but we have nevertheless exposed them to users via pg_get_expr(). It would
be too much maintenance effort to rigorously check the input, so put a hack
in place instead to restrict pg_get_expr() so that the argument must come
from one of the system catalog columns known to contain valid expressions.
Per report from Rushabh Lathia. Backpatch to 7.4 which is the oldest
supported version at the moment.
In HEAD, emit a warning when an operator named => is defined.
In both HEAD and the backbranches (except in 8.2, where contrib
modules do not have documentation), document that hstore's text =>
text operator may be removed in a future release, and encourage the
use of the hstore(text, text) function instead. This function only
exists in HEAD (previously, it was called tconvert), so backpatch
it back to 8.2, when hstore was added. Per discussion.
columns correctly. In passing, get rid of some dead logic in the
underlying get_sql_insert() etc functions --- there is no caller that
will pass null value-arrays to them.
Per bug report from Robert Voinea.
dblink_build_sql_insert() and related functions. In particular, be sure to
reject references to dropped and out-of-range column numbers. The numbers
are still interpreted as physical column numbers, though, for backward
compatibility.
This patch replaces Joe's patch of 2010-02-03, which handled only some aspects
of the problem.
lock the target relation just once per SQL function call. The original coding
obtained and released lock several times per call. Aside from saving a
not-insignificant number of cycles, this eliminates possible race conditions
if someone tries to modify the relation's schema concurrently. Also
centralize locking and permission-checking logic.
Problem noted while investigating a trouble report from Robert Voinea --- his
problem is still to be fixed, though.
This saves cycles in get_ps_display() on many popular platforms, and more
importantly ensures that get_ps_display() will correctly return an empty
string if init_ps_display() hasn't been called yet. Per trouble report
from Ray Stell, in which log_line_prefix %i produced junk early in backend
startup.
Back-patch to 8.0. 7.4 doesn't have %i and its version of get_ps_display()
makes no pretense of avoiding pad junk anyhow.
Asia/Novosibirsk on Windows.
Microsoft changed the behaviour of this zone in the timezone update
from KB976098. The zones differ in handling of DST, and the old
zone was just removed.
Noted by Dmitry Funk
that is a regular table or view owned by a superuser. This prevents a
trojan horse attack whereby any unprivileged SQL user could create such a
table and insert code into it that would then get executed in other users'
sessions whenever they call pltcl functions.
Worse yet, because the code was automatically loaded into both the "normal"
and "safe" interpreters at first use, the attacker could execute unrestricted
Tcl code in the "normal" interpreter without there being any pltclu functions
anywhere, or indeed anyone else using pltcl at all: installing pltcl is
sufficient to open the hole. Change the initialization logic so that the
"unknown" code is only loaded into an interpreter when the interpreter is
first really used. (That doesn't add any additional security in this
particular context, but it seems a prudent change, and anyway the former
behavior violated the principle of least astonishment.)
Security: CVE-2010-1170
fundamentally insecure. Instead apply an opmask to the whole interpreter that
imposes restrictions on unsafe operations. These restrictions are much harder
to subvert than is Safe.pm, since there is no container to be broken out of.
Backported to release 7.4.
In releases 7.4, 8.0 and 8.1 this also includes the necessary backporting of
the two interpreters model for plperl and plperlu adopted in release 8.2.
In versions 8.0 and up, the use of Perl's POSIX module to undo its locale
mangling on Windows has become insecure with these changes, so it is
replaced by our own routine, which is also faster.
Nice side effects of the changes include that it is now possible to use perl's
"strict" pragma in a natural way in plperl, and that perl's $a and
$b variables now work as expected in sort routines, and that function
compilation is significantly faster.
Tim Bunce and Andrew Dunstan, with reviews from Alex Hunsaker and
Alexey Klyukin.
Security: CVE-2010-1169
Depending on which spec you read, field widths and precisions in %s may be
counted either in bytes or characters. Our code was assuming bytes, which
is wrong at least for glibc's implementation, and in any case libc might
have a different idea of the prevailing encoding than we do. Hence, for
portable results we must avoid using anything more complex than just "%s"
unless the string to be printed is known to be all-ASCII.
This patch fixes the cases I could find, including the psql formatting
failure reported by Hernan Gonzalez. In HEAD only, I also added comments
to some places where it appears safe to continue using "%.*s".
refers to itself (directly or indirectly). Instead, print a message when
recursion is detected, and don't expand the repeated reference. Per bug
#5448 from Francis Markham.
Back-patch to 8.0. Although the issue exists in 7.4 as well, it seems
impractical to fix there because of the lack of any state stack that
could be used to track active expansions.
returns EINVAL for an existing shared memory segment. Although it's not
terribly sensible, that behavior does meet the POSIX spec because EINVAL
is the appropriate error code when the existing segment is smaller than the
requested size, and the spec explicitly disclaims any particular ordering of
error checks. Moreover, it does in fact happen on OS X and probably other
BSD-derived kernels. (We were able to talk NetBSD into changing their code,
but purging that behavior from the wild completely seems unlikely to happen.)
We need to distinguish collision with a pre-existing segment from invalid size
request in order to behave sensibly, so it's worth some extra code here to get
it right. Per report from Gavin Kistner and subsequent investigation.
Back-patch to all supported versions, since any of them could get used
with a kernel having the debatable behavior.
memory if the result had zero rows, and also if there was any sort of error
while converting the result tuples into Python data. Reported and partially
fixed by Andres Freund.
Back-patch to all supported versions. Note: I haven't tested the 7.4 fix.
7.4's configure check for python is so obsolete it doesn't work on my
current machines :-(. The logic change is pretty straightforward though.
reload and rotation signals, and a helper thread reads messages from the
pipe and writes them to the log file. However, server code isn't generally
thread-safe, so if both try to do e.g palloc()/pfree() at the same time,
bad things will happen. To fix that, use a critical section (which is like
a mutex) to enforce that only one the threads are active at a time.
the SELECT query in \copy (SELECT ...) commands. This is unnecessary and
breaks numeric literals, as seen in bug #5411 from Vitalii Tymchyshyn.
This change has already been made in passing in HEAD; backpatch to 8.2
through 8.4 (earlier releases don't have COPY (SELECT ...) at all).
relcache reload works. In the patched code, a relcache entry in process of
being rebuilt doesn't get unhooked from the relcache hash table; which means
that if a cache flush occurs due to sinval queue overrun while we're
rebuilding it, the entry could get blown away by RelationCacheInvalidate,
resulting in crash or misbehavior. Fix by ensuring that an entry being
rebuilt has positive refcount, so it won't be seen as a target for removal
if a cache flush occurs. (This will mean that the entry gets rebuilt twice
in such a scenario, but that's okay.) It appears that the problem can only
arise within a transaction that has previously reassigned the relfilenode of
a pre-existing table, via TRUNCATE or a similar operation. Per bug #5412
from Rusty Conover.
Back-patch to 8.2, same as the patch that introduced the problem.
I think that the failure can't actually occur in 8.2, since it lacks the
rd_newRelfilenodeSubid optimization, but let's make it work like the later
branches anyway.
Patch by Heikki, slightly editorialized on by me.
Windows timezone name where the information in the registry is
incomplete, instead of aborting.
This fixes cases when the registry information is incomplete for
a timezone that is alphabetically before the one that is in use.
Per report from Alexander Forschner
Windows, thanks to a feature in CRT called Parameter Validation.
Backpatch to 8.2, which is the oldest version supported on Windows. In
8.2 and 8.3 also backpatch the earlier change to use DEVNULL instead of
NULL_DEV #define for a /dev/null-like device. NULL_DEV was hard-coded to
"/dev/null" regardless of platform, which didn't work on Windows, while
DEVNULL works on all platforms. Restarting syslogger didn't work on
Windows on versions 8.3 and below because of that.
by a superuser -- "ALTER USER f RESET setting" already disallows removing such a
setting.
Apply the same treatment to ALTER DATABASE d RESET ALL when run by a database
owner that's not superuser.
so that we won't try to attach any context printouts to messages that get
emitted while exiting. Per report from Dennis Koegel, the context functions
won't necessarily work after we've started shutting down the backend, and it
seems possible that debug_query_string could be pointing at freed storage
as well. The context information doesn't seem particularly relevant to
such messages anyway, so there's little lost by suppressing it.
Back-patch to all supported branches. I can only demonstrate a crash with
log_disconnections messages back to 8.1, but the risk seems real in 8.0 and
before anyway.
The latter is considered unwarranted chumminess with the implementation,
and can lead to crashes with recent Perl versions.
Report and fix by Tim Bunce. Back-patch to all versions containing the
questionable coding pattern.
--single-transaction are both used and the failure happens in commit,
e.g. failed deferred trigger. Also properly free BEGIN/COMMIT result
structures from --single-transaction.
Per report from Dominic Bevacqua
