1From b9b8413cfdb70a3f99e1573333b23052d57ec1ae Mon Sep 17 00:00:00 2001 2From: Brad House <brad@brad-house.com> 3Date: Mon, 22 May 2023 06:51:49 -0400 4Subject: [PATCH] Merge pull request from GHSA-9g78-jv2r-p7vc 5 6--- 7 src/lib/ares_process.c | 41 +++++++++++++++++++++++++---------------- 8 1 file changed, 25 insertions(+), 16 deletions(-) 9 10diff --git a/src/lib/ares_process.c b/src/lib/ares_process.c 11index bf0cde4..6cac0a9 100644 12--- a/src/lib/ares_process.c 13+++ b/src/lib/ares_process.c 14@@ -470,7 +470,7 @@ static void read_udp_packets(ares_channel channel, fd_set *read_fds, 15 { 16 struct server_state *server; 17 int i; 18- ares_ssize_t count; 19+ ares_ssize_t read_len; 20 unsigned char buf[MAXENDSSZ + 1]; 21 #ifdef HAVE_RECVFROM 22 ares_socklen_t fromlen; 23@@ -513,32 +513,41 @@ static void read_udp_packets(ares_channel channel, fd_set *read_fds, 24 /* To reduce event loop overhead, read and process as many 25 * packets as we can. */ 26 do { 27- if (server->udp_socket == ARES_SOCKET_BAD) 28- count = 0; 29- 30- else { 31- if (server->addr.family == AF_INET) 32+ if (server->udp_socket == ARES_SOCKET_BAD) { 33+ read_len = -1; 34+ } else { 35+ if (server->addr.family == AF_INET) { 36 fromlen = sizeof(from.sa4); 37- else 38+ } else { 39 fromlen = sizeof(from.sa6); 40- count = socket_recvfrom(channel, server->udp_socket, (void *)buf, 41- sizeof(buf), 0, &from.sa, &fromlen); 42+ } 43+ read_len = socket_recvfrom(channel, server->udp_socket, (void *)buf, 44+ sizeof(buf), 0, &from.sa, &fromlen); 45 } 46 47- if (count == -1 && try_again(SOCKERRNO)) 48+ if (read_len == 0) { 49+ /* UDP is connectionless, so result code of 0 is a 0-length UDP 50+ * packet, and not an indication the connection is closed like on 51+ * tcp */ 52 continue; 53- else if (count <= 0) 54+ } else if (read_len < 0) { 55+ if (try_again(SOCKERRNO)) 56+ continue; 57+ 58 handle_error(channel, i, now); 59+ 60 #ifdef HAVE_RECVFROM 61- else if (!same_address(&from.sa, &server->addr)) 62+ } else if (!same_address(&from.sa, &server->addr)) { 63 /* The address the response comes from does not match the address we 64 * sent the request to. Someone may be attempting to perform a cache 65 * poisoning attack. */ 66- break; 67+ continue; 68 #endif 69- else 70- process_answer(channel, buf, (int)count, i, 0, now); 71- } while (count > 0); 72+ 73+ } else { 74+ process_answer(channel, buf, (int)read_len, i, 0, now); 75+ } 76+ } while (read_len >= 0); 77 } 78 } 79 80-- 812.27.0 82 83