diff --git a/package/libldns/0001-fix-cve-2026-10846.patch b/package/libldns/0001-fix-cve-2026-10846.patch new file mode 100644 index 0000000000..989cd7c958 --- /dev/null +++ b/package/libldns/0001-fix-cve-2026-10846.patch @@ -0,0 +1,225 @@ +From f179ebe97b0c7309edb87a14d6f73119dbecb708 Mon Sep 17 00:00:00 2001 +From: Titouan Christophe +Date: Tue, 1 Sep 2026 19:09:47 +0200 +Subject: [PATCH] Fix CVE-2026-10846 + +== Summary +When ldns is used by applications for (stub) resolving, it does not +sufficiently verify that received responses belong to a sent query. + +== Affected products +ldns 1.2.0 up to and including 1.9.0 + +== Description +NLnet Labs ldns 1.2.0 up to and including versions 1.9.0, when used in +applications as (stub) resolver over UDP, lacks matching the query destination +address and port with the response source address and port. Furthermore not the +query ID, neither the question of the query is matched with that of the +response. This makes applications, that use ldns for (stub) resolver +functionality, vulnerable for off-path poisoning attacks. + +The drill tool, which is shipped with ldns and uses ldns for stub resolving, +inherently suffers from this vulnerability too. + +== Solution +Download a patched version of ldns, or apply the patch manually + +CVE: CVE-2026-10846 +Upstream: https://nlnetlabs.nl/downloads/ldns/patch_cve_2026-10846.diff +Signed-off-by: Titouan Christophe +--- + error.c | 8 +++++ + ldns/error.h | 6 +++- + net.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++-- + 3 files changed, 103 insertions(+), 3 deletions(-) + +diff --git a/error.c b/error.c +index 50cdc630..4fc05d6d 100644 +--- a/error.c ++++ b/error.c +@@ -189,6 +189,14 @@ ldns_lookup_table ldns_error_str[] = { + { LDNS_STATUS_EDE_OPTION_MALFORMED, + "The extended error code option is malformed, expected " + "at least 2 bytes of option data" }, ++ { LDNS_STATUS_EQUAL_RR, ++ "An identical RR already existed in the zone" }, ++ { LDNS_STATUS_ID_DID_NOT_MATCH, ++ "Response ID did not match the query ID" }, ++ { LDNS_STATUS_QDCOUNT_MUST_BE_ONE, ++ "The query section MUST contain exactly one question" }, ++ { LDNS_STATUS_QUERY_DID_NOT_MATCH, ++ "The question in the response did not match the query" }, + { 0, NULL } + }; + +diff --git a/ldns/error.h b/ldns/error.h +index 011df284..41d64cc0 100644 +--- a/ldns/error.h ++++ b/ldns/error.h +@@ -143,7 +143,11 @@ enum ldns_enum_status { + LDNS_STATUS_SVCPARAM_KEY_MORE_THAN_ONCE, + LDNS_STATUS_INVALID_SVCPARAM_VALUE, + LDNS_STATUS_NOT_EDE, +- LDNS_STATUS_EDE_OPTION_MALFORMED ++ LDNS_STATUS_EDE_OPTION_MALFORMED, ++ LDNS_STATUS_EQUAL_RR, ++ LDNS_STATUS_ID_DID_NOT_MATCH, ++ LDNS_STATUS_QDCOUNT_MUST_BE_ONE, ++ LDNS_STATUS_QUERY_DID_NOT_MATCH + }; + typedef enum ldns_enum_status ldns_status; + +diff --git a/net.c b/net.c +index 8fc9c8c4..100226d4 100644 +--- a/net.c ++++ b/net.c +@@ -441,6 +441,50 @@ ldns_udp_bgsend2(ldns_buffer *qbin, + return ldns_udp_bgsend_from(qbin, to, tolen, NULL, 0, timeout); + } + ++/** helper sockaddr compare function. returns -1, 0 or 1. */ ++static int ++ldns_sockaddr_cmp(const struct sockaddr_storage* addr1, socklen_t len1, ++ const struct sockaddr_storage* addr2, socklen_t len2) ++{ ++ struct sockaddr_in* p1_in = (struct sockaddr_in*)addr1; ++ struct sockaddr_in* p2_in = (struct sockaddr_in*)addr2; ++ struct sockaddr_in6* p1_in6 = (struct sockaddr_in6*)addr1; ++ struct sockaddr_in6* p2_in6 = (struct sockaddr_in6*)addr2; ++ if(len1 < len2) ++ return -1; ++ if(len1 > len2) ++ return 1; ++ assert(len1 == len2); ++ if( p1_in->sin_family < p2_in->sin_family) ++ return -1; ++ if( p1_in->sin_family > p2_in->sin_family) ++ return 1; ++ assert( p1_in->sin_family == p2_in->sin_family ); ++ /* compare ip4 */ ++ if( p1_in->sin_family == AF_INET ) { ++ /* just order it, ntohs not required */ ++ if(p1_in->sin_port < p2_in->sin_port) ++ return -1; ++ if(p1_in->sin_port > p2_in->sin_port) ++ return 1; ++ assert(p1_in->sin_port == p2_in->sin_port); ++ return memcmp(&p1_in->sin_addr, &p2_in->sin_addr, ++ sizeof(p1_in->sin_addr)); ++ } else if (p1_in6->sin6_family == AF_INET6) { ++ /* just order it, ntohs not required */ ++ if(p1_in6->sin6_port < p2_in6->sin6_port) ++ return -1; ++ if(p1_in6->sin6_port > p2_in6->sin6_port) ++ return 1; ++ assert(p1_in6->sin6_port == p2_in6->sin6_port); ++ return memcmp(&p1_in6->sin6_addr, &p2_in6->sin6_addr, ++ sizeof(p1_in6->sin6_addr)); ++ } else { ++ /* eek unknown type, perform this comparison for sanity. */ ++ return memcmp(addr1, addr2, len1); ++ } ++} ++ + static ldns_status + ldns_udp_send_from(uint8_t **result, ldns_buffer *qbin, + const struct sockaddr_storage *to , socklen_t tolen, +@@ -449,6 +493,8 @@ ldns_udp_send_from(uint8_t **result, ldns_buffer *qbin, + { + int sockfd; + uint8_t *answer; ++ struct sockaddr_storage reply_addr; ++ socklen_t reply_addr_len; + + sockfd = ldns_udp_bgsend_from(qbin, to, tolen, from, fromlen, timeout); + +@@ -467,13 +513,21 @@ ldns_udp_send_from(uint8_t **result, ldns_buffer *qbin, + * but returns a 'NETWORK_ERROR' much like a timeout. */ + ldns_sock_nonblock(sockfd); + +- answer = ldns_udp_read_wire(sockfd, answer_size, NULL, NULL); ++ reply_addr_len = sizeof(reply_addr); ++ memset(&reply_addr, 0, reply_addr_len); ++ answer = ldns_udp_read_wire(sockfd, answer_size, &reply_addr, ++ &reply_addr_len); + close_socket(sockfd); + + if (!answer) { + /* oops */ + return LDNS_STATUS_NETWORK_ERR; + } ++ /* Check that the reply came from the to addr. */ ++ if(ldns_sockaddr_cmp(to, tolen, &reply_addr, reply_addr_len) != 0) { ++ free(answer); ++ return LDNS_STATUS_NETWORK_ERR; ++ } + + *result = answer; + return LDNS_STATUS_OK; +@@ -512,6 +566,10 @@ ldns_send_buffer(ldns_pkt **result, ldns_resolver *r, ldns_buffer *qb, ldns_rdf + + assert(r != NULL); + ++ /* The query should at least have one question */ ++ if(ldns_buffer_limit(qb) < 6 || ldns_buffer_read_u16_at(qb, 4) != 1) ++ return LDNS_STATUS_QDCOUNT_MUST_BE_ONE; ++ + status = LDNS_STATUS_OK; + rtt = ldns_resolver_rtt(r); + ns_array = ldns_resolver_nameservers(r); +@@ -599,6 +657,16 @@ ldns_send_buffer(ldns_pkt **result, ldns_resolver *r, ldns_buffer *qb, ldns_rdf + ldns_resolver_set_nameserver_rtt(r, i, LDNS_RESOLV_RTT_INF); + status = send_status; + } ++ if(reply_bytes && ldns_buffer_limit(qb) >= 2) { ++ uint16_t txid = ldns_buffer_read_u16_at(qb, 0); ++ if(reply_size < 2 || ++ ldns_read_uint16(reply_bytes) != txid) { ++ status = LDNS_STATUS_ID_DID_NOT_MATCH; ++ LDNS_FREE(reply_bytes); ++ reply_bytes = NULL; ++ reply_size = 0; ++ } ++ } + + /* obey the fail directive */ + if (!reply_bytes) { +@@ -608,7 +676,7 @@ ldns_send_buffer(ldns_pkt **result, ldns_resolver *r, ldns_buffer *qb, ldns_rdf + LDNS_FREE(src); + } + LDNS_FREE(ns); +- return LDNS_STATUS_ERR; ++ return status ? status : LDNS_STATUS_ERR; + } else { + LDNS_FREE(ns); + continue; +@@ -670,6 +738,26 @@ ldns_send_buffer(ldns_pkt **result, ldns_resolver *r, ldns_buffer *qb, ldns_rdf + #endif /* HAVE_SSL */ + + LDNS_FREE(reply_bytes); ++ if (reply) { ++ ldns_pkt *query = NULL; ++ ++ if(ldns_pkt_qdcount(reply) != 1) { ++ status = LDNS_STATUS_QDCOUNT_MUST_BE_ONE; ++ ldns_pkt_free(reply); ++ reply = NULL; ++ ++ } else if(ldns_wire2pkt(&query ++ , ldns_buffer_begin(qb) ++ , ldns_buffer_position(qb)) != LDNS_STATUS_OK ++ || ldns_pkt_qdcount(query) != 1 ++ || ldns_rr_compare(ldns_rr_list_rr(ldns_pkt_question(query),0) ++ ,ldns_rr_list_rr(ldns_pkt_question(reply),0))){ ++ status = LDNS_STATUS_QUERY_DID_NOT_MATCH; ++ ldns_pkt_free(reply); ++ reply = NULL; ++ } ++ ldns_pkt_free(query); ++ } + if (result) { + *result = reply; + } +-- +2.55.0 + diff --git a/package/libldns/libldns.mk b/package/libldns/libldns.mk index 0740d09fab..81ac03b173 100644 --- a/package/libldns/libldns.mk +++ b/package/libldns/libldns.mk @@ -23,6 +23,9 @@ LIBLDNS_CONF_OPTS = \ --without-pyldns \ --without-pyldnsx +# 0001-fix-cve-2026-10846.patch +LIBLDNS_IGNORE_CVES += CVE-2026-10846 + ifeq ($(BR2_PACKAGE_LIBOPENSSL),y) LIBLDNS_CONF_OPTS += --enable-dane-verify else