array_set_element() and related functions allow an array to be
enlarged by assigning to subscripts outside the current array bounds.
While these places were careful to check that the new bounds are
allowable, they neglected to consider the risk of integer overflow
in computing the new bounds. In edge cases, we could compute new
bounds that are invalid but get past the subsequent checks,
allowing bad things to happen. Memory stomps that are potentially
exploitable for arbitrary code execution are possible, and so is
disclosure of server memory.
To fix, perform the hazardous computations using overflow-detecting
arithmetic routines, which fortunately exist in all still-supported
branches.
The test cases added for this generate (after patching) errors that
mention the value of MaxArraySize, which is platform-dependent.
Rather than introduce multiple expected-files, use psql's VERBOSITY
parameter to suppress the printing of the message text. v11 psql
lacks that parameter, so omit the tests in that branch.
Our thanks to Pedro Gallegos for reporting this problem.
Security: CVE-2023-5869
This avoids a compiler bug occurring in AIX's xlc, even in pretty
late-model revisions. Buildfarm testing has now confirmed that
only 64-bit xlc is affected. Although we are contemplating
dropping support for xlc in v17, it's still supported in the
back branches, so we need this fix.
Back-patch of code changes from HEAD commit 19fa97731.
(The test cases were already back-patched, in 4a427b82c et al.)
Discussion: https://postgr.es/m/CA+hUKGK=DOC+hE-62FKfZy=Ybt5uLkrg3zCZD-jFykM-iPn8yw@mail.gmail.com
Under interval_ops, some equal values are distinguishable. One such
pair is '24:00:00' and '1 day'. With that being so, btequalimage()
breaches the documented contract for the "equalimage" btree support
function. This can cause incorrect results from index-only scans.
Users should REINDEX any btree indexes having interval-type columns.
After updating, pg_amcheck will report an error for almost all such
indexes. This fix makes interval_ops simply omit the support function,
like numeric_ops does. Back-pack to v13, where btequalimage() first
appeared. In back branches, for the benefit of old catalog content,
btequalimage() code will return false for type "interval". Going
forward, back-branch initdb will include the catalog change.
Reviewed by Peter Geoghegan.
Discussion: https://postgr.es/m/20231011013317.22.nmisch@google.com
After receiving position data for a lexeme, tsvectorrecv()
advanced its "datalen" value by (npos+1)*sizeof(WordEntry)
where the correct calculation is (npos+1)*sizeof(WordEntryPos).
This accidentally failed to render the constructed tsvector
invalid, but it did result in leaving some wasted space
approximately equal to the space consumed by the position data.
That could have several bad effects:
* Disk space is wasted if the received tsvector is stored into a
table as-is.
* A legal tsvector could get rejected with "maximum total lexeme
length exceeded" if the extra space pushes it over the MAXSTRPOS
limit.
* In edge cases, the finished tsvector could be assigned a length
larger than the allocated size of its palloc chunk, conceivably
leading to SIGSEGV when the tsvector gets copied somewhere else.
The odds of a field failure of this sort seem low, though valgrind
testing could probably have found this.
While we're here, let's express the calculation as
"sizeof(uint16) + npos * sizeof(WordEntryPos)" to avoid the type
pun implicit in the "npos + 1" formulation. It's not wrong
given that WordEntryPos had better be 2 bytes to avoid padding
problems, but it seems clearer this way.
Report and patch by Denis Erokhin. Back-patch to all supported
versions.
Discussion: https://postgr.es/m/009801d9f2d9$f29730c0$d7c59240$@datagile.ru
cursor_to_xmlschema() assumed that any Portal must have a tupDesc,
which is not so. Add a defensive check.
It's plausible that this mistake occurred because of the rather
poorly chosen name of the lookup function SPI_cursor_find(),
which in such cases is returning something that isn't very much
like a cursor. Add some documentation to try to forestall future
errors of the same ilk.
Report and patch by Boyu Yang (docs changes by me). Back-patch
to all supported branches.
Discussion: https://postgr.es/m/dd343010-c637-434c-a8cb-418f53bda3b8.yangboyu.yby@alibaba-inc.com
expandRecordVariable() failed to adjust the parse nesting structure
correctly when recursing to inspect an outer-level Var. This could
result in assertion failures or core dumps in corner cases.
Likewise, get_name_for_var_field() failed to adjust the deparse
namespace stack correctly when recursing to inspect an outer-level
Var. In this case the likely result was a "bogus varno" error
while deparsing a view.
Per bug #18077 from Jingzhou Fu. Back-patch to all supported
branches.
Richard Guo, with some adjustments by me
Discussion: https://postgr.es/m/18077-b9db97c6e0ab45d8@postgresql.org
This could lead to an imprecise choice when splitting an index page of a
GiST index on a tsvector, deciding which entries should remain on the
old page and which entries should move to a new page.
This is wrong since tsearch2 has been moved into core with commit
140d4ebcb4, so backpatch all the way down. This error has been
spotted by valgrind.
Author: Alexander Lakhin
Discussion: https://postgr.es/m/17950-6c80a8d2b94ec695@postgresql.org
Backpatch-through: 11
This was failing for queries which try to get the .type() of a
jpiLikeRegex. For example:
select jsonb_path_query('["string", "string"]',
'($[0] like_regex ".{7}").type()');
Reported-by: Alexander Kozhemyakin
Bug: #18035
Discussion: https://postgr.es/m/18035-64af5cdcb5adf2a9@postgresql.org
Backpatch-through: 12, where SQL/JSON path was added.
Commit 927d9abb6 purported to make datetime() accept any string
that could be output for a datetime value by to_jsonb(). But it
overlooked the possibility of fractional seconds being present,
so that cases as simple as to_jsonb(now()) would defeat it.
Fix by adding formats that include ".US" to the list in
executeDateTimeMethod(). (Note that while this is nominally
microseconds, it'll do the right thing for fractions with
fewer than six digits.)
In passing, re-order the list to restore the datatype ordering
specified in its comment. The violation accidentally did not
break anything; but the next edit might be less lucky, so add
more comments.
Per report from Tim Field. Back-patch to v13 where datetime()
was added, like the previous patch.
Discussion: https://postgr.es/m/014A028B-5CE6-4FDF-AC24-426CA6FC9CEE@mohiohio.com
Non-leaf pages of GiST indexes contain key attributes, leaf pages
contain both key and non-key attributes, and gist_page_items() ignored
the handling of non-key attributes. This caused a few problems when
using gist_page_items() on a GiST index with INCLUDE:
- On a non-leaf page, the function would crash.
- On a leaf page, the function would work, but miss to display all the
values for included attributes.
This commit fixes gist_page_items() to handle such cases in a more
appropriate way, and now displays the values of key and non-key
attributes for each item separately in a style consistent with what
ruleutils.c would generate for the attribute list, depending on the page
type dealt with. In a way similar to how a record is displayed, values
would be double-quoted for key or non-key attributes if required.
ruleutils.c did not provide a routine able to control if non-key
attributes should be displayed, so an extended() routine for index
definitions is added to work around the leaf and non-leaf page
differences.
While on it, this commit fixes a third problem related to the amount of
data reported for key attributes. The code originally relied on
BuildIndexValueDescription() (used for error reports on constraints)
that would not print all the data stored in the index but the index
opclass's input type, so this limited the amount of information
available. This switch makes gist_page_items() much cheaper as there is
no need to run ACL checks for each item printed, which is not an issue
anyway as superuser rights are required to execute the functions of
pageinspect. Opclasses whose data cannot be displayed can rely on
gist_page_items_bytea().
The documentation of this function was slightly incorrect for the
output results generated on HEAD and v15, so adjust it on these
branches.
Author: Alexander Lakhin, Michael Paquier
Discussion: https://postgr.es/m/17884-cb8c326522977acb@postgresql.org
Backpatch-through: 14
These functions incautiously fetched the array's first lower bound
even when the array is zero-dimensional, thus fetching the word
after the allocated array space. While almost always harmless,
with very bad luck this could result in SIGSEGV. Fix by adding
an early exit for empty input.
Per bug #17920 from Alexander Lakhin.
Discussion: https://postgr.es/m/17920-f7c228c627b6d02e%40postgresql.org
Commit 6df7a9698b accidentally included two identical prototypes for
default_multirange_selectivi() and commit 086cf1458c added a break;
statement where one was already present, thus duplicating it. While
there is no bug caused by this, fix by removing the duplicated lines
as they provide no value.
Backpatch the fix for duplicate prototypes to v14 and the duplicate
break statement fix to all supported branches to avoid backpatching
hazards due to the removal.
Reported-by: Anton Voloshin <a.voloshin@postgrespro.ru>
Discussion: https://postgr.es/m/0e69cb60-0176-f6d0-7e15-6478b7d85724@postgrespro.ru
The nested-arrays code path in ExecEvalArrayExpr() used palloc to
allocate the result array, whereas every other array-creating function
has used palloc0 since 18c0b4ecc. This mostly works, but unused bits
past the end of the nulls bitmap may end up undefined. That causes
valgrind complaints with -DWRITE_READ_PARSE_PLAN_TREES, and could
cause planner misbehavior as cited in 18c0b4ecc. There seems no very
good reason why we should strive to avoid palloc0 in just this one case,
so fix it the easy way with s/palloc/palloc0/.
While looking at that I noted that we also failed to check for overflow
of "nbytes" and "nitems" while summing the sizes of the sub-arrays,
potentially allowing a crash due to undersized output allocation.
For "nbytes", follow the policy used by other array-munging code of
checking for overflow after each addition. (As elsewhere, the last
addition of the array's overhead space doesn't need an extra check,
since palloc itself will catch a value between 1Gb and 2Gb.)
For "nitems", there's no very good reason to sum the inputs at all,
since we can perfectly well use ArrayGetNItems' result instead of
ignoring it.
Per discussion of this bug, also remove redundant zeroing of the
nulls bitmap in array_set_element and array_set_slice.
Patch by Alexander Lakhin and myself, per bug #17858 from Alexander
Lakhin; thanks also to Richard Guo. These bugs are a dozen years old,
so back-patch to all supported branches.
Discussion: https://postgr.es/m/17858-8fd287fd3663d051@postgresql.org
gcc 12+ has complaints like the following:
../../../../../pgsql/src/backend/utils/adt/network.c: In function 'inetnot':
../../../../../pgsql/src/backend/utils/adt/network.c:1893:34: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=]
1893 | pdst[nb] = ~pip[nb];
| ~~~~~~~~~^~~~~~~~~~
../../../../../pgsql/src/include/utils/inet.h:27:23: note: at offset -1 into destination object 'ipaddr' of size 16
27 | unsigned char ipaddr[16]; /* up to 128 bits of address */
| ^~~~~~
../../../../../pgsql/src/include/utils/inet.h:27:23: note: at offset -1 into destination object 'ipaddr' of size 16
This is due to a compiler bug:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104986
It has been a year since the bug has been reported without getting fixed. As
the warnings are verbose and use of gcc 12 is becoming more common, it seems
worth working around the bug. Particularly because a simple reformulation of
the loop condition fixes the issue and isn't any less readable.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/144536.1648326206@sss.pgh.pa.us
Backpatch: 11-
The band-aid applied in commit f0bedf3e4 turns out to still need
some work: it made sure we didn't set Np->last_relevant too small
(to the left of the decimal point), but it didn't prevent setting
it too large (off the end of the partially-converted string).
This could result in fetching data beyond the end of the allocated
space, which with very bad luck could cause a SIGSEGV, though
I don't see any hazard of interesting memory disclosure.
Per bug #17839 from Thiago Nunes. The bug's pretty ancient,
so back-patch to all supported versions.
Discussion: https://postgr.es/m/17839-aada50db24d7b0da@postgresql.org
The majority of error exit cases in json_lex_string() failed to
set lex->token_terminator, causing problems for the error context
reporting code: it would see token_terminator less than token_start
and do something more or less nuts. In v14 and up the end result
could be as bad as a crash in report_json_context(). Older
versions accidentally avoided that fate; but all versions produce
error context lines that are far less useful than intended,
because they'd stop at the end of the prior token instead of
continuing to where the actually-bad input is.
To fix, invent some macros that make it less notationally painful
to do the right thing. Also add documentation about what the
function is actually required to do; and in >= v14, add an assertion
in report_json_context about token_terminator being sufficiently
far advanced.
Per report from Nikolay Shaplov. Back-patch to all supported
versions.
Discussion: https://postgr.es/m/7332649.x5DLKWyVIX@thinkpad-pgpro
This is usually harmless, but if you were very unlucky it could
provoke a segfault due to the "to" string being right up against
the end of memory. Found via valgrind testing (so we might've
found it earlier, except that our regression tests lacked any
exercise of translate()'s deletion feature).
Fix by switching the order of the test-for-end-of-string and
advance-pointer steps. While here, compute "to_ptr + tolen"
just once. (Smarter compilers might figure that out for
themselves, but let's just make sure.)
Report and fix by Daniil Anisimov, in bug #17816.
Discussion: https://postgr.es/m/17816-70f3d2764e88a108@postgresql.org
ruleutils.c blindly printed the user-given alias (or nothing if there
hadn't been one) for the target table of INSERT/UPDATE/DELETE queries.
That works a large percentage of the time, but not always: for queries
appearing in WITH, it's possible that we chose a different alias to
avoid conflict with outer-scope names. Since the chosen alias would
be used in any Var references to the target table, this'd lead to an
inconsistent printout with consequences such as dump/restore failures.
The correct logic for printing (or not) a relation alias was embedded
in get_from_clause_item. Factor it out to a separate function so that
we don't need a jointree node to use it. (Only a limited part of that
function can be reached from these new call sites, but this seems like
the cleanest non-duplicative factorization.)
In passing, I got rid of a redundant "\d+ rules_src" step in rules.sql.
Initial report from Jonathan Katz; thanks to Vignesh C for analysis.
This has been broken for a long time, so back-patch to all supported
branches.
Discussion: https://postgr.es/m/e947fa21-24b2-f922-375a-d4f763ef3e4b@postgresql.org
Discussion: https://postgr.es/m/CALDaNm1MMntjmT_NJGp-Z=xbF02qHGAyuSHfYHias3TqQbPF2w@mail.gmail.com
The prior coding of int64_div_fast_to_numeric() had a number of bugs
that would cause it to fail under different circumstances, such as
with log10val2 <= 0, or log10val2 a multiple of 4, or in the "slow"
numeric path with log10val2 >= 10.
None of those could be triggered by any of our current code, which
only uses log10val2 = 3 or 6. However, they made it a hazard for any
future code that might use it. Also, since this is exported by
numeric.c, users writing their own C code might choose to use it.
Therefore fix, and back-patch to v14, where it was introduced.
Dean Rasheed, reviewed by Tom Lane.
Discussion: https://postgr.es/m/CAEZATCW8gXgW0tgPxPgHDPhVX71%2BSWFRkhnXy%2BTfGDsKLepu2g%40mail.gmail.com
The current jsonpath code assumes that the referenced variable always exists.
It could only throw an error at the value valuation time. At the same time
existence checking assumes variable is present without valuation, and error
suppression doesn't work for missing variables.
This commit makes existense checking trigger an error for missing variables.
This makes the overall behavior consistent.
Backpatch to 12 where jsonpath was introduced.
Reported-by: David G. Johnston
Discussion: https://postgr.es/m/CAKFQuwbeytffJkVnEqDyLZ%3DrQsznoTh1OgDoOF3VmOMkxcTMjA%40mail.gmail.com
Author: Alexander Korotkov, David G. Johnston
Backpatch-through: 12
While on it, newlines are removed from the end of two elog() strings.
The others are simple grammar mistakes. One comment in pg_upgrade
referred incorrectly to sequences since a7e5457.
Author: Justin Pryzby
Discussion: https://postgr.es/m/20221230231257.GI1153@telsasoft.com
Backpatch-through: 11
jsonb_get_element() was incautious enough to use VARDATA() and
VARSIZE() directly on an arbitrary text Datum. That of course
fails if the Datum is short-header, compressed, or out-of-line.
The typical result would be failing to match any element of a
jsonb object, though matching the wrong one seems possible as well.
setPathObject() was slightly brighter, in that it used VARDATA_ANY
and VARSIZE_ANY_EXHDR, but that only kept it out of trouble for
short-header Datums. push_path() had the same issue. This could
result in faulty subscripted insertions, though keys long enough to
cause a problem are likely rare in the wild.
Having seen these, I looked around for unsafe usages in the rest
of the adt/json* files. There are a couple of places where it's not
immediately obvious that the Datum can't be compressed or out-of-line,
so I added pg_detoast_datum_packed() to cope if it is. Also, remove
some other usages of VARDATA/VARSIZE on Datums we just extracted from
a text array. Those aren't actively broken, but they will become so
if we ever start allowing short-header array elements, which does not
seem like a terribly unreasonable thing to do. In any case they are
not great coding examples, and they could also do with comments
pointing out that we're assuming we don't need pg_detoast_datum_packed.
Per report from exe-dealer@yandex.ru. Patch by me, but thanks to
David Johnston for initial investigation. Back-patch to v14 where
jsonb subscripting was introduced.
Discussion: https://postgr.es/m/205321670615953@mail.yandex.ru
Some options of these commands need to be able to identify the start
of the function body within the output of pg_get_functiondef().
It used to be that that always began with "AS", but since the
introduction of new-style SQL functions, it might also start with
"BEGIN" or "RETURN". Fix that on the psql side, and add some
regression tests.
Noted by me awhile ago, but I didn't do anything about it.
Thanks to David Johnston for a nag.
Discussion: https://postgr.es/m/AM9PR01MB8268D5CDABDF044EE9F42173FE8C9@AM9PR01MB8268.eurprd01.prod.exchangelabs.com
In commit 40c24bfef, I forgot to use get_rule_expr_paren() for the
arguments of AT TIME ZONE, resulting in possibly not printing parens
for expressions that need it. But get_rule_expr_paren() wouldn't have
gotten it right anyway, because isSimpleNode() hadn't been taught that
COERCE_SQL_SYNTAX parent nodes don't guarantee sufficient parentheses.
Improve all that. Also use this methodology for F_IS_NORMALIZED, so
that we don't print useless parens for that.
In passing, remove a comment that was obsoleted later.
Per report from Duncan Sands. Back-patch to v14 where this code
came in. (Before that, we didn't try to print AT TIME ZONE that way,
so there was no bug just ugliness.)
Discussion: https://postgr.es/m/f41566aa-a057-6628-4b7c-b48770ecb84a@deepbluecap.com
We've made multiple attempts at preventing get_actual_variable_range
from taking an unreasonable amount of time (3ca930fc3, fccebe421).
But there's still an issue for the very first planning attempt after
deletion of a large number of extremal-valued tuples. While that
planning attempt will set "killed" bits on the tuples it visits and
thereby reduce effort for next time, there's still a lot of work it
has to do to visit the heap and then set those bits. It's (usually?)
not worth it to do that much work at plan time to have a slightly
better estimate, especially in a context like this where the table
contents are known to be mutating rapidly.
Therefore, let's bound the amount of work to be done by giving up
after we've visited 100 heap pages. Giving up just means we'll
fall back on the extremal value recorded in pg_statistic, so it
shouldn't mean that planner estimates suddenly become worthless.
Note that this means we'll still gradually whittle down the problem
by setting a few more index "killed" bits in each planning attempt;
so eventually we'll reach a good state (barring further deletions),
even in the absence of VACUUM.
Simon Riggs, per a complaint from Jakub Wartak (with cosmetic
adjustments by me). Back-patch to all supported branches.
Discussion: https://postgr.es/m/CAKZiRmznOwi0oaV=4PHOCM4ygcH4MgSvt8=5cu_vNCfc8FSUug@mail.gmail.com
I just spent an annoying amount of time reverse-engineering the
100%-undocumented API between ts_headline and the text search
parser's prsheadline function. Add some commentary about that
while it's fresh in mind. Also remove some unused macros in
wparser_def.c.
While at it, I noticed that when commit 78e73e875 added a
CHECK_FOR_INTERRUPTS call in TS_execute_recurse, it missed
doing so in the parallel function TS_phrase_execute, which
surely needs one just as much.
Back-patch because of the missing CHECK_FOR_INTERRUPTS.
Might as well back-patch the rest of this too.
If the non-recursive term of a SEARCH BREADTH FIRST recursive
query has only constants in its target list, the planner will
fold the starting RowExpr added by rewrite into a simple Const
of type RECORD. The executor doesn't have any problem with
that --- but EXPLAIN VERBOSE will encounter the Const as the
ultimate source of truth about what the field names of the
SET column are, and it didn't know what to do with that.
Fortunately, we can pull the identifying typmod out of the
Const, in much the same way that record_out would.
For reasons that remain a bit obscure to me, this only fails
with SEARCH BREADTH FIRST, not SEARCH DEPTH FIRST or CYCLE.
But I added regression test cases for both of those options
too, just to make sure we don't break it in future.
Per bug #17644 from Matthijs van der Vleuten. Back-patch
to v14 where these constructs were added.
Discussion: https://postgr.es/m/17644-3bd1f3036d6d7a16@postgresql.org
This prevents marking the argument string for translation for gettext,
and it also prevents the given string (which is already translated) from
being translated at runtime.
Also, mark the strings used as arguments to check_rolespec_name for
translation.
Backpatch all the way back as appropriate. None of this is caught by
any tests (necessarily so), so I verified it manually.
clang 15+ will issue a set-but-not-used warning when the only
use of a variable is in autoincrements (e.g., "foo++;").
That's perfectly sensible, but it detects a few more cases that
we'd not noticed before. Silence the warnings with our usual
methods, such as PG_USED_FOR_ASSERTS_ONLY, or in one case by
actually removing a useless variable.
One thing that we can't nicely get rid of is that with %pure-parser,
Bison emits "yynerrs" as a local variable that falls foul of this
warning. To silence those, I inserted "(void) yynerrs;" in the
top-level productions of affected grammars.
Per recently-established project policy, this is a candidate
for back-patching into out-of-support branches: it suppresses
annoying compiler warnings but changes no behavior. Hence,
back-patch to 9.5, which is as far as these patches go without
issues. (A preliminary check shows that the prior branches
need some other set-but-not-used cleanups too, so I'll leave
them for another day.)
Discussion: https://postgr.es/m/514615.1663615243@sss.pgh.pa.us
Commit c4c340088 changed geometric operators to use float4 and float8
functions, and handle NaN's in a better way. The circle sameness test
had a typo in the code which resulted in all comparisons with the left
circle having a NaN radius considered same.
postgres=# select '<(0,0),NaN>'::circle ~= '<(0,0),1>'::circle;
?column?
----------
t
(1 row)
This fixes the sameness test to consider the radius of both the left
and right circle.
Backpatch to v12 where this was introduced.
Author: Ranier Vilela <ranier.vf@gmail.com>
Discussion: https://postgr.es/m/CAEudQAo8dK=yctg2ZzjJuzV4zgOPBxRU5+Kb+yatFiddtQk6Rw@mail.gmail.com
Backpatch-through: v12
SplitToVariants() in the ispell code, lseg_inside_poly() in geo_ops.c,
and regex_selectivity_sub() in selectivity estimation could recurse
until stack overflow; fix by adding check_stack_depth() calls.
So could next() in the regex compiler, but that case is better fixed by
converting its tail recursion to a loop. (We probably get better code
that way too, since next() can now be inlined into its sole caller.)
There remains a reachable stack overrun in the Turkish stemmer, but
we'll need some advice from the Snowball people about how to fix that.
Per report from Egor Chindyaskin and Alexander Lakhin. These mistakes
are old, so back-patch to all supported branches.
Richard Guo and Tom Lane
Discussion: https://postgr.es/m/1661334672.728714027@f473.i.mail.ru
When enlarging the work buffers of a VarStringSortSupport object,
varstrfastcmp_locale was careful to keep them in the ssup_cxt
memory context; but varstr_abbrev_convert just used palloc().
The latter creates a hazard that the buffers could be freed out
from under the VarStringSortSupport object, resulting in stomping
on whatever gets allocated in that memory later.
In practice, because we only use this code for ICU collations
(cf. 3df9c374e), the problem is confined to use of ICU collations.
I believe it may have been unreachable before the introduction
of incremental sort, too, as traditional sorting usually just
uses one context for the duration of the sort.
We could fix this by making the broken stanzas in varstr_abbrev_convert
match the non-broken ones in varstrfastcmp_locale. However, it seems
like a better idea to dodge the issue altogether by replacing the
pfree-and-allocate-anew coding with repalloc, which automatically
preserves the chunk's memory context. This fix does add a few cycles
because repalloc will copy the chunk's content, which the existing
coding assumes is useless. However, we don't expect that these buffer
enlargement operations are performance-critical. Besides that, it's
far from obvious that copying the buffer contents isn't required, since
these stanzas make no effort to mark the buffers invalid by resetting
last_returned, cache_blob, etc. That seems to be safe upon examination,
but it's fragile and could easily get broken in future, which wouldn't
get revealed in testing with short-to-moderate-size strings.
Per bug #17584 from James Inform. Whether or not the issue is
reachable in the older branches, this code has been broken on its
own terms from its introduction, so patch all the way back.
Discussion: https://postgr.es/m/17584-95c79b4a7d771f44@postgresql.org
The code tried to access ARR_DIMS(v)[0] and ARR_LBOUND(v)[0]
whether or not those values exist. This made the range check
on the "n" argument unstable --- it might or might not fail, and
if it did it would report garbage for the allowed upper limit.
These bogus accesses would probably annoy Valgrind, and if you
were very unlucky even lead to SIGSEGV.
Report and fix by Martin Kalcher. Back-patch to v14 where this
function was added.
Discussion: https://postgr.es/m/baaeb413-b8a8-4656-5757-ef347e5ec11f@aboutsource.net
This is a backpatch to branches 10-14 of the following commits:
7170f2159f Allow "in place" tablespaces.
c6f2f01611 Fix pg_basebackup with in-place tablespaces.
f6f0db4d62 Fix pg_tablespace_location() with in-place tablespaces
7a7cd84893 doc: Remove mention to in-place tablespaces for pg_tablespace_location()
5344723755 Remove unnecessary Windows-specific basebackup code.
In-place tablespaces were introduced as a testing helper mechanism, but
they are going to be used for a bugfix in WAL replay to be backpatched
to all stable branches.
I (Álvaro) had to adjust some code to account for lack of
get_dirent_type() in branches prior to 14.
Author: Thomas Munro <thomas.munro@gmail.com>
Author: Michaël Paquier <michael@paquier.xyz>
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/20220722081858.omhn2in5zt3g4nek@alvherre.pgsql
Due to lack of concern for the case in the dependency code, it's
possible to drop a column of a composite type even though stored
queries have references to the dropped column via functions-in-FROM
that return the composite type. There are "soft" references,
namely FROM-clause aliases for such columns, and "hard" references,
that is actual Vars referring to them. The right fix for hard
references is to add dependencies preventing the drop; something
we've known for many years and not done (and this commit still doesn't
address it). A "soft" reference shouldn't prevent a drop though.
We've been around on this before (cf. 9b35ddce9, 2c4debbd0), but
nobody had noticed that the current behavior can result in dump/reload
failures, because ruleutils.c can print more column aliases than the
underlying composite type now has. So we need to rejigger the
column-alias-handling code to treat such columns as dropped and not
print aliases for them.
Rather than writing new code for this, I used expandRTE() which already
knows how to figure out which function result columns are dropped.
I'd initially thought maybe we could use expandRTE() in all cases, but
that fails for EXPLAIN's purposes, because the planner strips a lot of
RTE infrastructure that expandRTE() needs. So this patch just uses it
for unplanned function RTEs and otherwise does things the old way.
If there is a hard reference (Var), then removing the column alias
causes us to fail to print the Var, since there's no longer a name
to print. Failing seems less desirable than printing a made-up
name, so I made it print "?dropped?column?" instead.
Per report from Timo Stolz. Back-patch to all supported branches.
Discussion: https://postgr.es/m/5c91267e-3b6d-5795-189c-d15a55d61dbb@nullachtvierzehn.de
The patch that added regcollation doesn't seem to have been too
thorough about supporting it everywhere that other reg* types
are supported. Fix that. (The find_expr_references omission
is moderately serious, since it could result in missing expression
dependencies. The others are less exciting.)
Noted while fixing bug #17483. Back-patch to v13 where
regcollation was added.
Discussion: https://postgr.es/m/1423433.1652722406@sss.pgh.pa.us
Justin Pryzby reported that some scenarios could cause gathering
of extended statistics to spend many seconds in an un-cancelable
qsort() operation. To fix, invent qsort_interruptible(), which is
just like qsort_arg() except that it will also do CHECK_FOR_INTERRUPTS
every so often. This bloats the backend by a couple of kB, which
seems like a good investment. (We considered just enabling
CHECK_FOR_INTERRUPTS in the existing qsort and qsort_arg functions,
but there are some callers for which that'd demonstrably be unsafe.
Opt-in seems like a better way.)
For now, just apply qsort_interruptible() in statistics collection.
There's probably more places where it could be useful, but we can
always change other call sites as we find problems.
Back-patch to v14. Before that we didn't have extended stats on
expressions, so that the problem was less severe. Also, this patch
depends on the sort_template infrastructure introduced in v14.
Tom Lane and Justin Pryzby
Discussion: https://postgr.es/m/20220509000108.GQ28830@telsasoft.com
None of the other bison parsers contains this directive, and it gives
rise to some unfortunate and impenetrable messages, so just remove it.
Backpatch to release 12, where it was introduced.
Per gripe from Erik Rijkers
Discussion: https://postgr.es/m/ba069ce2-a98f-dc70-dc17-2ccf2a9bf7c7@xs4all.nl
TransactionIdIsInProgress had a fast path to return 'false' if the
single-item CLOG cache said that the transaction was known to be
committed. However, that was wrong, because a transaction is first
marked as committed in the CLOG but doesn't become visible to others
until it has removed its XID from the proc array. That could lead to an
error:
ERROR: t_xmin is uncommitted in tuple to be updated
or for an UPDATE to go ahead without blocking, before the previous
UPDATE on the same row was made visible.
The window is usually very short, but synchronous replication makes it
much wider, because the wait for synchronous replica happens in that
window.
Another thing that makes it hard to hit is that it's hard to get such
a commit-in-progress transaction into the single item CLOG cache.
Normally, if you call TransactionIdIsInProgress on such a transaction,
it determines that the XID is in progress without checking the CLOG
and without populating the cache. One way to prime the cache is to
explicitly call pg_xact_status() on the XID. Another way is to use a
lot of subtransactions, so that the subxid cache in the proc array is
overflown, making TransactionIdIsInProgress rely on pg_subtrans and
CLOG checks.
This has been broken ever since it was introduced in 2008, but the race
condition is very hard to hit, especially without synchronous
replication. There were a couple of reports of the error starting from
summer 2021, but no one was able to find the root cause then.
TransactionIdIsKnownCompleted() is now unused. In 'master', remove it,
but I left it in place in backbranches in case it's used by extensions.
Also change pg_xact_status() to check TransactionIdIsInProgress().
Previously, it only checked the CLOG, and returned "committed" before
the transaction was actually made visible to other queries. Note that
this also means that you cannot use pg_xact_status() to reproduce the
bug anymore, even if the code wasn't fixed.
Report and analysis by Konstantin Knizhnik. Patch by Simon Riggs, with
the pg_xact_status() change added by me.
Author: Simon Riggs
Reviewed-by: Andres Freund
Discussion: https://www.postgresql.org/message-id/flat/4da7913d-398c-e2ad-d777-f752cf7f0bbb%40garret.ru
ruleutils.c was coded to suppress the AS label for a SELECT output
expression if the column name is "?column?", which is the parser's
fallback if it can't think of something better. This is fine, and
avoids ugly clutter, so long as (1) nothing further up in the parse
tree relies on that column name or (2) the same fallback would be
assigned when the rule or view definition is reloaded. Unfortunately
(2) is far from certain, both because ruleutils.c might print the
expression in a different form from how it was originally written
and because FigureColname's rules might change in future releases.
So we shouldn't rely on that.
Detecting exactly whether there is any outer-level use of a SELECT
column name would be rather expensive. This patch takes the simpler
approach of just passing down a flag indicating whether there *could*
be any outer use; for example, the output column names of a SubLink
are not referenceable, and we also do not care about the names exposed
by the right-hand side of a setop. This is sufficient to suppress
unwanted clutter in all but one case in the regression tests. That
seems like reasonable evidence that it won't be too much in users'
faces, while still fixing the cases we need to fix.
Per bug #17486 from Nicolas Lutic. This issue is ancient, so
back-patch to all supported branches.
Discussion: https://postgr.es/m/17486-1ad6fd786728b8af@postgresql.org
This reverts commit eafdf9de06
and its back-branch counterparts. Corey Huinker pointed out that
we'd discussed this exact change back in 2016 and rejected it,
on the grounds that there's at least one usage pattern with LIMIT
where an infinite endpoint can usefully be used. Perhaps that
argument needs to be re-litigated, but there's no time left before
our back-branch releases. To keep our options open, restore the
status quo ante; if we do end up deciding to change things, waiting
one more quarter won't hurt anything.
Rather than just doing a straight revert, I added a new test case
demonstrating the usage with LIMIT. That'll at least remind us of
the issue if we forget again.
Discussion: https://postgr.es/m/3603504.1652068977@sss.pgh.pa.us
Discussion: https://postgr.es/m/CADkLM=dzw0Pvdqp5yWKxMd+VmNkAMhG=4ku7GnCZxebWnzmz3Q@mail.gmail.com
Such cases will lead to infinite loops, so they're of no practical
value. The numeric variant of generate_series() already threw error
for this, so borrow its message wording.
Per report from Richard Wesley. Back-patch to all supported branches.
Discussion: https://postgr.es/m/91B44E7B-68D5-448F-95C8-B4B3B0F5DEAF@duckdblabs.com
The new numeric code for extract epoch from interval accidentally
truncated the DAYS_PER_YEAR value to an integer, leading to results
that mismatched the floating-point interval_part calculations.
The commit a2da77cdb4 that introduced
this actually contains the regression test change that this reverts.
I suppose this was missed at the time.
Reported-by: Joseph Koshakow <koshy44@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/CAAvxfHd5n%3D13NYA2q_tUq%3D3%3DSuWU-CufmTf-Ozj%3DfrEgt7pXwQ%40mail.gmail.com
pg_stat_get_replication_slot() accidentally was marked as non-strict, crashing
when called with NULL input. As it's already released, introduce an explicit
NULL check in 14, fix the catalog in HEAD.
Bumps catversion in HEAD.
Discussion: https://postgr.es/m/20220326212432.s5n2maw6kugnpyxw@alap3.anarazel.de
Backpatch: 14-, where replication slot stats were introduced
The planner needs to treat GroupingFunc like Aggref for many purposes,
in particular with respect to processing of the argument expressions,
which are not to be evaluated at runtime. A few places hadn't gotten
that memo, notably including subselect.c's processing of outer-level
aggregates. This resulted in assertion failures or wrong plans for
cases in which a GROUPING() construct references an outer aggregation
level.
Also fix missing special cases for GroupingFunc in cost_qual_eval
(resulting in wrong cost estimates for GROUPING(), although it's
not clear that that would affect plan shapes in practice) and in
ruleutils.c (resulting in excess parentheses in pretty-print mode).
Per bug #17088 from Yaoguang Chen. Back-patch to all supported
branches.
Richard Guo, Tom Lane
Discussion: https://postgr.es/m/17088-e33882b387de7f5c@postgresql.org
The output of table_to_xmlschema() and allied functions includes
a regex describing valid values for these types ... but the regex
was itself invalid, as it failed to escape a literal "+" sign.
Report and fix by Renan Soares Lopes. Back-patch to all
supported branches.
Discussion: https://postgr.es/m/7f6fabaa-3f8f-49ab-89ca-59fbfe633105@me.com
Most of these are cases where we could call memcpy() or other libc
functions with a NULL pointer and a zero count, which is forbidden
by POSIX even though every production version of libc allows it.
We've fixed such things before in a piecemeal way, but apparently
never made an effort to try to get them all. I don't claim that
this patch does so either, but it gets every failure I observe in
check-world, using clang 12.0.1 on current RHEL8.
numeric.c has a different issue that the sanitizer doesn't like:
"ln(-1.0)" will compute log10(0) and then try to assign the
resulting -Inf to an integer variable. We don't actually use the
result in such a case, so there's no live bug.
Back-patch to all supported branches, with the idea that we might
start running a buildfarm member that tests this case. This includes
back-patching c1132aae3 (Check the size in COPY_POINTER_FIELD),
which previously silenced some of these issues in copyfuncs.c.
Discussion: https://postgr.es/m/CALNJ-vT9r0DSsAOw9OXVJFxLENoVS_68kJ5x0p44atoYH+H4dg@mail.gmail.com
Commit 8431e296ea reworked ProcArrayApplyRecoveryInfo to sort XIDs
before adding them to KnownAssignedXids. But the XIDs are sorted using
xidComparator, which compares the XIDs simply as uint32 values, not
logically. KnownAssignedXidsAdd() however expects XIDs in logical order,
and calls TransactionIdFollowsOrEquals() to enforce that. If there are
XIDs for which the two orderings disagree, an error is raised and the
recovery fails/restarts.
Hitting this issue is fairly easy - you just need two transactions, one
started before the 4B limit (e.g. XID 4294967290), the other sometime
after it (e.g. XID 1000). Logically (4294967290 <= 1000) but when
compared using xidComparator we try to add them in the opposite order.
Which makes KnownAssignedXidsAdd() fail with an error like this:
ERROR: out-of-order XID insertion in KnownAssignedXids
This only happens during replica startup, while processing RUNNING_XACTS
records to build the snapshot. Once we reach STANDBY_SNAPSHOT_READY, we
skip these records. So this does not affect already running replicas,
but if you restart (or create) a replica while there are transactions
with XIDs for which the two orderings disagree, you may hit this.
Long-running transactions and frequent replica restarts increase the
likelihood of hitting this issue. Once the replica gets into this state,
it can't be started (even if the old transactions are terminated).
Fixed by sorting the XIDs logically - this is fine because we're dealing
with normal XIDs (because it's XIDs assigned to backends) and from the
same wraparound epoch (otherwise the backends could not be running at
the same time on the primary node). So there are no problems with the
triangle inequality, which is why xidComparator compares raw values.
Investigation and root cause analysis by Abhijit Menon-Sen. Patch by me.
This issue is present in all releases since 9.4, however releases up to
9.6 are EOL already so backpatch to 10 only.
Reviewed-by: Abhijit Menon-Sen
Reviewed-by: Alvaro Herrera
Backpatch-through: 10
Discussion: https://postgr.es/m/36b8a501-5d73-277c-4972-f58a4dce088a%40enterprisedb.com
Tom Lane
Bruce Momjian
Noah Misch
Michael Paquier
David Rowley
Daniel Gustafsson
Andres Freund
Dean Rasheed
Alexander Korotkov
Jeff Davis
Alvaro Herrera
Andrew Dunstan
Heikki Linnakangas
Peter Eisentraut
Tomas Vondra