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
xml_parse() would attempt to fetch external files or URLs as needed to resolve DTD and entity references in an XML value, thus allowing unprivileged database users to attempt to fetch data with the privileges of the database server. While the external data wouldn't get returned directly to the user, portions of it could be exposed in error messages if the data didn't parse as valid XML; and in any case the mere ability to check existence of a file might be useful to an attacker. The ideal solution to this would still allow fetching of references that are listed in the host system's XML catalogs, so that documents can be validated according to installed DTDs. However, doing that with the available libxml2 APIs appears complex and error-prone, so we're not going to risk it in a security patch that necessarily hasn't gotten wide review. So this patch merely shuts off all access, causing any external fetch to silently expand to an empty string. A future patch may improve this. In HEAD and 9.2, also suppress warnings about undefined entities, which would otherwise occur as a result of not loading referenced DTDs. Previous branches don't show such warnings anyway, due to different error handling arrangements. Credit to Noah Misch for first reporting the problem, and for much work towards a solution, though this simplistic approach was not his preference. Also thanks to Daniel Veillard for consultation. Security: CVE-2012-3489
DST law changes in Morocco; Tokelau has relocated to the other side of the International Date Line; and apparently Olson had Tokelau's GMT offset wrong by an hour even before that. There are also a large number of non-significant changes in this update. Upstream took the opportunity to remove trailing whitespace, and the SCCS-style version numbers on the individual files are gone too.
Dave Kerr, backpatched by Simon Riggs
In the original coding of the log rotation stuff, we did not bother to make the truncation logic work for the very first rotation after postmaster start (or after a syslogger crash and restart). It just always appended in that case. It did not seem terribly important at the time, but we've recently had two separate complaints from people who expected it to work unsurprisingly. (Both users tend to restart the postmaster about as often as a log rotation is configured to happen, which is maybe not typical use, but still...) Since the initial log file is opened in the postmaster, fixing this requires passing down some more state to the syslogger child process. It's always been like this, so back-patch to all supported branches.
This function suppressed any stderr output from the called program, which is unnecessary in the normal case and unhelpful in error cases. It also gave a rather opaque message along the lines of "fgets failure: Success" in case the called program failed to return anything on stdout. Since we've seen multiple reports of people not understanding what's wrong when pg_ctl reports this, improve the message. Back-patch to all active branches.
In the original coding of the autovacuum cancel feature, commit acac68b2bcae818bc8803b8cb8cbb17eee8d5e2b, an autovacuum process was considered a target for cancellation if it was found to hard-block any process examined in the deadlock search. This patch tightens the test so that the autovacuum must directly hard-block the current process. This should make the behavior more predictable in general, and in particular it ensures that an autovacuum will not be canceled with less than deadlock_timeout grace period. In the old coding, it was possible for an autovacuum to be canceled almost instantly, given unfortunate timing of two or more other processes' lock attempts. This also justifies the logging methodology in the recent commit d7318d43d891bd63e82dcfc27948113ed7b1db80; without this restriction, that patch isn't providing enough information to see the connection of the canceling process to the autovacuum. Like that one, patch all the way back.