- djm@cvs.openbsd.org 2011/06/22 21:57:01
[servconf.c servconf.h sshd.c sshd_config.5 sandbox-rlimit.c]
[sandbox-systrace.c sandbox.h configure.ac Makefile.in]
introduce sandboxing of the pre-auth privsep child using systrace(4).
This introduces a new "UsePrivilegeSeparation=sandbox" option for
sshd_config that applies mandatory restrictions on the syscalls the
privsep child can perform. This prevents a compromised privsep child
from being used to attack other hosts (by opening sockets and proxying)
or probing local kernel attack surface.
The sandbox is implemented using systrace(4) in unsupervised "fast-path"
mode, where a list of permitted syscalls is supplied. Any syscall not
on the list results in SIGKILL being sent to the privsep child. Note
that this requires a kernel with the new SYSTR_POLICY_KILL option.
UsePrivilegeSeparation=sandbox will become the default in the future
so please start testing it now.
feedback dtucker@; ok markus@
diff --git a/ChangeLog b/ChangeLog
index b8adb8a..6a18e71 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,6 +3,26 @@
- djm@cvs.openbsd.org 2011/06/22 21:47:28
[servconf.c]
reuse the multistate option arrays to pretty-print options for "sshd -T"
+ - djm@cvs.openbsd.org 2011/06/22 21:57:01
+ [servconf.c servconf.h sshd.c sshd_config.5]
+ [configure.ac Makefile.in]
+ introduce sandboxing of the pre-auth privsep child using systrace(4).
+
+ This introduces a new "UsePrivilegeSeparation=sandbox" option for
+ sshd_config that applies mandatory restrictions on the syscalls the
+ privsep child can perform. This prevents a compromised privsep child
+ from being used to attack other hosts (by opening sockets and proxying)
+ or probing local kernel attack surface.
+
+ The sandbox is implemented using systrace(4) in unsupervised "fast-path"
+ mode, where a list of permitted syscalls is supplied. Any syscall not
+ on the list results in SIGKILL being sent to the privsep child. Note
+ that this requires a kernel with the new SYSTR_POLICY_KILL option.
+
+ UsePrivilegeSeparation=sandbox will become the default in the future
+ so please start testing it now.
+
+ feedback dtucker@; ok markus@
20110620
- OpenBSD CVS Sync
diff --git a/Makefile.in b/Makefile.in
index f5b1476..f64aaac 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -1,4 +1,4 @@
-# $Id: Makefile.in,v 1.322 2011/05/05 03:48:37 djm Exp $
+# $Id: Makefile.in,v 1.323 2011/06/22 22:30:03 djm Exp $
# uncomment if you run a non bourne compatable shell. Ie. csh
#SHELL = @SH@
@@ -89,7 +89,8 @@
auth2-gss.o gss-serv.o gss-serv-krb5.o \
loginrec.o auth-pam.o auth-shadow.o auth-sia.o md5crypt.o \
sftp-server.o sftp-common.o \
- roaming_common.o roaming_serv.o
+ roaming_common.o roaming_serv.o \
+ sandbox-null.o sandbox-rlimit.o sandbox-systrace.o
MANPAGES = moduli.5.out scp.1.out ssh-add.1.out ssh-agent.1.out ssh-keygen.1.out ssh-keyscan.1.out ssh.1.out sshd.8.out sftp-server.8.out sftp.1.out ssh-keysign.8.out ssh-pkcs11-helper.8.out sshd_config.5.out ssh_config.5.out
MANPAGES_IN = moduli.5 scp.1 ssh-add.1 ssh-agent.1 ssh-keygen.1 ssh-keyscan.1 ssh.1 sshd.8 sftp-server.8 sftp.1 ssh-keysign.8 ssh-pkcs11-helper.8 sshd_config.5 ssh_config.5
diff --git a/configure.ac b/configure.ac
index 8f36338..380a8b9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,4 +1,4 @@
-# $Id: configure.ac,v 1.476 2011/06/03 02:11:38 djm Exp $
+# $Id: configure.ac,v 1.477 2011/06/22 22:30:03 djm Exp $
#
# Copyright (c) 1999-2004 Damien Miller
#
@@ -15,7 +15,7 @@
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
AC_INIT([OpenSSH], [Portable], [openssh-unix-dev@mindrot.org])
-AC_REVISION($Revision: 1.476 $)
+AC_REVISION($Revision: 1.477 $)
AC_CONFIG_SRCDIR([ssh.c])
AC_LANG([C])
@@ -106,6 +106,16 @@
AC_C_INLINE
AC_CHECK_DECL([LLONG_MAX], [have_llong_max=1], , [#include <limits.h>])
+AC_CHECK_DECL([SYSTR_POLICY_KILL], [have_systr_policy_kill=1], , [
+ #include <sys/types.h>
+ #include <sys/param.h>
+ #include <dev/systrace.h>
+])
+AC_CHECK_DECL([RLIMIT_NPROC],
+ [AC_DEFINE([HAVE_RLIMIT_NPROC], [], [sys/resource.h has RLIMIT_NPROC])], , [
+ #include <sys/types.h>
+ #include <sys/resource.h>
+])
use_stack_protector=1
AC_ARG_WITH([stackprotect],
@@ -2461,6 +2471,34 @@
[non-privileged user for privilege separation])
AC_SUBST([SSH_PRIVSEP_USER])
+# Decide which sandbox style to use
+sandbox_arg=""
+AC_ARG_WITH([sandbox],
+ [ --with-sandbox=style Specify privilege separation sandbox (no, rlimit, systrace)],
+ [
+ if test "x$withval" = "xyes" ; then
+ sandbox_arg=""
+ else
+ sandbox_arg="$withval"
+ fi
+ ]
+)
+if test "x$sandbox_arg" = "xsystrace" || \
+ ( test -z "$sandbox_arg" && test "x$have_systr_policy_kill" = "x1" ) ; then
+ SANDBOX_STYLE="systrace"
+ AC_DEFINE([SANDBOX_SYSTRACE], [1], [Sandbox using systrace(4)])
+elif test "x$sandbox_arg" = "xrlimit" || \
+ ( test -z "$sandbox_arg" && test "x$ac_cv_func_setrlimit" = "xyes" ) ; then
+ SANDBOX_STYLE="rlimit"
+ AC_DEFINE([SANDBOX_RLIMIT], [1], [Sandbox using setrlimit(2)])
+elif test -z "$sandbox_arg" || test "x$sandbox_arg" = "xno" || \
+ test "x$sandbox_arg" = "xnone" || test "x$sandbox_arg" = "xnull" ; then
+ SANDBOX_STYLE="none"
+ AC_DEFINE([SANDBOX_NULL], [1], [no privsep sandboxing])
+else
+ AC_MSG_ERROR([unsupported -with-sandbox])
+fi
+
# Cheap hack to ensure NEWS-OS libraries are arranged right.
if test ! -z "$SONY" ; then
LIBS="$LIBS -liberty";
@@ -4191,6 +4229,7 @@
echo " Translate v4 in v6 hack: $IPV4_IN6_HACK_MSG"
echo " BSD Auth support: $BSD_AUTH_MSG"
echo " Random number source: $RAND_MSG"
+echo " Privsep sandbox style: $SANDBOX_STYLE"
echo ""
diff --git a/sandbox-rlimit.c b/sandbox-rlimit.c
new file mode 100644
index 0000000..4d832fc
--- /dev/null
+++ b/sandbox-rlimit.c
@@ -0,0 +1,92 @@
+/*
+ * Copyright (c) 2011 Damien Miller <djm@mindrot.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "includes.h"
+
+#ifdef SANDBOX_RLIMIT
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+
+#include <errno.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "log.h"
+#include "sandbox.h"
+#include "xmalloc.h"
+
+/* Minimal sandbox that sets zero nfiles, nprocs and filesize rlimits */
+
+struct ssh_sandbox {
+ pid_t child_pid;
+};
+
+struct ssh_sandbox *
+ssh_sandbox_init(void)
+{
+ struct ssh_sandbox *box;
+
+ /*
+ * Strictly, we don't need to maintain any state here but we need
+ * to return non-NULL to satisfy the API.
+ */
+ debug3("%s: preparing rlimit sandbox", __func__);
+ box = xcalloc(1, sizeof(*box));
+ box->child_pid = 0;
+
+ return box;
+}
+
+void
+ssh_sandbox_child(struct ssh_sandbox *box)
+{
+ struct rlimit rl_zero;
+
+ rl_zero.rlim_cur = rl_zero.rlim_max = 0;
+
+ if (setrlimit(RLIMIT_FSIZE, &rl_zero) == -1)
+ fatal("%s: setrlimit(RLIMIT_FSIZE, { 0, 0 }): %s",
+ __func__, strerror(errno));
+ if (setrlimit(RLIMIT_NOFILE, &rl_zero) == -1)
+ fatal("%s: setrlimit(RLIMIT_NOFILE, { 0, 0 }): %s",
+ __func__, strerror(errno));
+#ifdef HAVE_RLIMIT_NPROC
+ if (setrlimit(RLIMIT_NPROC, &rl_zero) == -1)
+ fatal("%s: setrlimit(RLIMIT_NPROC, { 0, 0 }): %s",
+ __func__, strerror(errno));
+#endif
+}
+
+void
+ssh_sandbox_parent_finish(struct ssh_sandbox *box)
+{
+ free(box);
+ debug3("%s: finished", __func__);
+}
+
+void
+ssh_sandbox_parent_preauth(struct ssh_sandbox *box, pid_t child_pid)
+{
+ box->child_pid = child_pid;
+}
+
+#endif /* SANDBOX_RLIMIT */
diff --git a/sandbox-systrace.c b/sandbox-systrace.c
new file mode 100644
index 0000000..5d0b7fb
--- /dev/null
+++ b/sandbox-systrace.c
@@ -0,0 +1,187 @@
+/*
+ * Copyright (c) 2011 Damien Miller <djm@mindrot.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "includes.h"
+
+#ifdef SANDBOX_SYSTRACE
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/ioctl.h>
+#include <sys/syscall.h>
+#include <sys/socket.h>
+
+#include <dev/systrace.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "atomicio.h"
+#include "log.h"
+#include "sandbox.h"
+#include "xmalloc.h"
+
+static const int preauth_policy[] = {
+ SYS___sysctl,
+ SYS_close,
+ SYS_exit,
+ SYS_getpid,
+ SYS_gettimeofday,
+ SYS_madvise,
+ SYS_mmap,
+ SYS_mprotect,
+ SYS_poll,
+ SYS_munmap,
+ SYS_read,
+ SYS_select,
+ SYS_sigprocmask,
+ SYS_write,
+ -1
+};
+
+struct ssh_sandbox {
+ int child_sock;
+ int parent_sock;
+ int systrace_fd;
+ pid_t child_pid;
+ struct systrace_policy policy;
+};
+
+struct ssh_sandbox *
+ssh_sandbox_init(void)
+{
+ struct ssh_sandbox *box;
+ int s[2];
+
+ debug3("%s: preparing systrace sandbox", __func__);
+ box = xcalloc(1, sizeof(*box));
+ if (socketpair(AF_UNIX, SOCK_STREAM, 0, s) == -1)
+ fatal("%s: socketpair: %s", __func__, strerror(errno));
+ box->child_sock = s[0];
+ box->parent_sock = s[1];
+ box->systrace_fd = -1;
+ box->child_pid = 0;
+
+ return box;
+}
+
+void
+ssh_sandbox_child(struct ssh_sandbox *box)
+{
+ char whatever = 0;
+
+ close(box->parent_sock);
+ /* Signal parent that we are ready */
+ debug3("%s: ready", __func__);
+ if (atomicio(vwrite, box->child_sock, &whatever, 1) != 1)
+ fatal("%s: write: %s", __func__, strerror(errno));
+ /* Wait for parent to signal for us to go */
+ if (atomicio(read, box->child_sock, &whatever, 1) != 1)
+ fatal("%s: read: %s", __func__, strerror(errno));
+ debug3("%s: started", __func__);
+ close(box->child_sock);
+}
+
+static void
+ssh_sandbox_parent(struct ssh_sandbox *box, pid_t child_pid,
+ const int *allowed_syscalls)
+{
+ int dev_systrace, i, j, found;
+ char whatever = 0;
+
+ debug3("%s: wait for child %ld", __func__, (long)child_pid);
+ box->child_pid = child_pid;
+ close(box->child_sock);
+ /* Wait for child to signal that it is ready */
+ if (atomicio(read, box->parent_sock, &whatever, 1) != 1)
+ fatal("%s: read: %s", __func__, strerror(errno));
+ debug3("%s: child %ld ready", __func__, (long)child_pid);
+
+ /* Set up systracing of child */
+ if ((dev_systrace = open("/dev/systrace", O_RDONLY)) == -1)
+ fatal("%s: open(\"/dev/systrace\"): %s", __func__,
+ strerror(errno));
+ if (ioctl(dev_systrace, STRIOCCLONE, &box->systrace_fd) == -1)
+ fatal("%s: ioctl(STRIOCCLONE, %d): %s", __func__,
+ dev_systrace, strerror(errno));
+ close(dev_systrace);
+ debug3("%s: systrace attach, fd=%d", __func__, box->systrace_fd);
+ if (ioctl(box->systrace_fd, STRIOCATTACH, &child_pid) == -1)
+ fatal("%s: ioctl(%d, STRIOCATTACH, %d): %s", __func__,
+ box->systrace_fd, child_pid, strerror(errno));
+
+ /* Allocate and assign policy */
+ bzero(&box->policy, sizeof(box->policy));
+ box->policy.strp_op = SYSTR_POLICY_NEW;
+ box->policy.strp_maxents = SYS_MAXSYSCALL;
+ if (ioctl(box->systrace_fd, STRIOCPOLICY, &box->policy) == -1)
+ fatal("%s: ioctl(%d, STRIOCPOLICY (new)): %s", __func__,
+ box->systrace_fd, strerror(errno));
+
+ box->policy.strp_op = SYSTR_POLICY_ASSIGN;
+ box->policy.strp_pid = box->child_pid;
+ if (ioctl(box->systrace_fd, STRIOCPOLICY, &box->policy) == -1)
+ fatal("%s: ioctl(%d, STRIOCPOLICY (assign)): %s",
+ __func__, box->systrace_fd, strerror(errno));
+
+ /* Set per-syscall policy */
+ for (i = 0; i < SYS_MAXSYSCALL; i++) {
+ for (j = found = 0; allowed_syscalls[j] != -1 && !found; j++) {
+ if (allowed_syscalls[j] == i)
+ found = 1;
+ }
+ box->policy.strp_op = SYSTR_POLICY_MODIFY;
+ box->policy.strp_code = i;
+ box->policy.strp_policy = found ?
+ SYSTR_POLICY_PERMIT : SYSTR_POLICY_KILL;
+ if (found)
+ debug3("%s: policy: enable syscall %d", __func__, i);
+ if (ioctl(box->systrace_fd, STRIOCPOLICY,
+ &box->policy) == -1)
+ fatal("%s: ioctl(%d, STRIOCPOLICY (modify)): %s",
+ __func__, box->systrace_fd, strerror(errno));
+ }
+
+ /* Signal the child to start running */
+ debug3("%s: start child %ld", __func__, (long)child_pid);
+ if (atomicio(vwrite, box->parent_sock, &whatever, 1) != 1)
+ fatal("%s: write: %s", __func__, strerror(errno));
+ close(box->parent_sock);
+}
+
+void
+ssh_sandbox_parent_finish(struct ssh_sandbox *box)
+{
+ /* Closing this before the child exits will terminate it */
+ close(box->systrace_fd);
+
+ free(box);
+ debug3("%s: finished", __func__);
+}
+
+void
+ssh_sandbox_parent_preauth(struct ssh_sandbox *box, pid_t child_pid)
+{
+ ssh_sandbox_parent(box, child_pid, preauth_policy);
+}
+
+#endif /* SANDBOX_SYSTRACE */
diff --git a/sandbox.h b/sandbox.h
new file mode 100755
index 0000000..5fe3064
--- /dev/null
+++ b/sandbox.h
@@ -0,0 +1,23 @@
+/* $OpenBSD: sandbox.h,v 1.2 2011/06/22 22:14:05 djm Exp $ */
+/*
+ * Copyright (c) 2011 Damien Miller <djm@mindrot.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+struct ssh_sandbox;
+
+struct ssh_sandbox *ssh_sandbox_init(void);
+void ssh_sandbox_child(struct ssh_sandbox *);
+void ssh_sandbox_parent_finish(struct ssh_sandbox *);
+void ssh_sandbox_parent_preauth(struct ssh_sandbox *, pid_t);
diff --git a/servconf.c b/servconf.c
index 03b9746..91986e5 100644
--- a/servconf.c
+++ b/servconf.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: servconf.c,v 1.221 2011/06/22 21:47:28 djm Exp $ */
+/* $OpenBSD: servconf.c,v 1.222 2011/06/22 21:57:01 djm Exp $ */
/*
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
@@ -280,7 +280,7 @@
/* Turn privilege separation on by default */
if (use_privsep == -1)
- use_privsep = 1;
+ use_privsep = PRIVSEP_ON;
#ifndef HAVE_MMAP
if (use_privsep && options->compression == 1) {
@@ -701,6 +701,12 @@
{ "no", 0 },
{ NULL, -1 }
};
+static const struct multistate multistate_privsep[] = {
+ { "sandbox", PRIVSEP_SANDBOX },
+ { "yes", PRIVSEP_ON },
+ { "no", PRIVSEP_OFF },
+ { NULL, -1 }
+};
int
process_server_config_line(ServerOptions *options, char *line,
@@ -1066,7 +1072,8 @@
case sUsePrivilegeSeparation:
intptr = &use_privsep;
- goto parse_flag;
+ multistate_ptr = multistate_privsep;
+ goto parse_multistate;
case sAllowUsers:
while ((arg = strdelim(&cp)) && *arg != '\0') {
@@ -1574,6 +1581,8 @@
return fmt_multistate_int(val, multistate_gatewayports);
case sCompression:
return fmt_multistate_int(val, multistate_compression);
+ case sUsePrivilegeSeparation:
+ return fmt_multistate_int(val, multistate_privsep);
case sProtocol:
switch (val) {
case SSH_PROTO_1:
diff --git a/servconf.h b/servconf.h
index 31e621b..89f38e2 100644
--- a/servconf.h
+++ b/servconf.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: servconf.h,v 1.98 2011/05/23 03:30:07 djm Exp $ */
+/* $OpenBSD: servconf.h,v 1.99 2011/06/22 21:57:01 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -36,6 +36,11 @@
#define PERMIT_NO_PASSWD 2
#define PERMIT_YES 3
+/* use_privsep */
+#define PRIVSEP_OFF 0
+#define PRIVSEP_ON 1
+#define PRIVSEP_SANDBOX 2
+
#define DEFAULT_AUTH_FAIL_MAX 6 /* Default for MaxAuthTries */
#define DEFAULT_SESSIONS_MAX 10 /* Default for MaxSessions */
diff --git a/sshd.c b/sshd.c
index 6e15522..bebcb9b 100644
--- a/sshd.c
+++ b/sshd.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshd.c,v 1.383 2011/06/17 21:44:31 djm Exp $ */
+/* $OpenBSD: sshd.c,v 1.384 2011/06/22 21:57:01 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -118,6 +118,7 @@
#endif
#include "monitor_wrap.h"
#include "roaming.h"
+#include "sandbox.h"
#include "version.h"
#ifdef LIBWRAP
@@ -624,18 +625,23 @@
{
int status;
pid_t pid;
+ struct ssh_sandbox *box = NULL;
/* Set up unprivileged child process to deal with network data */
pmonitor = monitor_init();
/* Store a pointer to the kex for later rekeying */
pmonitor->m_pkex = &xxx_kex;
+ if (use_privsep == PRIVSEP_SANDBOX)
+ box = ssh_sandbox_init();
pid = fork();
if (pid == -1) {
fatal("fork of unprivileged child failed");
} else if (pid != 0) {
debug2("Network child is on pid %ld", (long)pid);
+ if (box != NULL)
+ ssh_sandbox_parent_preauth(box, pid);
pmonitor->m_pid = pid;
monitor_child_preauth(authctxt, pmonitor);
@@ -643,10 +649,21 @@
monitor_sync(pmonitor);
/* Wait for the child's exit status */
- while (waitpid(pid, &status, 0) < 0)
+ while (waitpid(pid, &status, 0) < 0) {
if (errno != EINTR)
- break;
- return (1);
+ fatal("%s: waitpid: %s", __func__,
+ strerror(errno));
+ }
+ if (WIFEXITED(status)) {
+ if (WEXITSTATUS(status) != 0)
+ fatal("%s: preauth child exited with status %d",
+ __func__, WEXITSTATUS(status));
+ } else if (WIFSIGNALED(status))
+ fatal("%s: preauth child terminated by signal %d",
+ __func__, WTERMSIG(status));
+ if (box != NULL)
+ ssh_sandbox_parent_finish(box);
+ return 1;
} else {
/* child */
close(pmonitor->m_sendfd);
@@ -659,8 +676,11 @@
if (getuid() == 0 || geteuid() == 0)
privsep_preauth_child();
setproctitle("%s", "[net]");
+ if (box != NULL)
+ ssh_sandbox_child(box);
+
+ return 0;
}
- return (0);
}
static void
diff --git a/sshd_config.5 b/sshd_config.5
index 70a53b3..f78452c 100644
--- a/sshd_config.5
+++ b/sshd_config.5
@@ -33,8 +33,8 @@
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
-.\" $OpenBSD: sshd_config.5,v 1.133 2011/05/23 07:10:21 jmc Exp $
-.Dd $Mdocdate: May 23 2011 $
+.\" $OpenBSD: sshd_config.5,v 1.134 2011/06/22 21:57:01 djm Exp $
+.Dd $Mdocdate: June 22 2011 $
.Dt SSHD_CONFIG 5
.Os
.Sh NAME
@@ -1071,6 +1071,12 @@
escalation by containing any corruption within the unprivileged processes.
The default is
.Dq yes .
+If
+.Cm UsePrivilegeSeparation
+is set to
+.Dq sandbox
+then the pre-authentication unprivileged process is subject to additional
+restrictions.
.It Cm X11DisplayOffset
Specifies the first display number available for
.Xr sshd 8 Ns 's