If libpq ran out of memory while constructing the result set, it would hang,
waiting for more data from the server, which might never arrive. To fix,
distinguish between out-of-memory error and not-enough-data cases, and give
a proper error message back to the client on OOM.
There are still similar issues in handling COPY start messages, but let's
handle that as a separate patch.
Michael Paquier, Amit Kapila and me. Backpatch to all supported versions.
The previous coding could overrun the provided buffer size for a very large
input, or lose precision for a very small input. Adopt the methodology
that's been in use in the equivalent backend code for a long time.
Per private report from Bas van Schaik. Back-patch to all supported
branches.
Previously, if no host information had been specified at connection time,
PQhost() would return NULL (unless you are on Windows, in which case you
got "localhost"). This is an unhelpful definition for a couple of reasons:
it can cause corner-case crashes in applications (cf commit c5ef8ce53d),
and there's no well-defined way for applications to find out the socket
directory path that's actually in use. As an example of the latter
problem, psql substituted DEFAULT_PGSOCKET_DIR for NULL in a couple of
places, but this is subtly wrong because it's conceivable that psql is
using a libpq shared library that was built with a different setting.
Hence, change PQhost() to return DEFAULT_PGSOCKET_DIR when appropriate,
and strip out the now-dead substitutions in psql. (There is still one
remaining reference to DEFAULT_PGSOCKET_DIR in psql, in prompt.c, which
I don't see a nice way to get rid of. But it only controls a prompt
abbreviation decision, so it seems noncritical.)
Also update the docs for PQhost, which had never previously mentioned
the possibility of a socket directory path being returned. In passing
fix the outright-incorrect code comment about PGconn.pgunixsocket.
In commit 210eb9b743 I centralized libpq's logic for closing down
the backend communication socket, and made the new pqDropConnection
routine always reset the I/O buffers to empty. Many of the call sites
previously had not had such code, and while that amounted to an oversight
in some cases, there was one place where it was intentional and necessary
*not* to flush the input buffer: pqReadData should never cause that to
happen, since we probably still want to process whatever data we read.
This is the true cause of the problem Robert was attempting to fix in
c3e7c24a1d, namely that libpq no longer reported the backend's final
ERROR message before reporting "server closed the connection unexpectedly".
But that only accidentally fixed it, by invoking parseInput before the
input buffer got flushed; and very likely there are timing scenarios
where we'd still lose the message before processing it.
To fix, pass a flag to pqDropConnection to tell it whether to flush the
input buffer or not. On review I think flushing is actually correct for
every other call site.
Back-patch to 9.3 where the problem was introduced. In HEAD, also improve
the comments added by c3e7c24a1d.
At least since the introduction of Hot Standby, the backend has
sometimes sent fatal errors even when no client query was in
progress, assuming that the client would receive it. However,
pqHandleSendFailure was not in sync with this assumption, and
only tries to catch notices and notifies. Add a parseInput call
to the loop there to fix.
Andres Freund suggested the fix. Comments are by me.
Reviewed by Michael Paquier.
Per discussion, the original name was a bit misleading, and
PQsslAttributeNames() seems more apropos. It's not quite too late to
change this in 9.5, so let's change it while we can.
Also, make sure that the pointer array is const, not only the pointed-to
strings.
Minor documentation wordsmithing while at it.
Lars Kanis, slight adjustments by me
Thom Brown reported that SSL connections didn't seem to work on Windows in
9.5. Asif Naeem figured out that the cause was my_sock_read() looking at
"errno" when it needs to look at "SOCK_ERRNO". This mistake was introduced
in commit 680513ab79, which cloned the
backend's custom SSL BIO code into libpq, and didn't translate the errno
handling properly. Moreover, it introduced unnecessary errno save/restore
logic, which was particularly confusing because it was incomplete; and it
failed to check for all three of EINTR, EAGAIN, and EWOULDBLOCK in
my_sock_write. (That might not be necessary; but since we're copying
well-tested backend code that does do that, it seems prudent to copy it
faithfully.)
Remove the code in plpgsql that suppressed the innermost line of CONTEXT
for messages emitted by RAISE commands. That was never more than a quick
backwards-compatibility hack, and it's pretty silly in cases where the
RAISE is nested in several levels of function. What's more, it violated
our design theory that verbosity of error reports should be controlled
on the client side not the server side.
To alleviate the resulting noise increase, introduce a feature in libpq
and psql whereby the CONTEXT field of messages can be suppressed, either
always or only for non-error messages. Printing CONTEXT for errors only
is now their default behavior.
The actual code changes here are pretty small, but the effects on the
regression test outputs are widespread. I had to edit some of the
alternative expected outputs by hand; hopefully the buildfarm will soon
find anything I fat-fingered.
In passing, fix up (again) the output line counts in psql's various
help displays. Add some commentary about how to verify them.
Pavel Stehule, reviewed by Petr Jelínek, Jeevan Chalke, and others
If an allocation fails in the main message handling loop, pqParseInput3
or pqParseInput2, it should not be treated as "not enough data available
yet". Otherwise libpq will wait indefinitely for more data to arrive from
the server, and gets stuck forever.
This isn't a complete fix - getParamDescriptions and getCopyStart still
have the same issue, but it's a step in the right direction.
Michael Paquier and me. Backpatch to all supported versions.
Use "a" and "an" correctly, mostly in comments. Two error messages were
also fixed (they were just elogs, so no translation work required). Two
function comments in pg_proc.h were also fixed. Etsuro Fujita reported one
of these, but I found a lot more with grep.
Also fix a few other typos spotted while grepping for the a/an typos.
For example, "consists out of ..." -> "consists of ...". Plus a "though"/
"through" mixup reported by Euler Taveira.
Many of these typos were in old code, which would be nice to backpatch to
make future backpatching easier. But much of the code was new, and I didn't
feel like crafting separate patches for each branch. So no backpatching.
This reverts commit 16304a0134, except
for its changes in src/port/snprintf.c; as well as commit
cac18a76bb which is no longer needed.
Fujii Masao reported that the previous commit caused failures in psql on
OS X, since if one exits the pager program early while viewing a query
result, psql sees an EPIPE error from fprintf --- and the wrapper function
thought that was reason to panic. (It's a bit surprising that the same
does not happen on Linux.) Further discussion among the security list
concluded that the risk of other such failures was far too great, and
that the one-size-fits-all approach to error handling embodied in the
previous patch is unlikely to be workable.
This leaves us again exposed to the possibility of the type of failure
envisioned in CVE-2015-3166. However, that failure mode is strictly
hypothetical at this point: there is no concrete reason to believe that
an attacker could trigger information disclosure through the supposed
mechanism. In the first place, the attack surface is fairly limited,
since so much of what the backend does with format strings goes through
stringinfo.c or psprintf(), and those already had adequate defenses.
In the second place, even granting that an unprivileged attacker could
control the occurrence of ENOMEM with some precision, it's a stretch to
believe that he could induce it just where the target buffer contains some
valuable information. So we concluded that the risk of non-hypothetical
problems induced by the patch greatly outweighs the security risks.
We will therefore revert, and instead undertake closer analysis to
identify specific calls that may need hardening, rather than attempt a
universal solution.
We have kept the portion of the previous patch that improved snprintf.c's
handling of errors when it calls the platform's sprintf(). That seems to
be an unalloyed improvement.
Security: CVE-2015-3166
All known standard library implementations of these functions can fail
with ENOMEM. A caller neglecting to check for failure would experience
missing output, information exposure, or a crash. Check return values
within wrappers and code, currently just snprintf.c, that bypasses the
wrappers. The wrappers do not return after an error, so their callers
need not check. Back-patch to 9.0 (all supported versions).
Popular free software standard library implementations do take pains to
bypass malloc() in simple cases, but they risk ENOMEM for floating point
numbers, positional arguments, large field widths, and large precisions.
No specification demands such caution, so this commit regards every call
to a printf family function as a potential threat.
Injecting the wrappers implicitly is a compromise between patch scope
and design goals. I would prefer to edit each call site to name a
wrapper explicitly. libpq and the ECPG libraries would, ideally, convey
errors to the caller rather than abort(). All that would be painfully
invasive for a back-patched security fix, hence this compromise.
Security: CVE-2015-3166
The "check" target no longer needs to depend on "all", because it now
runs "install" directly, which in turn depends on "all". Doing both
will cause problems with parallel make, because two builds will run next
to each other.
Also remove the redirection of the temp-install output into a log file.
This was appropriate when this was done from within pg_regress, but now
it's just a regular make run, and especially with the above changes this
will now take the place of running the "all" target before the test
suites.
problem report by Jeff Janes, patch in part by Michael Paquier
This provides a mechanism for specifying conversions between SQL data
types and procedural languages. As examples, there are transforms
for hstore and ltree for PL/Perl and PL/Python.
reviews by Pavel Stěhule and Andres Freund
Each of the libraries incorporates src/port files, which often check
FRONTEND. Build systems disagreed on whether to build libpgtypes this
way. Only libecpg incorporates files that rely on it today. Back-patch
to 9.0 (all supported versions) to forestall surprises.
Before, make check-world would create a new temporary installation for
each test suite, which is slow and wasteful. Instead, we now create one
test installation that is used by all test suites that are part of a
make run.
The management of the temporary installation is removed from pg_regress
and handled in the makefiles. This allows for better control, and
unifies the code with that of test suites not run through pg_regress.
review and msvc support by Michael Paquier <michael.paquier@gmail.com>
more review by Fabien Coelho <coelho@cri.ensmp.fr>
If someone else already set the callbacks, don't overwrite them with
ours. When unsetting the callbacks, only unset them if they point to
ours.
Author: Jan Urbański <wulczer@wulczer.org>
This is the second try at this, after fcef161729 failed miserably and
had to be reverted: as it turns out, libpq cannot depend on libpgcommon
after all. Instead of shuffling code in the master branch, make that one
just like 9.4 and accept the duplication. (This was all my own mistake,
not the patch submitter's).
psql was already accepting conninfo strings as the first parameter in
\connect, but the way it worked wasn't sane; some of the other
parameters would get the previous connection's values, causing it to
connect to a completely unexpected server or, more likely, not finding
any server at all because of completely wrong combinations of
parameters.
Fix by explicitely checking for a conninfo-looking parameter in the
dbname position; if one is found, use its complete specification rather
than mix with the other arguments. Also, change tab-completion to not
try to complete conninfo/URI-looking "dbnames" and document that
conninfos are accepted as first argument.
There was a weak consensus to backpatch this, because while the behavior
of using the dbname as a conninfo is nowhere documented for \connect, it
is reasonable to expect that it works because it does work in many other
contexts. Therefore this is backpatched all the way back to 9.0.
Author: David Fetter, Andrew Dunstan. Some editorialization by me
(probably earning a Gierth's "Sloppy" badge in the process.)
Reviewers: Andrew Gierth, Erik Rijkers, Pavel Stěhule, Stephen Frost,
Robert Haas, Andrew Dunstan.
psql was already accepting conninfo strings as the first parameter in
\connect, but the way it worked wasn't sane; some of the other
parameters would get the previous connection's values, causing it to
connect to a completely unexpected server or, more likely, not finding
any server at all because of completely wrong combinations of
parameters.
Fix by explicitely checking for a conninfo-looking parameter in the
dbname position; if one is found, use its complete specification rather
than mix with the other arguments. Also, change tab-completion to not
try to complete conninfo/URI-looking "dbnames" and document that
conninfos are accepted as first argument.
There was a weak consensus to backpatch this, because while the behavior
of using the dbname as a conninfo is nowhere documented for \connect, it
is reasonable to expect that it works because it does work in many other
contexts. Therefore this is backpatched all the way back to 9.0.
To implement this, routines previously private to libpq have been
duplicated so that psql can decide what looks like a conninfo/URI
string. In back branches, just duplicate the same code all the way back
to 9.2, where URIs where introduced; 9.0 and 9.1 have a simpler version.
In master, the routines are moved to src/common and renamed.
Author: David Fetter, Andrew Dunstan. Some editorialization by me
(probably earning a Gierth's "Sloppy" badge in the process.)
Reviewers: Andrew Gierth, Erik Rijkers, Pavel Stěhule, Stephen Frost,
Robert Haas, Andrew Dunstan.
This improves on commit bbfd7edae5 by
making two simple changes:
* pg_attribute_noreturn now takes parentheses, ie pg_attribute_noreturn().
Likewise pg_attribute_unused(), pg_attribute_packed(). This reduces
pgindent's tendency to misformat declarations involving them.
* attributes are now always attached to function declarations, not
definitions. Previously some places were taking creative shortcuts,
which were not merely candidates for bad misformatting by pgindent
but often were outright wrong anyway. (It does little good to put a
noreturn annotation where callers can't see it.) In any case, if
we would like to believe that these macros can be used with non-gcc
compilers, we should avoid gratuitous variance in usage patterns.
I also went through and manually improved the formatting of a lot of
declarations, and got rid of excessively repetitive (and now obsolete
anyway) comments informing the reader what pg_attribute_printf is for.
Peter Eisentraut
Robert Haas
Andrew Dunstan
Michael Meskes
Bruce Momjian
Heikki Linnakangas
Tom Lane
Greg Stark
Noah Misch
Andres Freund
Alvaro Herrera