diff --git a/ReleaseNotes b/ReleaseNotes index bbda36d2c..d36f87eea 100644 --- a/ReleaseNotes +++ b/ReleaseNotes @@ -637,6 +637,413 @@ Changes in version 0.3.3.6 - 2018-05-22 ticket 25248. +Changes in version 0.3.1.10 - 2018-03-03 + Tor 0.3.1.10 backports a number of bugfixes, including important fixes for + security issues. + + 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 0.3.1.x may wish to update to one of + the versions released today, for the DoS mitigations. + + Please note: according to our release calendar, Tor 0.3.1 will no + longer be supported after 1 July 2018. If you will be running Tor + after that date, you should make sure to plan to upgrade to the latest + stable version, or downgrade to 0.2.9 (which will receive long-term + support). + + 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, backport from 0.3.3.2-alpha): + - 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 Minor features (linux seccomp2 sandbox, backport from 0.3.2.5-alpha): + - Update the sandbox rules so that they should now work correctly + with Glibc 2.26. Closes ticket 24315. + + o Major bugfixes (onion services, retry behavior, backport from 0.3.3.1-alpha): + - 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 Major bugfixes (protocol versions, backport from 0.3.3.2-alpha): + - Add Link protocol version 5 to the supported protocols list. Fixes + bug 25070; bugfix on 0.3.1.1-alpha. + + o Major bugfixes (relay, backport from 0.3.3.1-alpha): + - Fix a set of false positives where relays would consider + connections to other relays as being client-only connections (and + thus e.g. deserving different link padding schemes) if those + relays fell out of the consensus briefly. Now we look only at the + initial handshake and whether the connection authenticated as a + relay. Fixes bug 24898; bugfix on 0.3.1.1-alpha. + + o Minor features (denial-of-service avoidance, backport from 0.3.3.2-alpha): + - 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 feature (relay statistics, backport from 0.3.2.6-alpha): + - 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, backport from 0.3.3.3-alpha): + - 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 (fallback directory mirrors, backport from 0.3.2.9): + - 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 bugfix (channel connection, backport from 0.3.3.2-alpha): + - 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, backport from 0.3.3.2-alpha): + - 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, backport from 0.3.2.9): + - 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 Major bugfixes (bootstrapping, backport from 0.3.2.5-alpha): + - 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. + - Don't try fetching microdescriptors from relays that have failed + to deliver them in the past. Fixes bug 23817; bugfix + on 0.3.0.1-alpha. + + o Minor bugfixes (compilation, backport from 0.3.2.7-rc): + - 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, backport from 0.3.2.5-alpha): + - 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 (directory cache, backport from 0.3.2.5-alpha): + - Recover better from empty or corrupt files in the consensus cache + directory. Fixes bug 24099; bugfix on 0.3.1.1-alpha. + - When a consensus diff calculation is only partially successful, + only record the successful parts as having succeeded. Partial + success can happen if (for example) one compression method fails + but the others succeed. Previously we misrecorded all the + calculations as having succeeded, which would later cause a + nonfatal assertion failure. Fixes bug 24086; bugfix + on 0.3.1.1-alpha. + + o Minor bugfixes (entry guards, backport from 0.3.2.3-alpha): + - Tor now updates its guard state when it reads a consensus + regardless of whether it's missing descriptors. That makes tor use + its primary guards to fetch descriptors in some edge cases where + it would previously have used fallback directories. Fixes bug + 23862; bugfix on 0.3.0.1-alpha. + + o Minor bugfixes (logging, backport from 0.3.3.2-alpha): + - Don't treat inability to store a cached consensus object as a bug: + it can happen normally when we are out of disk space. Fixes bug + 24859; bugfix on 0.3.1.1-alpha. + + o Minor bugfixes (memory usage, backport from 0.3.2.8-rc): + - 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, backport from 0.3.2.5-alpha): + - 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 (path selection, backport from 0.3.2.4-alpha): + - 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 (performance, fragile-hardening, backport from 0.3.3.1-alpha): + - Improve the performance of our consensus-diff application code + when Tor is built with the --enable-fragile-hardening option set. + Fixes bug 24826; bugfix on 0.3.1.1-alpha. + + o Minor bugfixes (OSX, backport from 0.3.3.1-alpha): + - 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 (portability, msvc, backport from 0.3.2.9): + - 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 cyptographic timing channel risks.) Fixes bug 24633; bugfix + on 0.2.9.1-alpha. + + o Minor bugfixes (relay, partial backport): + - 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. + + o Code simplification and refactoring (backport from 0.3.3.3-alpha): + - Update the "rust dependencies" submodule to be a project-level + repository, rather than a user repository. Closes ticket 25323. + + +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 0.3.2.10 - 2018-03-03 Tor 0.3.2.10 is the second stable release in the 0.3.2 series. It backports a number of bugfixes, including important fixes for security