commit bf3e32a45288b64e5535e02f40bd2bcb93c8a520 Author: John Brooks special@torproject.org Date: Wed May 11 12:13:22 2016 -0400
Fix out-of-bounds write during voting with duplicate ed25519 keys
In dirserv_compute_performance_thresholds, we allocate arrays based on the length of 'routers', a list of routerinfo_t, but loop over the nodelist. The 'routers' list may be shorter when relays were filtered by routers_make_ed_keys_unique, leading to an out-of-bounds write on directory authorities.
This bug was originally introduced in 26e89742, but it doesn't look possible to trigger until routers_make_ed_keys_unique was introduced in 13a31e72.
Fixes bug 19032; bugfix on tor 0.2.8.2-alpha. --- changes/bug19032 | 4 ++++ src/or/dirserv.c | 31 ++++++++++++++++--------------- src/or/dirserv.h | 2 +- src/or/networkstatus.c | 3 +-- 4 files changed, 22 insertions(+), 18 deletions(-)
diff --git a/changes/bug19032 b/changes/bug19032 new file mode 100644 index 0000000..93f17c2 --- /dev/null +++ b/changes/bug19032 @@ -0,0 +1,4 @@ + o Major bugfixes (security, directory authorities): + - Fix a crash and out-of-bounds write during authority voting, when the + list of relays includes duplicate ed25519 identity keys. Fixes bug 19032; + bugfix on 0.2.8.2-alpha. diff --git a/src/or/dirserv.c b/src/or/dirserv.c index ae67e8e..a367669 100644 --- a/src/or/dirserv.c +++ b/src/or/dirserv.c @@ -1422,13 +1422,13 @@ router_counts_toward_thresholds(const node_t *node, time_t now, * * Also, set the is_exit flag of each router appropriately. */ static void -dirserv_compute_performance_thresholds(const smartlist_t *routers, - digestmap_t *omit_as_sybil) +dirserv_compute_performance_thresholds(digestmap_t *omit_as_sybil) { int n_active, n_active_nonexit, n_familiar; uint32_t *uptimes, *bandwidths_kb, *bandwidths_excluding_exits_kb; long *tks; double *mtbfs, *wfus; + smartlist_t *nodelist; time_t now = time(NULL); const or_options_t *options = get_options();
@@ -1446,27 +1446,28 @@ dirserv_compute_performance_thresholds(const smartlist_t *routers, guard_tk = 0; guard_wfu = 0;
+ nodelist_assert_ok(); + nodelist = nodelist_get_list(); + /* Initialize arrays that will hold values for each router. We'll * sort them and use that to compute thresholds. */ n_active = n_active_nonexit = 0; /* Uptime for every active router. */ - uptimes = tor_calloc(smartlist_len(routers), sizeof(uint32_t)); + uptimes = tor_calloc(smartlist_len(nodelist), sizeof(uint32_t)); /* Bandwidth for every active router. */ - bandwidths_kb = tor_calloc(smartlist_len(routers), sizeof(uint32_t)); + bandwidths_kb = tor_calloc(smartlist_len(nodelist), sizeof(uint32_t)); /* Bandwidth for every active non-exit router. */ bandwidths_excluding_exits_kb = - tor_calloc(smartlist_len(routers), sizeof(uint32_t)); + tor_calloc(smartlist_len(nodelist), sizeof(uint32_t)); /* Weighted mean time between failure for each active router. */ - mtbfs = tor_calloc(smartlist_len(routers), sizeof(double)); + mtbfs = tor_calloc(smartlist_len(nodelist), sizeof(double)); /* Time-known for each active router. */ - tks = tor_calloc(smartlist_len(routers), sizeof(long)); + tks = tor_calloc(smartlist_len(nodelist), sizeof(long)); /* Weighted fractional uptime for each active router. */ - wfus = tor_calloc(smartlist_len(routers), sizeof(double)); - - nodelist_assert_ok(); + wfus = tor_calloc(smartlist_len(nodelist), sizeof(double));
/* Now, fill in the arrays. */ - SMARTLIST_FOREACH_BEGIN(nodelist_get_list(), node_t *, node) { + SMARTLIST_FOREACH_BEGIN(nodelist, node_t *, node) { if (options->BridgeAuthoritativeDir && node->ri && node->ri->purpose != ROUTER_PURPOSE_BRIDGE) @@ -1542,7 +1543,7 @@ dirserv_compute_performance_thresholds(const smartlist_t *routers, * fill wfus with the wfu of every such "familiar" router. */ n_familiar = 0;
- SMARTLIST_FOREACH_BEGIN(nodelist_get_list(), node_t *, node) { + SMARTLIST_FOREACH_BEGIN(nodelist, node_t *, node) { if (router_counts_toward_thresholds(node, now, omit_as_sybil, require_mbw)) { routerinfo_t *ri = node->ri; @@ -1596,11 +1597,11 @@ dirserv_compute_performance_thresholds(const smartlist_t *routers, * networkstatus_getinfo_by_purpose(). */ void -dirserv_compute_bridge_flag_thresholds(const smartlist_t *routers) +dirserv_compute_bridge_flag_thresholds() {
digestmap_t *omit_as_sybil = digestmap_new(); - dirserv_compute_performance_thresholds(routers, omit_as_sybil); + dirserv_compute_performance_thresholds(omit_as_sybil); digestmap_free(omit_as_sybil, NULL); }
@@ -2870,7 +2871,7 @@ dirserv_generate_networkstatus_vote_obj(crypto_pk_t *private_key, * this must come before dirserv_compute_performance_thresholds() */ dirserv_count_measured_bws(routers);
- dirserv_compute_performance_thresholds(routers, omit_as_sybil); + dirserv_compute_performance_thresholds(omit_as_sybil);
routerstatuses = smartlist_new(); microdescriptors = smartlist_new(); diff --git a/src/or/dirserv.h b/src/or/dirserv.h index b16a67c..4bb3072 100644 --- a/src/or/dirserv.h +++ b/src/or/dirserv.h @@ -50,7 +50,7 @@ int list_server_status_v1(smartlist_t *routers, char **router_status_out, int dirserv_dump_directory_to_string(char **dir_out, crypto_pk_t *private_key); char *dirserv_get_flag_thresholds_line(void); -void dirserv_compute_bridge_flag_thresholds(const smartlist_t *routers); +void dirserv_compute_bridge_flag_thresholds(void);
int directory_fetches_from_authorities(const or_options_t *options); int directory_fetches_dir_info_early(const or_options_t *options); diff --git a/src/or/networkstatus.c b/src/or/networkstatus.c index a9b22ed..f72e9d5 100644 --- a/src/or/networkstatus.c +++ b/src/or/networkstatus.c @@ -1697,11 +1697,10 @@ networkstatus_dump_bridge_status_to_file(time_t now) char *fname = NULL; char *thresholds = NULL; char *published_thresholds_and_status = NULL; - routerlist_t *rl = router_get_routerlist(); char published[ISO_TIME_LEN+1];
format_iso_time(published, now); - dirserv_compute_bridge_flag_thresholds(rl->routers); + dirserv_compute_bridge_flag_thresholds(); thresholds = dirserv_get_flag_thresholds_line(); tor_asprintf(&published_thresholds_and_status, "published %s\nflag-thresholds %s\n%s",