tor

commit 6ab07419c88e35c6d8610e20fb3cea16e39c8acd
parent 831d3b794da65b03be7e4fd107ba209d7211de76
Author: David Goulet <dgoulet@torproject.org>
Date:   Tue, 28 Nov 2017 19:02:00 -0500

Use local descriptor object to exclude self in path selection

TROVE-2017-12. Severity: Medium

When choosing a random node for a circuit, directly use our router
descriptor to exclude ourself instead of the one in the global
descriptor list. That list could be empty because tor could be
downloading them which could lead to not excluding ourself.

Closes #21534

Diffstat:
A
changes/trove-2017-012-part1
 | 
6
++++++
M
src/or/routerlist.c
 | 
5
++++-

2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/changes/trove-2017-012-part1 b/changes/trove-2017-012-part1
@@ -0,0 +1,6 @@
+  o Major bugfixes (security, relay):
+    - When running as a relay, make sure that we never build a path through
+      ourselves, even in the case where we have somehow lost the version of
+      our descriptor appearing in the consensus. Fixes part of bug 21534;
+      bugfix on 0.2.0.1-alpha. This issue is also tracked as TROVE-2017-012
+      and CVE-2017-8822.
diff --git a/src/or/routerlist.c b/src/or/routerlist.c
@@ -2411,7 +2411,10 @@ router_choose_random_node(smartlist_t *excludedsmartlist,
       });
   }
 
-  if ((r = routerlist_find_my_routerinfo()))
+  /* If the node_t is not found we won't be to exclude ourself but we
+   * won't be able to pick ourself in router_choose_random_node() so
+   * this is fine to at least try with our routerinfo_t object. */
+  if ((r = router_get_my_routerinfo()))
     routerlist_add_node_and_family(excludednodes, r);
 
   router_add_running_nodes_to_smartlist(sl, allow_invalid,