This release fixes a number of security bugs and has minor new features and bug fixes. Security fixes, from the release notes (https://www.openssh.com/txt/release-9.3): This release contains fixes for a security problem and a memory safety problem. The memory safety problem is not believed to be exploitable, but we report most network-reachable memory faults as security bugs. * ssh-add(1): when adding smartcard keys to ssh-agent(1) with the per-hop destination constraints (ssh-add -h ...) added in OpenSSH 8.9, a logic error prevented the constraints from being communicated to the agent. This resulted in the keys being added without constraints. The common cases of non-smartcard keys and keys without destination constraints are unaffected. This problem was reported by Luci Stanescu. * ssh(1): Portable OpenSSH provides an implementation of the getrrsetbyname(3) function if the standard library does not provide it, for use by the VerifyHostKeyDNS feature. A specifically crafted DNS response could cause this function to perform an out-of-bounds read of adjacent stack data, but this condition does not appear to be exploitable beyond denial-of- service to the ssh(1) client. The getrrsetbyname(3) replacement is only included if the system's standard library lacks this function and portable OpenSSH was not compiled with the ldns library (--with-ldns). getrrsetbyname(3) is only invoked if using VerifyHostKeyDNS to fetch SSHFP records. This problem was found by the Coverity static analyzer. Sponsored by: The FreeBSD Foundation
135 lines
3.5 KiB
C
135 lines
3.5 KiB
C
/* $OpenBSD: dispatch.c,v 1.33 2023/03/05 05:34:09 dtucker Exp $ */
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/*
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* Copyright (c) 2000 Markus Friedl. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "includes.h"
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#include <sys/types.h>
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#include <signal.h>
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#include <stdarg.h>
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#include "ssh2.h"
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#include "log.h"
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#include "dispatch.h"
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#include "packet.h"
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#include "ssherr.h"
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int
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dispatch_protocol_error(int type, u_int32_t seq, struct ssh *ssh)
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{
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int r;
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logit("dispatch_protocol_error: type %d seq %u", type, seq);
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if ((r = sshpkt_start(ssh, SSH2_MSG_UNIMPLEMENTED)) != 0 ||
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(r = sshpkt_put_u32(ssh, seq)) != 0 ||
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(r = sshpkt_send(ssh)) != 0 ||
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(r = ssh_packet_write_wait(ssh)) != 0)
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sshpkt_fatal(ssh, r, "%s", __func__);
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return 0;
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}
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int
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dispatch_protocol_ignore(int type, u_int32_t seq, struct ssh *ssh)
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{
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logit("dispatch_protocol_ignore: type %d seq %u", type, seq);
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return 0;
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}
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void
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ssh_dispatch_init(struct ssh *ssh, dispatch_fn *dflt)
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{
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u_int i;
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for (i = 0; i < DISPATCH_MAX; i++)
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ssh->dispatch[i] = dflt;
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}
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void
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ssh_dispatch_range(struct ssh *ssh, u_int from, u_int to, dispatch_fn *fn)
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{
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u_int i;
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for (i = from; i <= to; i++) {
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if (i >= DISPATCH_MAX)
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break;
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ssh->dispatch[i] = fn;
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}
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}
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void
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ssh_dispatch_set(struct ssh *ssh, int type, dispatch_fn *fn)
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{
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ssh->dispatch[type] = fn;
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}
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int
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ssh_dispatch_run(struct ssh *ssh, int mode, volatile sig_atomic_t *done)
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{
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int r;
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u_char type;
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u_int32_t seqnr;
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for (;;) {
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if (mode == DISPATCH_BLOCK) {
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r = ssh_packet_read_seqnr(ssh, &type, &seqnr);
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if (r != 0)
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return r;
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} else {
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r = ssh_packet_read_poll_seqnr(ssh, &type, &seqnr);
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if (r != 0)
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return r;
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if (type == SSH_MSG_NONE)
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return 0;
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}
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if (type > 0 && type < DISPATCH_MAX &&
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ssh->dispatch[type] != NULL) {
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if (ssh->dispatch_skip_packets) {
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debug2("skipped packet (type %u)", type);
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ssh->dispatch_skip_packets--;
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continue;
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}
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r = (*ssh->dispatch[type])(type, seqnr, ssh);
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if (r != 0)
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return r;
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} else {
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r = sshpkt_disconnect(ssh,
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"protocol error: rcvd type %d", type);
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if (r != 0)
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return r;
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return SSH_ERR_DISCONNECTED;
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}
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if (done != NULL && *done)
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return 0;
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}
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}
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void
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ssh_dispatch_run_fatal(struct ssh *ssh, int mode, volatile sig_atomic_t *done)
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{
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int r;
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if ((r = ssh_dispatch_run(ssh, mode, done)) != 0)
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sshpkt_fatal(ssh, r, "%s", __func__);
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}
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