[tor-talk] Tor 0.2.3.21-rc is out
arma at mit.edu
Wed Sep 5 23:35:50 UTC 2012
Tor 0.2.3.21-rc is the fourth release candidate for the Tor 0.2.3.x
series. It fixes a trio of potential security bugs, fixes a bug where
we were leaving some of the fast relays out of the microdescriptor
consensus, resumes interpreting "ORPort 0" and "DirPort 0" correctly,
and cleans up other smaller issues.
(Packages coming eventually.)
Changes in version 0.2.3.21-rc - 2012-09-05
o Major bugfixes (security):
- Tear down the circuit if we get an unexpected SENDME cell. Clients
could use this trick to make their circuits receive cells faster
than our flow control would have allowed, or to gum up the network,
or possibly to do targeted memory denial-of-service attacks on
entry nodes. Fixes bug 6252. Bugfix on the 54th commit on Tor --
from July 2002, before the release of Tor 0.0.0. We had committed
this patch previously, but we had to revert it because of bug 6271.
Now that 6271 is fixed, this patch appears to work.
- Reject any attempt to extend to an internal address. Without
this fix, a router could be used to probe addresses on an internal
network to see whether they were accepting connections. Fixes bug
6710; bugfix on 0.0.8pre1.
- Do not crash when comparing an address with port value 0 to an
address policy. This bug could have been used to cause a remote
assertion failure by or against directory authorities, or to
allow some applications to crash clients. Fixes bug 6690; bugfix
o Major bugfixes:
- Remove the upper bound on microdescriptor length. We were hitting
the limit for routers with complex exit policies or family
declarations, causing clients to not use them. Fixes the first
piece of bug 6404; fix on 0.2.2.6-alpha.
- Detect "ORPort 0" as meaning, uniformly, that we're not running
as a relay. Previously, some of our code would treat the presence
of any ORPort line as meaning that we should act like a relay,
even though our new listener code would correctly not open any
ORPorts for ORPort 0. Similar bugs in other Port options are also
fixed. Fixes the first half of bug 6507; bugfix on 0.2.3.3-alpha.
o Minor bugfixes:
- Avoid a pair of double-free and use-after-mark bugs that can
occur with certain timings in canceled and re-received DNS
requests. Fixes bug 6472; bugfix on 0.0.7rc1.
- Fix build and 64-bit compile warnings from --enable-openbsd-malloc.
Fixes bug 6379. Bugfix on 0.2.0.20-rc.
- Allow one-hop directory fetching circuits the full "circuit build
timeout" period, rather than just half of it, before failing them
and marking the relay down. This fix should help reduce cases where
clients declare relays (or worse, bridges) unreachable because
the TLS handshake takes a few seconds to complete. Fixes bug 6743;
bugfix on 0.2.2.2-alpha, where we changed the timeout from a static
- Authorities no longer include any router in their microdescriptor
consensuses for which they couldn't generate or agree on a
microdescriptor. Fixes the second piece of bug 6404; fix on
- Detect and reject attempts to specify both "FooPort" and
"FooPort 0" in the same configuration domain. (It's still okay
to have a FooPort in your configuration file, and use "FooPort 0"
on the command line to disable it.) Fixes the second half of bug
6507; bugfix on 0.2.3.3-alpha.
- Make wildcarded addresses (that is, ones beginning with "*.") work
when provided via the controller's MapAddress command. Previously,
they were accepted, but we never actually noticed that they were
wildcards. Fixes bug 6244; bugfix on 0.2.3.9-alpha.
- Avoid crashing on a malformed state file where EntryGuardPathBias
precedes EntryGuard. Fixes bug 6774; bugfix on 0.2.3.17-beta.
- Add a (probably redundant) memory clear between iterations of
the router status voting loop, to prevent future coding errors
where data might leak between iterations of the loop. Resolves
o Minor bugfixes (log messages):
- Downgrade "set buildtimeout to low value" messages to "info"
severity; they were never an actual problem, there was never
anything reasonable to do about them, and they tended to spam logs
from time to time. Fixes bug 6251; bugfix on 0.2.2.2-alpha.
- Downgrade path-bias warning messages to "info". We'll try to get
them working better in 0.2.4. Add internal circuit construction
state to protect against the noisy warn message "Unexpectedly high
circuit_successes". Also add some additional rate-limited notice
messages to help determine the root cause of the warn. Fixes bug
6475. Bugfix against 0.2.3.17-beta.
- Move log message when unable to find a microdesc in a routerstatus
entry to parse time. Previously we'd spam this warning every time
we tried to figure out which microdescriptors to download. Fixes
the third piece of bug 6404; fix on 0.2.3.18-rc.
o Minor features:
- Consider new, removed or changed IPv6 OR ports a non-cosmetic
change when the authority is deciding whether to accept a newly
uploaded descriptor. Implements ticket 6423.
- Add missing documentation for consensus and microdesc files.
Resolves ticket 6732.
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