The CONVERT_TZ function crashes the server when the
timezone argument is an empty SET field value.
1) The CONVERT_TZ may find a timezone string in the
tz_names hash.
2) A string representation of the empty SET is a
String of zero length with the NULL pointer.
3) If the key argument length is zero, hash functions
do comparison using the length of the record being
compared against.
I.e. a zero-length String buffer is an invalid
argument for hash search functions, and if String
points to NULL buffer, hashcmp() fails with SEGV
accessing that memory.
The my_tz_find function has been modified to
treat empty Strings as invalid timezone values
to skip unnecessary hash search.
Handle overflow when reading value from SELECT MAX(C) FROM T;
Call ha_innobase::info() after initializing the autoinc value
in ha_innobase::open().
Fix for both the builtin and plugin.
rb://402
The bug is due to a double delete of a BLOB, once via:
rollback -> btr_cur_pessimistic_delete()
and the second time via purge.
The bug is in row_upd_clust_rec_by_insert(). There we relinquish ownership
of the non-updated BLOB columns in btr_cur_mark_extern_inherited_fields()
before building the row entry that will be inserted and whose contents will
be logged in the UNDO log. However, we don't set the BLOB column later to
INHERITED so that a possible rollback will not free the original row's
non-updated BLOB entries. This is because the condition that checks for
that is in :
if (node->upd_ext) {}.
node->upd_ext is non-NULL only if a BLOB column was updated and that column
is part of some key ordering (see row_upd_replace()). This results in the
non-update BLOB columns being deleted during a rollback and subsequently by
purge again.
rb://413
A CREATE...SELECT that fails is written to the binary log if a non-transactional
statement is updated. If the logging format is ROW, the CREATE statement and the
changes are written to the binary log as distinct events and by consequence the
created table is not rolled back in the slave.
In this patch, we opted to let the slave goes out of sync by not writting to the
binary log the CREATE statement. We do this by simply reseting the binary log's
cache.
Queries may crash, if
1) the GREATEST or the LEAST function has a mixed list of
numeric and LONGBLOB arguments and
2) the result of such a function goes through an intermediate
temporary table.
An Item that references a LONGBLOB field has max_length of
UINT_MAX32 == (2^32 - 1).
The current implementation of GREATEST/LEAST returns REAL
result for a mixed list of numeric and string arguments (that
contradicts with the current documentation, this contradiction
was discussed and it was decided to update the documentation).
The max_length of such a function call was calculated as a
maximum of argument max_length values (i.e. UINT_MAX32).
That max_length value of UINT_MAX32 was used as a length for
the intermediate temporary table Field_double to hold
GREATEST/LEAST function result.
The Field_double::val_str() method call on that field
allocates a String value.
Since an allocation of String reserves an additional byte
for a zero-termination, the size of String buffer was
set to (UINT_MAX32 + 1), that caused an integer overflow:
actually, an empty buffer of size 0 was allocated.
An initialization of the "first" byte of that zero-size
buffer with '\0' caused a crash.
The Item_func_min_max::fix_length_and_dec() has been
modified to calculate max_length for the REAL result like
we do it for arithmetical operators.
******
Bug #54461: crash with longblob and union or update with subquery
Queries may crash, if
1) the GREATEST or the LEAST function has a mixed list of
numeric and LONGBLOB arguments and
2) the result of such a function goes through an intermediate
temporary table.
An Item that references a LONGBLOB field has max_length of
UINT_MAX32 == (2^32 - 1).
The current implementation of GREATEST/LEAST returns REAL
result for a mixed list of numeric and string arguments (that
contradicts with the current documentation, this contradiction
was discussed and it was decided to update the documentation).
The max_length of such a function call was calculated as a
maximum of argument max_length values (i.e. UINT_MAX32).
That max_length value of UINT_MAX32 was used as a length for
the intermediate temporary table Field_double to hold
GREATEST/LEAST function result.
The Field_double::val_str() method call on that field
allocates a String value.
Since an allocation of String reserves an additional byte
for a zero-termination, the size of String buffer was
set to (UINT_MAX32 + 1), that caused an integer overflow:
actually, an empty buffer of size 0 was allocated.
An initialization of the "first" byte of that zero-size
buffer with '\0' caused a crash.
The Item_func_min_max::fix_length_and_dec() has been
modified to calculate max_length for the REAL result like
we do it for arithmetical operators.
In order to be able to check if the set of the grouping fields in a
GROUP BY has changed (and thus to start a new group) the optimizer
caches the current values of these fields in a set of Cached_item
derived objects.
The Cached_item_str, used for caching varchar and TEXT columns,
is limited in length by the max_sort_length variable.
A String buffer to store the value with an alloced length of either
the max length of the string or the value of max_sort_length
(whichever is smaller) in Cached_item_str's constructor.
Then, at compare time the value of the string to compare to was
truncated to the alloced length of the string buffer inside
Cached_item_str.
This is all fine and valid, but only if you're not assigning
values near or equal to the alloced length of this buffer.
Because when assigning values like this the alloced length is
rounded up and as a result the next set of data will not match the
group buffer, thus leading to wrong results because of the changed
alloced_length.
Fixed by preserving the original maximum length in the
Cached_item_str's constructor and using this instead of the
alloced_length to limit the string to compare to.
Test case added.
Fix a regression (due to a typo) which caused spurious incorrect
argument errors for long data stream parameters if all forms of
logging were disabled (binary, general and slow logs).
Fix a regression (due to a typo) which caused spurious incorrect
argument errors for long data stream parameters if all forms of
logging were disabled (binary, general and slow logs).
With statement- or mixed-mode logging, "LOAD DATA INFILE" queries
are written to the binlog using special types of log events.
When mysqlbinlog reads such events, it re-creates the file in a
temporary directory with a generated filename and outputs a
"LOAD DATA INFILE" query where the filename is replaced by the
generated file. The temporary file is not deleted by mysqlbinlog
after termination.
To fix the problem, in mixed mode we go to row-based. In SBR, we
document it to remind user the tmpfile is left in a temporary
directory.
/*![:version:] Query Code */, where [:version:] is a sequence of 5
digits representing the mysql server version(e.g /*!50200 ... */),
is a special comment that the query in it can be executed on those
servers whose versions are larger than the version appearing in the
comment. It leads to a security issue when slave's version is larger
than master's. A malicious user can improve his privileges on slaves.
Because slave SQL thread is running with SUPER privileges, so it can
execute queries that he/she does not have privileges on master.
This bug is fixed with the logic below:
- To replace '!' with ' ' in the magic comments which are not applied on
master. So they become common comments and will not be applied on slave.
- Example:
'INSERT INTO t1 VALUES (1) /*!10000, (2)*/ /*!99999 ,(3)*/
will be binlogged as
'INSERT INTO t1 VALUES (1) /*!10000, (2)*/ /* 99999 ,(3)*/
The problem is that the fix Bug#29784 was mistakenly
reverted when updating YaSSL to a newer version.
The solution is to re-apply the fix and this time
actually add a meaningful test case so that possible
regressions are caught.
Problem: The functions my_like_range_xxx() returned
badly formed maximum strings for Asian character sets,
which made problems for storage engines.
Fix:
- Removed a number my_like_range_xxx() implementations,
which were in fact dumplicate code pieces.
- Using generic my_like_range_mb() instead.
- Setting max_sort_char member properly for Asian character sets
- Adding unittest/strings/strings-t.c,
to test that my_like_range_xxx() return well-formed
min and max strings.
Notes:
- No additional tests in mysql/t/ available.
Old tests cover the affected code well enough.
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.
SHOW DATABASES LIKE ... was not converting to lowercase on comparison as the
documentation is suggesting.
Fixed it to behave similarly to SHOW TABLES LIKE ... and updated the failing
on MacOSX lowercase_table2 test case.
Fix warnings flagged by the new warning option -Wunused-but-set-variable
that was added to GCC 4.6 and that is enabled by -Wunused and -Wall. The
option causes a warning whenever a local variable is assigned to but is
later unused. It also warns about meaningless pointer dereferences.
table with active trx
Essentially, the problem is that InnoDB does a implicit commit
when a cursor (table handler) is unlocked/closed, creating
a dissonance between the transaction state within the server
layer and the storage engine layer. Theoretically, a statement
transaction can encompass several table instances in a similar
manner to a multiple statement transaction, hence it does not
make sense to limit a statement transaction to the lifetime of
the table instances (cursors) used within it.
Since this particular instance of the problem is only triggerable
on 5.1 and is masked on 5.5 due 2PC being skipped (assertion is in
the prepare phase of a 2PC), the solution (which is less risky) is
to explicitly end the transaction before the cached table is unlock
on rename table.
The patch is to be null merged into trunk.
