"load data infile .." allowed for access to
unautohorized tables.
Due to a faulty if-statement it was possible to
circumvent the secure_file_priv restriction.
file .\item_subselect.cc, line 836
IN quantified predicates are never executed directly. They are rather wrapped
inside nodes called IN Optimizers (Item_in_optimizer) which take care of the
execution. However, this is not done during query preparation. Unfortunately
the LIKE predicate pre-evaluates constant right-hand side arguments even
during name resolution. Likely this is meant as an optimization.
Fixed by not pre-evaluating LIKE arguments in view prepare mode.
Back-ported to 5.0s
The user-visible problem was that changes to column-level privileges,
happened in between of PREPARE and EXECUTE of a prepared statement, were
neglected. I.e. a prepared statement could be executed with the
column-level privileges as of PREPARE-time. The problem existed for
column-level privileges only.
A similar problem existed for stored programs: the changes between
executions didn't have an effect.
Technically the thing is that table references are cached in
Prepared_statement::prepare() call. In subsequent
Prepared_statement::execute() calls those cached values are used.
There are two functions to get a field by name: find_field_in_table() and
find_field_in_table_ref(). On prepare-phase find_field_in_table_ref() is
called, on execute-phase -- find_field_in_table() because the table is
cached. find_field_in_table() does not check column-level privileges and
expects the caller to do that. The problem was that this check was
forgotten.
The fix is to check them there as it happens in find_field_in_table_ref().
Original revid: alexey.kopytov@sun.com-20100723115254-jjwmhq97b9wl932l
> Bug #54476: crash when group_concat and 'with rollup' in
> prepared statements
>
> Using GROUP_CONCAT() together with the WITH ROLLUP modifier
> could crash the server.
>
> The reason was a combination of several facts:
>
> 1. The Item_func_group_concat class stores pointers to ORDER
> objects representing the columns in the ORDER BY clause of
> GROUP_CONCAT().
>
> 2. find_order_in_list() called from
> Item_func_group_concat::setup() modifies the ORDER objects so
> that their 'item' member points to the arguments list
> allocated in the Item_func_group_concat constructor.
>
> 3. In some cases (e.g. in JOIN::rollup_make_fields) a copy of
> the original Item_func_group_concat object could be created by
> using the Item_func_group_concat::Item_func_group_concat(THD
> *thd, Item_func_group_concat *item) copy constructor. The
> latter essentially creates a shallow copy of the source
> object. Memory for the arguments array is allocated on
> thd->mem_root, but the pointers for arguments and ORDER are
> copied verbatim.
>
> What happens in the test case is that when executing the query
> for the first time, after a copy of the original
> Item_func_group_concat object has been created by
> JOIN::rollup_make_fields(), find_order_in_list() is called for
> this new object. It then resolves ORDER BY by modifying the
> ORDER objects so that they point to elements of the arguments
> array which is local to the cloned object. When thd->mem_root
> is freed upon completing the execution, pointers in the ORDER
> objects become invalid. Those ORDER objects, however, are also
> shared with the original Item_func_group_concat object which is
> preserved between executions of a prepared statement. So the
> first call to find_order_in_list() for the original object on
> the second execution tries to dereference an invalid pointer.
>
> The solution is to create copies of the ORDER objects when
> copying Item_func_group_concat to not leave any stale pointers
> in other instances with different lifecycles.
Bug#57913 large negative number to string conversion functions crash
String object which is used as result container of the item
has uninitialized 'str_charset' field. This object
might be used later to preform some internal operations
and str_charset field is involved in these operations.
It leads to crash.
The fix is to intialize str_charset in my_decimal2string() func.
--Bug#52157 various crashes and assertions with multi-table update, stored function
--Bug#54475 improper error handling causes cascading crashing failures in innodb/ndb
--Bug#57703 create view cause Assertion failed: 0, file .\item_subselect.cc, line 846
--Bug#57352 valgrind warnings when creating view
--Recently discovered problem when a nested materialized derived table is used
before being populated and it leads to incorrect result
We have several modes when we should disable subquery evaluation.
The reasons for disabling are different. It could be
uselessness of the evaluation as in case of 'CREATE VIEW'
or 'PREPARE stmt', or we should disable subquery evaluation
if tables are not locked yet as it happens in bug#54475, or
too early evaluation of subqueries can lead to wrong result
as it happened in Bug#19077.
Main problem is that if subquery items are treated as const
they are evaluated in ::fix_fields(), ::fix_length_and_dec()
of the parental items as a lot of these methods have
Item::val_...() calls inside.
We have to make subqueries non-const to prevent unnecessary
subquery evaluation. At the moment we have different methods
for this. Here is a list of these modes:
1. PREPARE stmt;
We use UNCACHEABLE_PREPARE flag.
It is set during parsing in sql_parse.cc, mysql_new_select() for
each SELECT_LEX object and cleared at the end of PREPARE in
sql_prepare.cc, init_stmt_after_parse(). If this flag is set
subquery becomes non-const and evaluation does not happen.
2. CREATE|ALTER VIEW, SHOW CREATE VIEW, I_S tables which
process FRM files
We use LEX::view_prepare_mode field. We set it before
view preparation and check this flag in
::fix_fields(), ::fix_length_and_dec().
Some bugs are fixed using this approach,
some are not(Bug#57352, Bug#57703). The problem here is
that we have a lot of ::fix_fields(), ::fix_length_and_dec()
where we use Item::val_...() calls for const items.
3. Derived tables with subquery = wrong result(Bug19077)
The reason of this bug is too early subquery evaluation.
It was fixed by adding Item::with_subselect field
The check of this field in appropriate places prevents
const item evaluation if the item have subquery.
The fix for Bug19077 fixes only the problem with
convert_constant_item() function and does not cover
other places(::fix_fields(), ::fix_length_and_dec() again)
where subqueries could be evaluated.
Example:
CREATE TABLE t1 (i INT, j BIGINT);
INSERT INTO t1 VALUES (1, 2), (2, 2), (3, 2);
SELECT * FROM (SELECT MIN(i) FROM t1
WHERE j = SUBSTRING('12', (SELECT * FROM (SELECT MIN(j) FROM t1) t2))) t3;
DROP TABLE t1;
4. Derived tables with subquery where subquery
is evaluated before table locking(Bug#54475, Bug#52157)
Suggested solution is following:
-Introduce new field LEX::context_analysis_only with the following
possible flags:
#define CONTEXT_ANALYSIS_ONLY_PREPARE 1
#define CONTEXT_ANALYSIS_ONLY_VIEW 2
#define CONTEXT_ANALYSIS_ONLY_DERIVED 4
-Set/clean these flags when we perform
context analysis operation
-Item_subselect::const_item() returns
result depending on LEX::context_analysis_only.
If context_analysis_only is set then we return
FALSE that means that subquery is non-const.
As all subquery types are wrapped by Item_subselect
it allow as to make subquery non-const when
it's necessary.
Auto increment value wraps when performing a bulk insert with
auto_increment_increment and auto_increment_offset greater than
one.
The fix:
If overflow happened then return MAX_ULONGLONG value as an
indication of overflow and check this before storing the
value into the field in update_auto_increment().
Explain fails at fix_fields stage and some items are left unfixed,
particulary Item_group_concat. Item_group_concat::orig_args field
is uninitialized in this case and Item_group_concat::print call
leads to crash.
The fix:
move the initialization of Item_group_concat::orig_args
into constructor.
assignments and comparison in query
A query that compares assignments of the same
user variable caused Valgrind warnings: access
to freed memory region.
In case of a DECIMAL argument the assignment
operator (:=) may return a pointer to a stored
value instead of its copy when evaluated.
The next assignment to the same variable may:
a) overwrite the stored value with a new one
and return the same pointer or even
b) reallocate stored value.
Thus, if we evaluate an assignment and keep
the result pointer and then evaluate another
assignment to the same variable, then the
kept result pointer of the first assignment
will point to unexpectedly changed data or
it may be a dead pointer.
That may cause wrong data or crash.
The user_var_entry::val_decimal method has
been modified to copy user variable data.
When a query fails with a different error on the slave,
the sql thread outputs a message (M) containing:
1. the error message format for the master error code
2. the master error code
3. the error message for the slave's error code
4. the slave error code
Given that the slave has no information on the error message
itself that the master outputs, it can only print its own
version of the message format (but stripped from the
additional data if the message format requires). This may
confuse users.
To fix this we augment the slave's message (M) to explicitly
state that the master's message is actually an error message
format, the one associated with the given master error code
and that the slave server knows about.
When installing plugins, there is a missing check
for slash (/) in the path on Windows. Note that on
Windows, both / and \ can be used to separate
directories.
This patch fixes the issue by:
- Adding a FN_DIRSEP symbol for all platforms
consisting of a string of legal directory
separators.
- Adding a charset-aware version of strcspn().
- Adding a check_valid_path() function that uses
my_strcspn() to check if any FN_DIRSEP character
is in the supplied string.
- Using the check_valid_path() function in
sql_plugin.cc and sql_udf.cc (which means
replacing the existing test there).
when generating new name.
If find_uniq_filename returns an error, then this error is not
being propagated upwards, and execution does not report error to
the user (although a entry in the error log is generated).
Additionally, some more errors were ignored in new_file_impl:
- when writing the rotate event
- when reopening the index and binary log file
This patch addresses this by propagating the error up in the
execution stack. Furthermore, when rotation of the binary log
fails, an incident event is written, because there may be a
chance that some changes for a given statement, were not properly
logged. For example, in SBR, LOAD DATA INFILE statement requires
more than one event to be logged, should rotation fail while
logging part of the LOAD DATA events, then the logged data would
become inconsistent with the data in the storage engine.
InnoDB AUTOINC code expects the locks to be released in strict reverse order
at the end of the statement. However, nested stored proedures and partition
tables break this rule. We now allow the locks to be deleted from the
trx->autoinc_locks vector in any order but optimise for the common (old) case.
rb://441 Approved by Marko Makela
When using BINLOG statement to execute rows log events, session variables
foreign_key_checks and unique_checks are changed temporarily. As each rows
log event has their own special session environment and its own
foreign_key_checks and unique_checks can be different from current session
which executing the BINLOG statement. But these variables are not restored
correctly after BINLOG statement. This problem will cause that the following
statements fail or generate unexpected data.
In this patch, code is added to backup and restore these two variables.
So BINLOG statement will not affect current session's variables again.
win x86 debug_max
The windows MTR run exhibited a different test execution
ordering (due to the fact that in these platforms MTR is invoked
with --parallel > 1). This uncovered a bug in the aforementioned
test case, which is triggered by the following conditions:
1. server is not restarted between two different tests;
2. the test before binlog.binlog_row_failure_mixing_engines
issues flush logs;
3. binlog.binlog_row_failure_mixing_engines uses binlog
positions to limit the output of show_binlog_events;
4. binlog.binlog_row_failure_mixing_engines does not state which
binlog file to use, thence it uses a wrong binlog file with
the correct position.
There are two possible fixes: 1. make sure that the test start
from a clean slate - binlog wise; 2. in addition to the position,
also state the binary log file before sourcing
show_binlog_events.inc .
We go for fix#1, ie, deploy a RESET MASTER before the test is
actually started.
Problem: MySQL cp1251 did not support 'U+20AC EURO SIGN'
which was assigned a few years ago to 0x88.
Fix: adding mapping: 0x88 <-> U+20AC
@ mysql-test/include/ctype_8bit.inc
New shared file to test 8bit character sets.
@ mysql-test/r/ctype_cp1251.result
@ mysql-test/t/ctype_cp1251.test
Adding tests
@ sql/share/charsets/cp1251.xml
Adding mapping
@ strings/ctype-extra.c
Regenerating ctype-extra.c using strings/conf_to_src
according to new cp1251.xml
