From e3f3478032921a8b6af07a655fd2ea520d3ff463 Mon Sep 17 00:00:00 2001 From: David Goulet Date: Tue, 18 Jun 2019 13:32:45 -0400 Subject: [PATCH] guard: Ignore marked for close circuit when changing state to open When we consider all circuits in "waiting for guard" state to be promoted to an "open" state, we were considering all circuits, even the one marked for close. This ultiamtely triggers a "circuit_has_opened()" called on the circuit that is marked for close which then leads to possible undesirable behaviors within a subsystem. For instance, the HS subsystem would be unable to find the authentication key of the introduction point circuit leading to a BUG() warning and a duplicate mark for close on the circuit. This commit also adds a unit test to make sure we never select marked for close circuits when upgrading its guard state from waiting for guard to open. Fixes #30871 Signed-off-by: David Goulet --- changes/ticket30871 | 6 +++++ src/feature/client/entrynodes.c | 4 +++ src/test/test_circuitbuild.c | 47 +++++++++++++++++++++++++++++++++ 3 files changed, 57 insertions(+) create mode 100644 changes/ticket30871 diff --git a/changes/ticket30871 b/changes/ticket30871 new file mode 100644 index 0000000000..81c076bb02 --- /dev/null +++ b/changes/ticket30871 @@ -0,0 +1,6 @@ + o Major bugfixes (circuit build, guard): + - When considering upgrading circuits from "waiting for guard" to "open", + always ignore the ones that are mark for close. Else, we can end up in + the situation where a subsystem is notified of that circuit opening but + still marked for close leading to undesirable behavior. Fixes bug 30871; + bugfix on 0.3.0.1-alpha. diff --git a/src/feature/client/entrynodes.c b/src/feature/client/entrynodes.c index e543289ce0..d191f58367 100644 --- a/src/feature/client/entrynodes.c +++ b/src/feature/client/entrynodes.c @@ -2611,6 +2611,10 @@ entry_guards_upgrade_waiting_circuits(guard_selection_t *gs, entry_guard_t *guard = entry_guard_handle_get(state->guard); if (!guard || guard->in_selection != gs) continue; + if (TO_CIRCUIT(circ)->marked_for_close) { + /* Don't consider any marked for close circuits. */ + continue; + } smartlist_add(all_circuits, circ); } SMARTLIST_FOREACH_END(circ); diff --git a/src/test/test_circuitbuild.c b/src/test/test_circuitbuild.c index 275f1eced2..538f20781f 100644 --- a/src/test/test_circuitbuild.c +++ b/src/test/test_circuitbuild.c @@ -4,6 +4,8 @@ /* See LICENSE for licensing information */ #define CIRCUITBUILD_PRIVATE +#define CIRCUITLIST_PRIVATE +#define ENTRYNODES_PRIVATE #include "core/or/or.h" #include "test/test.h" @@ -13,7 +15,11 @@ #include "core/or/circuitbuild.h" #include "core/or/circuitlist.h" +#include "core/or/cpath_build_state_st.h" #include "core/or/extend_info_st.h" +#include "core/or/origin_circuit_st.h" + +#include "feature/client/entrynodes.h" /* Dummy nodes smartlist for testing */ static smartlist_t dummy_nodes; @@ -126,10 +132,51 @@ test_new_route_len_unhandled_exit(void *arg) UNMOCK(count_acceptable_nodes); } +static void +test_upgrade_from_guard_wait(void *arg) +{ + circuit_t *circ = NULL; + origin_circuit_t *orig_circ = NULL; + entry_guard_t *guard = NULL; + smartlist_t *list = NULL; + + (void) arg; + + circ = dummy_origin_circuit_new(0); + orig_circ = TO_ORIGIN_CIRCUIT(circ); + tt_assert(orig_circ); + + orig_circ->build_state = tor_malloc_zero(sizeof(cpath_build_state_t)); + + circuit_set_state(circ, CIRCUIT_STATE_GUARD_WAIT); + + /* Put it in guard wait state. */ + guard = tor_malloc_zero(sizeof(*guard)); + guard->in_selection = get_guard_selection_info(); + + orig_circ->guard_state = + circuit_guard_state_new(guard, GUARD_CIRC_STATE_WAITING_FOR_BETTER_GUARD, + NULL); + + /* Mark the circuit for close. */ + circuit_mark_for_close(circ, END_CIRC_REASON_TORPROTOCOL); + tt_int_op(circ->marked_for_close, OP_NE, 0); + + /* We shouldn't pick the mark for close circuit. */ + list = circuit_find_circuits_to_upgrade_from_guard_wait(); + tt_assert(!list); + + done: + circuit_free(circ); + entry_guard_free_(guard); +} + struct testcase_t circuitbuild_tests[] = { { "noexit", test_new_route_len_noexit, 0, NULL, NULL }, { "safe_exit", test_new_route_len_safe_exit, 0, NULL, NULL }, { "unsafe_exit", test_new_route_len_unsafe_exit, 0, NULL, NULL }, { "unhandled_exit", test_new_route_len_unhandled_exit, 0, NULL, NULL }, + { "upgrade_from_guard_wait", test_upgrade_from_guard_wait, TT_FORK, + NULL, NULL }, END_OF_TESTCASES };