From 3b2fe2b8e646a98ab617468d8c9854c61a6197d1 Mon Sep 17 00:00:00 2001 From: Dmitry Belyavskiy Date: Tue, 18 Feb 2025 10:59:20 +0100 Subject: [PATCH] OpenSSH error code issues Fix missing error codes set and invalid error code checks in OpenSSH. It prevents memory exhaustion attack and a MITM attack when VerifyHostKeyDNS is on (CVE-2025-26465, CVE-2025-26466). Resolves: RHEL-78699 Resolves: RHEL-78943 --- openssh-9.9p2-error_processing.patch | 152 +++++++++++++++++++++++++++ openssh.spec | 9 ++ 2 files changed, 161 insertions(+) create mode 100644 openssh-9.9p2-error_processing.patch diff --git a/openssh-9.9p2-error_processing.patch b/openssh-9.9p2-error_processing.patch new file mode 100644 index 0000000..692c6ac --- /dev/null +++ b/openssh-9.9p2-error_processing.patch @@ -0,0 +1,152 @@ +diff --git a/krl.c b/krl.c +index e2efdf06..0d0f6953 100644 +--- a/krl.c ++++ b/krl.c +@@ -674,6 +674,7 @@ revoked_certs_generate(struct revoked_certs *rc, struct sshbuf *buf) + break; + case KRL_SECTION_CERT_SERIAL_BITMAP: + if (rs->lo - bitmap_start > INT_MAX) { ++ r = SSH_ERR_INVALID_FORMAT; + error_f("insane bitmap gap"); + goto out; + } +@@ -1059,6 +1060,7 @@ ssh_krl_from_blob(struct sshbuf *buf, struct ssh_krl **krlp) + } + + if ((krl = ssh_krl_init()) == NULL) { ++ r = SSH_ERR_ALLOC_FAIL; + error_f("alloc failed"); + goto out; + } +diff --git a/packet.c b/packet.c +index 486f8515..9dea2cfc 100644 +--- a/packet.c ++++ b/packet.c +@@ -1864,6 +1864,14 @@ ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p) + if ((r = sshpkt_get_string_direct(ssh, &d, &len)) != 0) + return r; + DBG(debug("Received SSH2_MSG_PING len %zu", len)); ++ if (!ssh->state->after_authentication) { ++ DBG(debug("Won't reply to PING in preauth")); ++ break; ++ } ++ if (ssh_packet_is_rekeying(ssh)) { ++ DBG(debug("Won't reply to PING during KEX")); ++ break; ++ } + if ((r = sshpkt_start(ssh, SSH2_MSG_PONG)) != 0 || + (r = sshpkt_put_string(ssh, d, len)) != 0 || + (r = sshpkt_send(ssh)) != 0) +diff --git a/ssh-agent.c b/ssh-agent.c +index 48973b2c..c27c5a95 100644 +--- a/ssh-agent.c ++++ b/ssh-agent.c +@@ -1220,6 +1220,7 @@ parse_key_constraint_extension(struct sshbuf *m, char **sk_providerp, + "restrict-destination-v00@openssh.com") == 0) { + if (*dcsp != NULL) { + error_f("%s already set", ext_name); ++ r = SSH_ERR_INVALID_FORMAT; + goto out; + } + if ((r = sshbuf_froms(m, &b)) != 0) { +@@ -1229,6 +1230,7 @@ parse_key_constraint_extension(struct sshbuf *m, char **sk_providerp, + while (sshbuf_len(b) != 0) { + if (*ndcsp >= AGENT_MAX_DEST_CONSTRAINTS) { + error_f("too many %s constraints", ext_name); ++ r = SSH_ERR_INVALID_FORMAT; + goto out; + } + *dcsp = xrecallocarray(*dcsp, *ndcsp, *ndcsp + 1, +@@ -1246,6 +1248,7 @@ parse_key_constraint_extension(struct sshbuf *m, char **sk_providerp, + } + if (*certs != NULL) { + error_f("%s already set", ext_name); ++ r = SSH_ERR_INVALID_FORMAT; + goto out; + } + if ((r = sshbuf_get_u8(m, &v)) != 0 || +@@ -1257,6 +1260,7 @@ parse_key_constraint_extension(struct sshbuf *m, char **sk_providerp, + while (sshbuf_len(b) != 0) { + if (*ncerts >= AGENT_MAX_EXT_CERTS) { + error_f("too many %s constraints", ext_name); ++ r = SSH_ERR_INVALID_FORMAT; + goto out; + } + *certs = xrecallocarray(*certs, *ncerts, *ncerts + 1, +@@ -1757,6 +1761,7 @@ process_ext_session_bind(SocketEntry *e) + /* record new key/sid */ + if (e->nsession_ids >= AGENT_MAX_SESSION_IDS) { + error_f("too many session IDs recorded"); ++ r = -1; + goto out; + } + e->session_ids = xrecallocarray(e->session_ids, e->nsession_ids, +diff --git a/ssh-sk-client.c b/ssh-sk-client.c +index 321fe53a..06fad221 100644 +--- a/ssh-sk-client.c ++++ b/ssh-sk-client.c +@@ -439,6 +439,7 @@ sshsk_load_resident(const char *provider_path, const char *device, + } + if ((srk = calloc(1, sizeof(*srk))) == NULL) { + error_f("calloc failed"); ++ r = SSH_ERR_ALLOC_FAIL; + goto out; + } + srk->key = key; +@@ -450,6 +451,7 @@ sshsk_load_resident(const char *provider_path, const char *device, + if ((tmp = recallocarray(srks, nsrks, nsrks + 1, + sizeof(*srks))) == NULL) { + error_f("recallocarray keys failed"); ++ r = SSH_ERR_ALLOC_FAIL; + goto out; + } + debug_f("srks[%zu]: %s %s uidlen %zu", nsrks, +diff --git a/sshconnect2.c b/sshconnect2.c +index a69c4da1..1ee6000a 100644 +--- a/sshconnect2.c ++++ b/sshconnect2.c +@@ -99,7 +99,7 @@ verify_host_key_callback(struct sshkey *hostkey, struct ssh *ssh) + options.required_rsa_size)) != 0) + fatal_r(r, "Bad server host key"); + if (verify_host_key(xxx_host, xxx_hostaddr, hostkey, +- xxx_conn_info) == -1) ++ xxx_conn_info) != 0) + fatal("Host key verification failed."); + return 0; + } +@@ -699,6 +699,7 @@ input_userauth_pk_ok(int type, u_int32_t seq, struct ssh *ssh) + + if ((pktype = sshkey_type_from_name(pkalg)) == KEY_UNSPEC) { + debug_f("server sent unknown pkalg %s", pkalg); ++ r = SSH_ERR_INVALID_FORMAT; + goto done; + } + if ((r = sshkey_from_blob(pkblob, blen, &key)) != 0) { +@@ -709,6 +710,7 @@ input_userauth_pk_ok(int type, u_int32_t seq, struct ssh *ssh) + error("input_userauth_pk_ok: type mismatch " + "for decoded key (received %d, expected %d)", + key->type, pktype); ++ r = SSH_ERR_INVALID_FORMAT; + goto done; + } + +@@ -728,6 +730,7 @@ input_userauth_pk_ok(int type, u_int32_t seq, struct ssh *ssh) + SSH_FP_DEFAULT); + error_f("server replied with unknown key: %s %s", + sshkey_type(key), fp == NULL ? "" : fp); ++ r = SSH_ERR_INVALID_FORMAT; + goto done; + } + ident = format_identity(id); +diff --git a/sshsig.c b/sshsig.c +index 6e03c0b0..3da005d6 100644 +--- a/sshsig.c ++++ b/sshsig.c +@@ -879,6 +879,7 @@ cert_filter_principals(const char *path, u_long linenum, + } + if ((principals = sshbuf_dup_string(nprincipals)) == NULL) { + error_f("buffer error"); ++ r = SSH_ERR_ALLOC_FAIL; + goto out; + } + /* success */ diff --git a/openssh.spec b/openssh.spec index e87ae6f..5056da7 100644 --- a/openssh.spec +++ b/openssh.spec @@ -202,6 +202,9 @@ Patch1019: openssh-9.9p1-mlkembe.patch # upstream 3f02368e8e9121847727c46b280efc280e5eb615 # upstream 67a115e7a56dbdc3f5a58c64b29231151f3670f5 Patch1020: openssh-9.9p1-match-regression.patch +# upstream 6ce00f0c2ecbb9f75023dbe627ee6460bcec78c2 +# upstream 0832aac79517611dd4de93ad0a83577994d9c907 +Patch1021: openssh-9.9p2-error_processing.patch License: BSD-3-Clause AND BSD-2-Clause AND ISC AND SSH-OpenSSH AND ssh-keyscan AND sprintf AND LicenseRef-Fedora-Public-Domain AND X11-distribute-modifications-variant Requires: /sbin/nologin @@ -387,6 +390,7 @@ gpgv2 --quiet --keyring %{SOURCE3} %{SOURCE1} %{SOURCE0} %patch -P 1018 -p1 -b .openssl-log %patch -P 1019 -p1 -b .mlkembe %patch -P 1020 -p1 -b .match +%patch -P 1021 -p1 -b .errcode_set %patch -P 100 -p1 -b .coverity @@ -669,6 +673,11 @@ test -f %{sysconfig_anaconda} && \ * Thu Feb 13 2025 Dmitry Belyavskiy - 9.9p1-6 - Fix regression of Match directive processing Related: RHEL-76317 +- Fix missing error codes set and invalid error code checks in OpenSSH. It + prevents memory exhaustion attack and a MITM attack when VerifyHostKeyDNS + is on (CVE-2025-26465, CVE-2025-26466). + Resolves: RHEL-78699 + Resolves: RHEL-78943 * Mon Jan 27 2025 Dmitry Belyavskiy - 9.9p1-5 - Fix regression of Match directive processing