Non-definer of a view was allowed to alter that view. Due to this the alterer
can elevate his access rights to access rights of the view definer and thus
modify data which he wasn't allowed to modify. A view defined with
SQL SECURITY INVOKER can't be used directly for access rights elevation.
But a user can first alter the view SQL code and then alter the view to
SQL SECURITY DEFINER and thus elevate his access rights. Due to this
altering a view with SQL SECURITY INVOKER is also prohibited.
Now the mysql_create_view function allows ALTER VIEW only to the view
definer or a super user.
causes full table lock on innodb table.
Also fixes Bug#28502 Triggers that update another innodb table
will block on X lock unnecessarily (duplciate).
Code review fixes.
Both bugs' synopses are misleading: InnoDB table is
not X locked. The statements, however, cannot proceed concurrently,
but this happens due to lock conflicts for tables used in triggers,
not for the InnoDB table.
If a user had an InnoDB table, and two triggers, AFTER UPDATE and
AFTER INSERT, competing for different resources (e.g. two distinct
MyISAM tables), then these two triggers would not be able to execute
concurrently. Moreover, INSERTS/UPDATES of the InnoDB table would
not be able to run concurrently.
The problem had other side-effects (see respective bug reports).
This behavior was a consequence of a shortcoming of the pre-locking
algorithm, which would not distinguish between different DML operations
(e.g. INSERT and DELETE) and pre-lock all the tables
that are used by any trigger defined on the subject table.
The idea of the fix is to extend the pre-locking algorithm to keep track,
for each table, what DML operation it is used for and not
load triggers that are known to never be fired.
ALTER VIEW is currently not supported as a prepared statement
and should be disabled as such as they otherwise could cause server crashes.
ALTER VIEW is currently not supported when called from stored
procedures or functions for related reasons and should also be disabled.
This patch disables these DDL statements and adjusts the appropriate test
cases accordingly.
Additional tests has been added to reflect on the fact that we do support
CREATE/ALTER/DROP TABLE for Prepared Statements (PS), Stored Procedures (SP)
and PS within SP.
When the same VIEW was created at the master side twice,
malformed (truncated after the word 'AS') query string
was forwarded to client side, so error messages on the
master and client was different, and replication was
broken.
The mysql_register_view function call failed
too early: fields of `view' output argument of this
function was not filled yet with correct data required
for query replication.
The mysql_register_view function also copied pointers to
local buffers into a memory allocated by the caller.
The root cause of this bug is related to the function skip_rear_comments,
in sql_lex.cc
Recent code changes in skip_rear_comments changed the prototype from
"const uchar*" to "const char*", which had an unforseen impact on this test:
(endp[-1] < ' ')
With unsigned characters, this code filters bytes of value [0x00 - 0x20]
With *signed* characters, this also filters bytes of value [0x80 - 0xFF].
This caused the regression reported, considering cyrillic characters in the
parameter name to be whitespace, and truncated.
Note that the regression is present both in 5.0 and 5.1.
With this fix:
- [0x80 - 0xFF] bytes are no longer considered whitespace.
This alone fixes the regression.
In addition, filtering [0x00 - 0x20] was found bogus and abusive,
so that the code now filters uses my_isspace when looking for whitespace.
Note that this fix is only addressing the regression affecting UTF-8
in general, but does not address a more fundamental problem with
skip_rear_comments: parsing a string *backwards*, starting at end[-1],
is not safe with multi-bytes characters, so that end[-1] can confuse the
last byte of a multi-byte characters with a characters to filter out.
The only known impact of this remaining issue affects objects that have to
meet all the conditions below:
- the object is a FUNCTION / PROCEDURE / TRIGGER / EVENT / VIEW
- the body consist of only *1* instruction, and does *not* contain a
BEGIN-END block
- the instruction ends, lexically, with <ident> <whitespace>* ';'?
For example, "select <ident>;" or "return <ident>;"
- The last character of <ident> is a multi-byte character
- the last byte of this character is ';' '*', '/' or whitespace
In this case, the body of the object will be truncated after parsing,
and stored in an invalid format.
This last issue has not been fixed in this patch, since the real fix
will be implemented by Bug 25411 (trigger code truncated), which is caused
by the very same code.
The real problem is that the function skip_rear_comments is only a
work-around, and should be removed entirely: see the proposed patch for
bug 25411 for details.
The issue found with bug 25411 is due to the function skip_rear_comments()
which damages the source code while implementing a work around.
The root cause of the problem is in the lexical analyser, which does not
process special comments properly.
For special comments like :
[1] aaa /*!50000 bbb */ ccc
since 5.0 is a version older that the current code, the parser is in lining
the content of the special comment, so that the query to process is
[2] aaa bbb ccc
However, the text of the query captured when processing a stored procedure,
stored function or trigger (or event in 5.1), can be after rebuilding it:
[3] aaa bbb */ ccc
which is wrong.
To fix bug 25411 properly, the lexical analyser needs to return [2] when
in lining special comments.
In order to implement this, some preliminary cleanup is required in the code,
which is implemented by this patch.
Before this change, the structure named LEX (or st_lex) contains attributes
that belong to lexical analysis, as well as attributes that represents the
abstract syntax tree (AST) of a statement.
Creating a new LEX structure for each statements (which makes sense for the
AST part) also re-initialized the lexical analysis phase each time, which
is conceptually wrong.
With this patch, the previous st_lex structure has been split in two:
- st_lex represents the Abstract Syntax Tree for a statement. The name "lex"
has not been changed to avoid a bigger impact in the code base.
- class lex_input_stream represents the internal state of the lexical
analyser, which by definition should *not* be reinitialized when parsing
multiple statements from the same input stream.
This change is a pre-requisite for bug 25411, since the implementation of
lex_input_stream will later improve to deal properly with special comments,
and this processing can not be done with the current implementation of
sp_head::reset_lex and sp_head::restore_lex, which interfere with the lexer.
This change set alone does not fix bug 25411.
When merging views into the enclosing statement
the ORDER BY clause of the view is merged to the
parent's ORDER BY clause.
However when the VIEW is merged into an UNION
branch the ORDER BY should be ignored.
Use of ORDER BY for individual SELECT statements
implies nothing about the order in which the rows
appear in the final result because UNION by default
produces unordered set of rows.
Fixed by ignoring the ORDER BY clause from the merge
view when expanded in an UNION branch.
another user.
When the DEFINER clause isn't specified in the ALTER statement then it's loaded
from the view definition. If the definer differs from the current user then
the error is thrown because only a super-user can set other users as a definers.
Now if the DEFINER clause is omitted in the ALTER VIEW statement then the
definer from the original view is used without check.
on a database.
The problem was that we required not less privileges on the base tables
than we have on the view.
The fix is to be more flexible and allow to create such a view (necessary
privileges will be checked at the runtime).
The problem was that if a prepared statement accessed a view, the
access to the tables listed in the query after that view was done in
the security context of the view.
The bug was in the assigning of the security context to the tables
belonging to a view: we traversed the list of all query tables
instead. It didn't show up in the normal (non-prepared) statements
because of the different order of the steps of checking privileges
and descending into a view for normal and prepared statements.
The solution is to traverse the list and stop once the last table
belonging to the view was processed.
- Removed not used variables and functions
- Added #ifdef around code that is not used
- Renamed variables and functions to avoid conflicts
- Removed some not used arguments
Fixed some class/struct warnings in ndb
Added define IS_LONGDATA() to simplify code in libmysql.c
I did run gcov on the changes and added 'purecov' comments on almost all lines that was not just variable name changes
Fixed compiler warnings (detected by VC++):
- Removed not used variables
- Added casts
- Fixed wrong assignments to bool
- Fixed wrong calls with bool arguments
- Added missing argument to store(longlong), which caused wrong store method to be called.
(Mostly in DBUG_PRINT() and unused arguments)
Fixed bug in query cache when used with traceing (--with-debug)
Fixed memory leak in mysqldump
Removed warnings from mysqltest scripts (replaced -- with #)
warnings in sql_trigger.cc and sql_view.cc".
According to the current version of C++ standard offsetof() macro
can't be used for non-POD types. So warnings were emitted when we
tried to use this macro for TABLE_LIST and Table_triggers_list
classes. Note that despite of these warnings it was probably safe
thing to do.
This fix tries to circumvent this limitation by implementing
custom version of offsetof() macro to be used with these
classes. This hack should go away once we will refactor
File_parser class.
Alternative approaches such as disabling this warning for
sql_trigger.cc/sql_view.cc or for the whole server were
considered less explicit. Also I was unable to find a way
to disable particular warning for particular _part_ of
file in GCC.
should fail to create
The problem was that this type of errors was checked during view
creation, which doesn't happen when CREATE VIEW is a statement of
a created stored routine.
The solution is to perform the checks at parse time. The idea of the
fix is that the parser checks if a construction just parsed is allowed
in current circumstances by testing certain flags, and this flags are
reset for VIEWs.
The side effect of this change is that if the user already have
such bogus routines, it will now get a error when trying to do
SHOW CREATE PROCEDURE proc;
(and some other) and when trying to execute such routine he will get
ERROR 1457 (HY000): Failed to load routine test.p5. The table mysql.proc is missing, corrupt, or contains bad data (internal code -6)
However there should be very few such users (if any), and they may
(and should) drop these bogus routines.
(race cond)
It was possible for one thread to interrupt a Data Definition Language
statement and thereby get messages to the binlog out of order. Consider:
Connection 1: Drop Foo x
Connection 2: Create or replace Foo x
Connection 2: Log "Create or replace Foo x"
Connection 1: Log "Drop Foo x"
Local end would have Foo x, but the replicated slaves would not.
The fix for this is to wrap all DDL and logging of a kind in the same mutex.
Since we already use mutexes for the various parts of altering the server,
this only entails moving the logging events down close to the action, inside
the mutex protection.
On an INSERT into an updatable but non-insertable view an error message was
issued stating the view being not updatable. This can lead to a confusion of a
user.
A new error message is introduced. Is is showed when a user tries to insert
into a non-insertable view.
When a view was used inside a trigger or a function, lock type for
tables used in a view was always set to READ (thus making the view
non-updatable), even if we were trying to update the view.
The solution is to set lock type properly.
