upstream: When doing the fork+exec'ing for ssh-keysign, rearrange

the socket into fd3, so as to not mistakenly leak other fd forward
accidentally. ok djm

OpenBSD-Commit-ID: 24cc753f5aa2c6a7d0fbf62766adbc75cd785296
This commit is contained in:
deraadt@openbsd.org 2019-05-15 04:43:31 +00:00 committed by Darren Tucker
parent db7606d4a6
commit a1d29cc36a
1 changed files with 9 additions and 7 deletions

View File

@ -1,4 +1,4 @@
/* $OpenBSD: sshconnect2.c,v 1.303 2019/02/12 23:53:10 djm Exp $ */ /* $OpenBSD: sshconnect2.c,v 1.304 2019/05/15 04:43:31 deraadt Exp $ */
/* /*
* Copyright (c) 2000 Markus Friedl. All rights reserved. * Copyright (c) 2000 Markus Friedl. All rights reserved.
* Copyright (c) 2008 Damien Miller. All rights reserved. * Copyright (c) 2008 Damien Miller. All rights reserved.
@ -1833,7 +1833,7 @@ ssh_keysign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp,
struct sshbuf *b; struct sshbuf *b;
struct stat st; struct stat st;
pid_t pid; pid_t pid;
int i, r, to[2], from[2], status; int r, to[2], from[2], status;
int sock = ssh_packet_get_connection_in(ssh); int sock = ssh_packet_get_connection_in(ssh);
u_char rversion = 0, version = 2; u_char rversion = 0, version = 2;
void (*osigchld)(int); void (*osigchld)(int);
@ -1863,8 +1863,6 @@ ssh_keysign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp,
} }
osigchld = signal(SIGCHLD, SIG_DFL); osigchld = signal(SIGCHLD, SIG_DFL);
if (pid == 0) { if (pid == 0) {
/* keep the socket on exec */
fcntl(sock, F_SETFD, 0);
close(from[0]); close(from[0]);
if (dup2(from[1], STDOUT_FILENO) < 0) if (dup2(from[1], STDOUT_FILENO) < 0)
fatal("%s: dup2: %s", __func__, strerror(errno)); fatal("%s: dup2: %s", __func__, strerror(errno));
@ -1873,10 +1871,13 @@ ssh_keysign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp,
fatal("%s: dup2: %s", __func__, strerror(errno)); fatal("%s: dup2: %s", __func__, strerror(errno));
close(from[1]); close(from[1]);
close(to[0]); close(to[0]);
/* Close everything but stdio and the socket */
for (i = STDERR_FILENO + 1; i < sock; i++) if (dup2(sock, STDERR_FILENO + 1) < 0)
close(i); fatal("%s: dup2: %s", __func__, strerror(errno));
sock = STDERR_FILENO + 1;
fcntl(sock, F_SETFD, 0); /* keep the socket on exec */
closefrom(sock + 1); closefrom(sock + 1);
debug3("%s: [child] pid=%ld, exec %s", debug3("%s: [child] pid=%ld, exec %s",
__func__, (long)getpid(), _PATH_SSH_KEY_SIGN); __func__, (long)getpid(), _PATH_SSH_KEY_SIGN);
execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL); execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL);
@ -1885,6 +1886,7 @@ ssh_keysign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp,
} }
close(from[1]); close(from[1]);
close(to[0]); close(to[0]);
sock = STDIN_FILENO + 1;
if ((b = sshbuf_new()) == NULL) if ((b = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__); fatal("%s: sshbuf_new failed", __func__);