commit b5bfdbfd41e38ac73d6655ff3da5a06b66f54d8a Author: rl1987 rl1987@sdf.lonestar.org Date: Wed Apr 8 18:07:14 2020 +0300

Check output value of tor_inet_ntop/tor_inet_ntoa in dns.c --- src/feature/relay/dns.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/src/feature/relay/dns.c b/src/feature/relay/dns.c index 4dcf5b703..26e9c6bf1 100644 --- a/src/feature/relay/dns.c +++ b/src/feature/relay/dns.c @@ -1591,12 +1591,17 @@ evdns_callback(int result, char type, int count, int ttl, void *addresses, } else if (type == DNS_IPv6_AAAA && count) { char answer_buf[TOR_ADDR_BUF_LEN]; char *escaped_address; + const char *ip_str; struct in6_addr *addrs = addresses; tor_addr_from_in6(&addr, &addrs[0]); - tor_inet_ntop(AF_INET6, &addrs[0], answer_buf, sizeof(answer_buf)); + ip_str = tor_inet_ntop(AF_INET6, &addrs[0], answer_buf, + sizeof(answer_buf)); escaped_address = esc_for_log(string_address);

- if (answer_is_wildcarded(answer_buf)) { + if (BUG(ip_str == NULL)) { + log_warn(LD_EXIT, "tor_inet_ntop() failed!"); + result = DNS_ERR_NOTEXIST; + } else if (answer_is_wildcarded(answer_buf)) { log_debug(LD_EXIT, "eventdns said that %s resolves to ISP-hijacked " "address %s; treating as a failure.", safe_str(escaped_address), @@ -1863,6 +1868,7 @@ evdns_wildcard_check_callback(int result, char type, int count, int ttl, void *addresses, void *arg) { (void)ttl; + const char *ip_str; ++n_wildcard_requests; if (result == DNS_ERR_NONE && count) { char *string_address = arg; @@ -1872,16 +1878,22 @@ evdns_wildcard_check_callback(int result, char type, int count, int ttl, for (i = 0; i < count; ++i) { char answer_buf[INET_NTOA_BUF_LEN+1]; struct in_addr in; + int ntoa_res; in.s_addr = addrs[i]; - tor_inet_ntoa(&in, answer_buf, sizeof(answer_buf)); - wildcard_increment_answer(answer_buf); + ntoa_res = tor_inet_ntoa(&in, answer_buf, sizeof(answer_buf)); + tor_assert_nonfatal(ntoa_res > 0); + if (ntoa_res > 0) + wildcard_increment_answer(answer_buf); } } else if (type == DNS_IPv6_AAAA) { const struct in6_addr *addrs = addresses; for (i = 0; i < count; ++i) { char answer_buf[TOR_ADDR_BUF_LEN+1]; - tor_inet_ntop(AF_INET6, &addrs[i], answer_buf, sizeof(answer_buf)); - wildcard_increment_answer(answer_buf); + ip_str = tor_inet_ntop(AF_INET6, &addrs[i], answer_buf, + sizeof(answer_buf)); + tor_assert_nonfatal(ip_str); + if (ip_str) + wildcard_increment_answer(answer_buf); } }