commit 74b1ed684e30ef68e0eee52550720b8771e5f0a0 Author: Nick Mathewson nickm@torproject.org Date: Sat Mar 3 07:57:18 2018 -0500

copy changelog into release notes --- ReleaseNotes | 177 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 177 insertions(+)

diff --git a/ReleaseNotes b/ReleaseNotes index e691e092b..c874583c9 100644 --- a/ReleaseNotes +++ b/ReleaseNotes @@ -2,6 +2,183 @@ This document summarizes new features and bugfixes in each stable release of Tor. If you want to see more detailed descriptions of the changes in each development snapshot, see the ChangeLog file.

+Changes in version 0.2.9.15 - 2018-03-03 + Tor 0.2.9.15 backports important security and stability bugfixes from + later Tor releases. + + It includes an important security fix for a remote crash attack + against directory authorities, tracked as TROVE-2018-001. + + This release also backports our new system for improved resistance to + denial-of-service attacks against relays. + + This release also fixes several minor bugs and annoyances from + earlier releases. + + All directory authorities should upgrade to one of the versions + released today. Relays running 0.2.9.x may wish to update to one of + the versions released today, for the DoS mitigations. + + o Major bugfixes (denial-of-service, directory authority, backport from 0.3.3.3-alpha): + - Fix a protocol-list handling bug that could be used to remotely crash + directory authorities with a null-pointer exception. Fixes bug 25074; + bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2018-001 and + CVE-2018-0490. + + o Major features (denial-of-service mitigation): + - Give relays some defenses against the recent network overload. We + start with three defenses (default parameters in parentheses). + First: if a single client address makes too many concurrent + connections (>100), hang up on further connections. Second: if a + single client address makes circuits too quickly (more than 3 per + second, with an allowed burst of 90) while also having too many + connections open (3), refuse new create cells for the next while + (1-2 hours). Third: if a client asks to establish a rendezvous + point to you directly, ignore the request. These defenses can be + manually controlled by new torrc options, but relays will also + take guidance from consensus parameters, so there's no need to + configure anything manually. Implements ticket 24902. + + o Major bugfixes (bootstrapping): + - Fetch descriptors aggressively whenever we lack enough to build + circuits, regardless of how many descriptors we are missing. + Previously, we would delay launching the fetch when we had fewer + than 15 missing descriptors, even if some of those descriptors + were blocking circuits from building. Fixes bug 23985; bugfix on + 0.1.1.11-alpha. The effects of this bug became worse in + 0.3.0.3-alpha, when we began treating missing descriptors from our + primary guards as a reason to delay circuits. + + o Major bugfixes (onion services, retry behavior): + - Fix an "off by 2" error in counting rendezvous failures on the + onion service side. While we thought we would stop the rendezvous + attempt after one failed circuit, we were actually making three + circuit attempts before giving up. Now switch to a default of 2, + and allow the consensus parameter "hs_service_max_rdv_failures" to + override. Fixes bug 24895; bugfix on 0.0.6. + + o Minor feature (relay statistics): + - Change relay bandwidth reporting stats interval from 4 hours to 24 + hours in order to reduce the efficiency of guard discovery + attacks. Fixes ticket 23856. + + o Minor features (compatibility, OpenSSL): + - Tor will now support TLS1.3 once OpenSSL 1.1.1 is released. + Previous versions of Tor would not have worked with OpenSSL 1.1.1, + since they neither disabled TLS 1.3 nor enabled any of the + ciphersuites it requires. Now we enable the TLS 1.3 ciphersuites. + Closes ticket 24978. + + o Minor features (denial-of-service avoidance): + - Make our OOM handler aware of the geoip client history cache so it + doesn't fill up the memory. This check is important for IPv6 and + our DoS mitigation subsystem. Closes ticket 25122. + + o Minor features (fallback directory mirrors): + - The fallback directory list has been re-generated based on the + current status of the network. Tor uses fallback directories to + bootstrap when it doesn't yet have up-to-date directory + information. Closes ticket 24801. + - Make the default DirAuthorityFallbackRate 0.1, so that clients + prefer to bootstrap from fallback directory mirrors. This is a + follow-up to 24679, which removed weights from the default + fallbacks. Implements ticket 24681. + + o Minor features (geoip): + - Update geoip and geoip6 to the February 7 2018 Maxmind GeoLite2 + Country database. + + o Minor features (linux seccomp2 sandbox): + - Update the sandbox rules so that they should now work correctly + with Glibc 2.26. Closes ticket 24315. + + o Minor bugfix (channel connection): + - Use the actual observed address of an incoming relay connection, + not the canonical address of the relay from its descriptor, when + making decisions about how to handle the incoming connection. + Fixes bug 24952; bugfix on 0.2.4.11-alpha. Patch by "ffmancera". + + o Minor bugfix (directory authority): + - Directory authorities, when refusing a descriptor from a rejected + relay, now explicitly tell the relay (in its logs) to set a valid + ContactInfo address and contact the bad-relays@ mailing list. + Fixes bug 25170; bugfix on 0.2.9.1. + + o Minor bugfixes (address selection): + - When the fascist_firewall_choose_address_ functions don't find a + reachable address, set the returned address to the null address + and port. This is a precautionary measure, because some callers do + not check the return value. Fixes bug 24736; bugfix + on 0.2.8.2-alpha. + + o Minor bugfixes (compilation): + - Fix a signed/unsigned comparison warning introduced by our fix to + TROVE-2017-009. Fixes bug 24480; bugfix on 0.2.5.16. + + o Minor bugfixes (control port, linux seccomp2 sandbox): + - Avoid a crash when attempting to use the seccomp2 sandbox together + with the OwningControllerProcess feature. Fixes bug 24198; bugfix + on 0.2.5.1-alpha. + + o Minor bugfixes (denial-of-service, backport from 0.3.3.3-alpha): + - Fix a possible crash on malformed consensus. If a consensus had + contained an unparseable protocol line, it could have made clients + and relays crash with a null-pointer exception. To exploit this + issue, however, an attacker would need to be able to subvert the + directory authority system. Fixes bug 25251; bugfix on + 0.2.9.4-alpha. Also tracked as TROVE-2018-004. + + o Minor bugfixes (memory usage): + - When queuing DESTROY cells on a channel, only queue the circuit-id + and reason fields: not the entire 514-byte cell. This fix should + help mitigate any bugs or attacks that fill up these queues, and + free more RAM for other uses. Fixes bug 24666; bugfix + on 0.2.5.1-alpha. + + o Minor bugfixes (network layer): + - When closing a connection via close_connection_immediately(), we + mark it as "not blocked on bandwidth", to prevent later calls from + trying to unblock it, and give it permission to read. This fixes a + backtrace warning that can happen on relays under various + circumstances. Fixes bug 24167; bugfix on 0.1.0.1-rc. + + o Minor bugfixes (OSX): + - Don't exit the Tor process if setrlimit() fails to change the file + limit (which can happen sometimes on some versions of OSX). Fixes + bug 21074; bugfix on 0.0.9pre5. + + o Minor bugfixes (path selection): + - When selecting relays by bandwidth, avoid a rounding error that + could sometimes cause load to be imbalanced incorrectly. + Previously, we would always round upwards; now, we round towards + the nearest integer. This had the biggest effect when a relay's + weight adjustments should have given it weight 0, but it got + weight 1 instead. Fixes bug 23318; bugfix on 0.2.4.3-alpha. + - When calculating the fraction of nodes that have descriptors, and + all nodes in the network have zero bandwidths, count the number of + nodes instead. Fixes bug 23318; bugfix on 0.2.4.10-alpha. + - Actually log the total bandwidth in compute_weighted_bandwidths(). + Fixes bug 24170; bugfix on 0.2.4.3-alpha. + + o Minor bugfixes (portability, msvc): + - Fix a bug in the bit-counting parts of our timing-wheel code on + MSVC. (Note that MSVC is still not a supported build platform, due + to cryptographic timing channel risks.) Fixes bug 24633; bugfix + on 0.2.9.1-alpha. + + o Minor bugfixes (relay): + - Make the internal channel_is_client() function look at what sort + of connection handshake the other side used, rather than whether + the other side ever sent a create_fast cell to us. Backports part + of the fixes from bugs 22805 and 24898. + + o Minor bugfixes (spec conformance, backport from 0.3.3.3-alpha): + - Forbid "-0" as a protocol version. Fixes part of bug 25249; bugfix on + 0.2.9.4-alpha. + - Forbid UINT32_MAX as a protocol version. Fixes part of bug 25249; + bugfix on 0.2.9.4-alpha. + + Changes in version 0.2.9.14 - 2017-12-01 Tor 0.2.9.14 backports important security and stability bugfixes from later Tor releases. All Tor users should upgrade to this release, or