Commit Graph

30 Commits

Author SHA1 Message Date
Tom Lane
c168ba3112 Free libxml2/libxslt resources in a safer order.
Mark Simonetti reported that libxslt sometimes crashes for him, and that
swapping xslt_process's object-freeing calls around to do them in reverse
order of creation seemed to fix it.  I've not reproduced the crash, but
valgrind clearly shows a reference to already-freed memory, which is
consistent with the idea that shutdown of the xsltTransformContext is
trying to reference the already-freed stylesheet or input document.
With this patch, valgrind is no longer unhappy.

I have an inquiry in to see if this is a libxslt bug or if we're just
abusing the library; but even if it's a library bug, we'd want to adjust
our code so it doesn't fail with unpatched libraries.

Back-patch to all supported branches, because we've been doing this in
the wrong(?) order for a long time.
2014-11-27 11:13:29 -05:00
Peter Eisentraut
e7128e8dbb Create function prototype as part of PG_FUNCTION_INFO_V1 macro
Because of gcc -Wmissing-prototypes, all functions in dynamically
loadable modules must have a separate prototype declaration.  This is
meant to detect global functions that are not declared in header files,
but in cases where the function is called via dfmgr, this is redundant.
Besides filling up space with boilerplate, this is a frequent source of
compiler warnings in extension modules.

We can fix that by creating the function prototype as part of the
PG_FUNCTION_INFO_V1 macro, which such modules have to use anyway.  That
makes the code of modules cleaner, because there is one less place where
the entry points have to be listed, and creates an additional check that
functions have the right prototype.

Remove now redundant prototypes from contrib and other modules.
2014-04-18 00:03:19 -04:00
Tom Lane
adc97d03b9 Prevent access to external files/URLs via contrib/xml2's xslt_process().
libxslt offers the ability to read and write both files and URLs through
stylesheet commands, thus allowing unprivileged database users to both read
and write data with the privileges of the database server.  Disable that
through proper use of libxslt's security options.

Also, remove xslt_process()'s ability to fetch documents and stylesheets
from external files/URLs.  While this was a documented "feature", it was
long regarded as a terrible idea.  The fix for CVE-2012-3489 broke that
capability, and rather than expend effort on trying to fix it, we're just
going to summarily remove it.

While the ability to write as well as read makes this security hole
considerably worse than CVE-2012-3489, the problem is mitigated by the fact
that xslt_process() is not available unless contrib/xml2 is installed,
and the longstanding warnings about security risks from that should have
discouraged prudent DBAs from installing it in security-exposed databases.

Reported and fixed by Peter Eisentraut.

Security: CVE-2012-3488
2012-08-14 18:31:18 -04:00
Bruce Momjian
927d61eeff Run pgindent on 9.2 source tree in preparation for first 9.3
commit-fest.
2012-06-10 15:20:04 -04:00
Tom Lane
d9b31e4859 Fix some more bugs in contrib/xml2's xslt_process().
It failed to check for error return from xsltApplyStylesheet(), as reported
by Peter Gagarinov.  (So far as I can tell, libxslt provides no convenient
way to get a useful error message in failure cases.  There might be some
inconvenient way, but considering that this code is deprecated it's hard to
get enthusiastic about putting lots of work into it.  So I just made it say
"failed to apply stylesheet", in line with the existing error checks.)

While looking at the code I also noticed that the string returned by
xsltSaveResultToString was never freed, resulting in a session-lifespan
memory leak.

Back-patch to all supported versions.
2012-06-04 20:12:50 -04:00
Tom Lane
cacd42d62c Rewrite libxml error handling to be more robust.
libxml reports some errors (like invalid xmlns attributes) via the error
handler hook, but still returns a success indicator to the library caller.
This causes us to miss some errors that are important to report.  Since the
"generic" error handler hook doesn't know whether the message it's getting
is for an error, warning, or notice, stop using that and instead start
using the "structured" error handler hook, which gets enough information
to be useful.

While at it, arrange to save and restore the error handler hook setting in
each libxml-using function, rather than assuming we can set and forget the
hook.  This should improve the odds of working nicely with third-party
libraries that also use libxml.

In passing, volatile-ize some local variables that get modified within
PG_TRY blocks.  I noticed this while testing with an older gcc version
than I'd previously tried to compile xml.c with.

Florian Pflug and Tom Lane, with extensive review/testing by Noah Misch
2011-07-20 13:03:49 -04:00
Bruce Momjian
bf50caf105 pgindent run before PG 9.1 beta 1. 2011-04-10 11:42:00 -04:00
Magnus Hagander
9f2e211386 Remove cvs keywords from all files. 2010-09-20 22:08:53 +02:00
Tom Lane
c04fd1b9db Remove the arbitrary (and undocumented) limit on the number of parameter=value
pairs that can be handled by xslt_process().

There is much else to do here, but this patch seems useful in its own right
for as long as this code survives.

Pavel Stehule, reviewed by Mike Fowler
2010-08-10 23:02:00 +00:00
Bruce Momjian
239d769e7e pgindent run for 9.0, second run 2010-07-06 19:19:02 +00:00
Tom Lane
5e47403be3 Make contrib/xml2 use core xml.c's error handler, when available (that is,
in versions >= 8.3).  The core code is more robust and efficient than what
was there before, and this also reduces risks involved in swapping different
libxml error handler settings.

Before 8.3, there is still some risk of problems if add-on modules such as
Perl invoke libxml without setting their own error handler.  Given the lack
of reports I'm not sure there's a risk in practice, so I didn't take the
step of actually duplicating the core code into older contrib/xml2 branches.
Instead I just tweaked the existing code to ensure it didn't leave a dangling
pointer to short-lived memory when throwing an error.
2010-03-03 19:10:22 +00:00
Tom Lane
d6a6f8c6be Fix contrib/xml2 so regression test still works when it's built without libxslt.
This involves modifying the module to have a stable ABI, that is, the
xslt_process() function still exists even without libxslt.  It throws a
runtime error if called, but doesn't prevent executing the CREATE FUNCTION
call.  This is a good thing anyway to simplify cross-version upgrades.
2010-03-01 18:07:59 +00:00
Tom Lane
a102090995 Remove xmlCleanupParser calls from contrib/xml2.
These are unnecessary and probably dangerous.  I don't see any immediate
risk situations in the core XML support or contrib/xml2 itself, but there
could be issues with external uses of libxml2, and in any case it's an
accident waiting to happen.
2010-03-01 05:16:35 +00:00
Tom Lane
a12333eed2 Assorted code cleanup for contrib/xml2. No change in functionality,
just make it a bit less ugly in places.
2010-02-28 19:51:37 +00:00
Tom Lane
e7370babd1 Fix xslt_process() to ensure that it inserts a NULL terminator after the
last pair of parameter name/value strings, even when there are MAXPARAMS
of them.  Aboriginal bug in contrib/xml2, noted while studying bug #4912
(though I'm not sure whether there's something else involved in that
report).

This might be thought a security issue, since it's a potential backend
crash; but considering that untrustworthy users shouldn't be allowed
to get their hands on xslt_process() anyway, it's probably not worth
getting excited about.
2009-07-10 00:32:00 +00:00
Bruce Momjian
d747140279 8.4 pgindent run, with new combined Linux/FreeBSD/MinGW typedef list
provided by Andrew.
2009-06-11 14:49:15 +00:00
Tom Lane
1cfd9e8834 Fix executor/spi.h to follow our usual conventions for include files, ie,
not include postgres.h nor anything else it doesn't directly need.  Add
#includes to calling files as needed to compensate.  Per my proposal of
yesterday.

This should be noted as a source code change in the 8.4 release notes,
since it's likely to require changes in add-on modules.
2009-01-07 13:44:37 +00:00
Andrew Dunstan
53972b460c Add $PostgreSQL$ markers to a lot of files that were missing them.
This particular batch was just for *.c and *.h file.

The changes were made with the following 2 commands:

find . \( \( -name 'libstemmer' -o -name 'expected' -o -name 'ppport.h' \) -prune \) -o  \( -name '*.[ch]'  \) \( -exec grep -q '\$PostgreSQL' {} \; -o -print \) | while read file ; do head -n 1 < $file | grep -q '^/\*' && echo $file; done | xargs -l sed -i -e '1s/^\// /' -e '1i/*\n * $PostgreSQL:$ \n *'

find . \( \( -name 'libstemmer' -o -name 'expected' -o -name 'ppport.h' \) -prune \) -o  \( -name '*.[ch]'  \) \( -exec grep -q '\$PostgreSQL' {} \; -o -print \) | xargs -l sed -i -e '1i/*\n * $PostgreSQL:$ \n */'
2008-05-17 01:28:26 +00:00
Tom Lane
eb915caf92 Fix contrib/xml2 makefile to not override CFLAGS, and in passing make it
auto-configure properly for libxslt present or not.
2008-05-08 16:49:37 +00:00
Tom Lane
45173ae24e Use new cstring/text conversion functions in some additional places.
These changes assume that the varchar and xml data types are represented
the same as text.  (I did not, however, accept the portions of the proposed
patch that wanted to assume bytea is the same as text --- tgl.)

Brendan Jurd
2008-05-04 16:42:41 +00:00
Tom Lane
220db7ccd8 Simplify and standardize conversions between TEXT datums and ordinary C
strings.  This patch introduces four support functions cstring_to_text,
cstring_to_text_with_len, text_to_cstring, and text_to_cstring_buffer, and
two macros CStringGetTextDatum and TextDatumGetCString.  A number of
existing macros that provided variants on these themes were removed.

Most of the places that need to make such conversions now require just one
function or macro call, in place of the multiple notational layers that used
to be needed.  There are no longer any direct calls of textout or textin,
and we got most of the places that were using handmade conversions via
memcpy (there may be a few still lurking, though).

This commit doesn't make any serious effort to eliminate transient memory
leaks caused by detoasting toasted text objects before they reach
text_to_cstring.  We changed PG_GETARG_TEXT_P to PG_GETARG_TEXT_PP in a few
places where it was easy, but much more could be done.

Brendan Jurd and Tom Lane
2008-03-25 22:42:46 +00:00
Tom Lane
4608f359a6 Fix a passel of signed vs unsigned char warnings. 2007-07-15 23:30:19 +00:00
Tom Lane
234a02b2a8 Replace direct assignments to VARATT_SIZEP(x) with SET_VARSIZE(x, len).
Get rid of VARATT_SIZE and VARATT_DATA, which were simply redundant with
VARSIZE and VARDATA, and as a consequence almost no code was using the
longer names.  Rename the length fields of struct varlena and various
derived structures to catch anyplace that was accessing them directly;
and clean up various places so caught.  In itself this patch doesn't
change any behavior at all, but it is necessary infrastructure if we hope
to play any games with the representation of varlena headers.
Greg Stark and Tom Lane
2007-02-27 23:48:10 +00:00
Tom Lane
7ce2ff2d22 Move xml2's PG_MODULE_MAGIC block to the right source file, per Michael Fuhr. 2006-09-11 15:30:32 +00:00
Tom Lane
a0ffab351e Magic blocks don't do us any good unless we use 'em ... so install one
in every shared library.
2006-05-30 22:12:16 +00:00
Neil Conway
8e5a10d46c This patch makes the error message strings throughout the backend
more compliant with the error message style guide. In particular,
errdetail should begin with a capital letter and end with a period,
whereas errmsg should not. I also fixed a few related issues in
passing, such as fixing the repeated misspelling of "lexeme" in
contrib/tsearch2 (per Tom's suggestion).
2006-03-01 06:30:32 +00:00
Bruce Momjian
1dc3498251 Standard pgindent run for 8.1. 2005-10-15 02:49:52 +00:00
Bruce Momjian
a5d7ba773d Adjust comments previously moved to column 1 by pgident. 2004-10-07 15:21:58 +00:00
Bruce Momjian
b6b71b85bc Pgindent run for 8.0. 2004-08-29 05:07:03 +00:00
Bruce Momjian
31f4b59a46 Move new version of contrib/ xml into xml2, keep old version in /xml. 2004-03-05 03:57:58 +00:00