER and DROP ROLE.
The underlying problem is that our HASH implementation shuffles elements
around when performing an update or delete. This means that when doing a
scan through the HASH table by index, in search of elements to delete or
update one must restart the scan to make sure nothing is missed if at least
one delete / update happened.
More specifically, what happened in this case:
The hash has 131 element, DROP ROLE removes the element
[119]. Its [119]->next was element [129], so [129] is moved to [119].
Now we need to compact the hash, removing the last element [130]. It
gets one bit off its hash value and becomes element [2]. The existing
element [2] is moved to [129], and old [130] is moved to [2].
We cannot simply move [130] to [129] and make [2]->next=130, it won't
work if [2] is itself in the collision list and doesn't belong in [2].
The handle_grant_struct code assumed that it is safe to continue by only
reexamining the currently modified / deleted element index, but that is
not true.
Missing to delete an element in the hash triggered the assertion in
the test case. DROP ROLE would not clear all necessary role->role or
role->user mappings.
To fix the problem we ensure that the scan is restarted, only if an
element was deleted / updated, similar to how bubble-sort keeps sorting
until it finds no more elements to swap.
The code erroneously used buff[100] in a fiew places to make
a GRANTEE value in the form:
'user'@'host'
Fix:
- Fixing the code to use (USER_HOST_BUFF_SIZE + 6) instead of 100.
- Adding a DBUG_ASSERT to make sure the buffer is enough
- Wrapping the code into a class Grantee_str, to reuse it easier in 4 places.
- `SET DEFAULT ROLE xxx [FOR yyy]` should say:
"User yyy has not been granted a role xxx" if:
- The current user (not the user `yyy` in the FOR clause) can see the
role xxx. It can see the role if:
* role exists in `mysql.roles_mappings` (traverse the graph),
* If the current user has read access on `mysql.user` table - in
that case, it can see all roles, granted or not.
- Otherwise it should be "Invalid role specification".
In other words, it should not be possible to use `SET DEFAULT ROLE` to discover whether a specific role exist or not.
- Any temporary tables created under read-only mode will never be logged
to binary log. Any usage of these tables to update normal tables, even
after read-only has been disabled, will use row base logging (as the
temporary table will not be on the slave).
- Analyze, check and repair table will not be logged in read-only mode.
Other things:
- Removed not used varaibles in
MYSQL_BIN_LOG::flush_and_set_pending_rows_event.
- Set table_share->table_creation_was_logged for all normal tables.
- THD::binlog_query() now returns -1 if statement was not logged., This
is used to update table_share->table_creation_was_logged.
- Don't log admin statements in opt_readonly is set.
- Table's that doesn't have table_creation_was_logged will set binlog format to row
logging.
- Removed not needed/wrong setting of table->s->table_creation_was_logged
in create_table_from_items()
