-https://bugzilla.mindrot.org/show_bug.cgi?id=2142
-
---- a/Makefile.in
-+++ a/Makefile.in
-@@ -112,7 +112,7 @@ SSHDOBJS=sshd.o auth-rhosts.o auth-passw
- loginrec.o auth-pam.o auth-shadow.o auth-sia.o md5crypt.o \
- sftp-server.o sftp-common.o \
- sandbox-null.o sandbox-rlimit.o sandbox-systrace.o sandbox-darwin.o \
-- sandbox-seccomp-filter.o sandbox-capsicum.o sandbox-pledge.o \
-+ sandbox-seccomp-filter.o sandbox-libseccomp-filter.o sandbox-capsicum.o sandbox-pledge.o \
- sandbox-solaris.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 ssh-ldap-helper.8.out sshd_config.5.out ssh_config.5.out ssh-ldap.conf.5.out
---- a/configure.ac
-+++ a/configure.ac
-@@ -2867,11 +2867,22 @@ else
- fi
- AC_SUBST([SSH_PRIVSEP_USER])
-
-+AC_CHECK_DECL([SCMP_ARCH_NATIVE], [have_libseccomp_filter=1], , [
-+ #include <sys/types.h>
-+ #include <seccomp.h>
-+])
-+if test "x$have_libseccomp_filter" = "x1" ; then
-+ AC_CHECK_LIB([seccomp], [seccomp_init],
-+ [LIBS="$LIBS -lseccomp"],
-+ [have_libseccomp_filter=0])
-+fi
-+
- if test "x$have_linux_no_new_privs" = "x1" ; then
- AC_CHECK_DECL([SECCOMP_MODE_FILTER], [have_seccomp_filter=1], , [
- #include <sys/types.h>
- #include <linux/seccomp.h>
- ])
-+
- fi
- if test "x$have_seccomp_filter" = "x1" ; then
- AC_MSG_CHECKING([kernel for seccomp_filter support])
-@@ -2898,7 +2909,7 @@ fi
- # Decide which sandbox style to use
- sandbox_arg=""
- AC_ARG_WITH([sandbox],
-- [ --with-sandbox=style Specify privilege separation sandbox (no, capsicum, darwin, rlimit, seccomp_filter, systrace, pledge)],
-+ [ --with-sandbox=style Specify privilege separation sandbox (no, capsicum, darwin, rlimit, seccomp_filter, libseccomp_filter, systrace, pledge)],
- [
- if test "x$withval" = "xyes" ; then
- sandbox_arg=""
-@@ -3008,6 +3019,13 @@ elif test "x$sandbox_arg" = "xdarwin" || \
- AC_MSG_ERROR([Darwin seatbelt sandbox requires sandbox.h and sandbox_init function])
- SANDBOX_STYLE="darwin"
- AC_DEFINE([SANDBOX_DARWIN], [1], [Sandbox using Darwin sandbox_init(3)])
-+elif test "x$sandbox_arg" = "xlibseccomp_filter" || \
-+ ( test -z "$sandbox_arg" && \
-+ test "x$have_libseccomp_filter" = "x1" ) ; then
-+ test "x$have_libseccomp_filter" != "x1" && \
-+ AC_MSG_ERROR([libseccomp_filter sandbox not supported on $host])
-+ SANDBOX_STYLE="libseccomp_filter"
-+ AC_DEFINE([SANDBOX_LIBSECCOMP_FILTER], [1], [Sandbox using libseccomp filter])
- elif test "x$sandbox_arg" = "xseccomp_filter" || \
- ( test -z "$sandbox_arg" && \
- test "x$have_seccomp_filter" = "x1" && \
---- a/sandbox-libseccomp-filter.c
-+++ a/sandbox-libseccomp-filter.c
-@@ -0,0 +1,175 @@
-+/*
-+ * Copyright (c) 2012 Will Drewry <wad@dataspill.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_LIBSECCOMP_FILTER
-+
-+#include <sys/types.h>
-+#include <sys/resource.h>
-+#include <seccomp.h>
-+
-+#include <errno.h>
-+#include <signal.h>
-+#include <stdarg.h>
-+#include <stddef.h> /* for offsetof */
-+#include <stdio.h>
-+#include <stdlib.h>
-+#include <string.h>
-+#include <unistd.h>
-+
-+#include "log.h"
-+#include "ssh-sandbox.h"
-+#include "xmalloc.h"
-+
-+struct ssh_sandbox {
-+ pid_t child_pid;
-+};
-+
-+struct ssh_sandbox *
-+ssh_sandbox_init(struct monitor *monitor)
-+{
-+ 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 libseccomp filter sandbox", __func__);
-+ box = xcalloc(1, sizeof(*box));
-+ box->child_pid = 0;
-+
-+ return box;
-+}
-+
-+static int
-+seccomp_add_secondary_archs(scmp_filter_ctx *c)
-+{
-+#if defined(__i386__) || defined(__x86_64__)
-+ int r;
-+ r = seccomp_arch_add(c, SCMP_ARCH_X86);
-+ if (r < 0 && r != -EEXIST)
-+ return r;
-+ r = seccomp_arch_add(c, SCMP_ARCH_X86_64);
-+ if (r < 0 && r != -EEXIST)
-+ return r;
-+ r = seccomp_arch_add(c, SCMP_ARCH_X32);
-+ if (r < 0 && r != -EEXIST)
-+ return r;
-+#endif
-+ return 0;
-+}
-+
-+struct scmp_action_def {
-+ uint32_t action;
-+ int syscall;
-+};
-+
-+static const struct scmp_action_def preauth_insns[] = {
-+ {SCMP_ACT_ERRNO(EACCES), SCMP_SYS(open)},
-+ {SCMP_ACT_ERRNO(EACCES), SCMP_SYS(stat)},
-+ {SCMP_ACT_ALLOW, SCMP_SYS(getpid)},
-+ {SCMP_ACT_ALLOW, SCMP_SYS(getpid)},
-+ {SCMP_ACT_ALLOW, SCMP_SYS(gettimeofday)},
-+ {SCMP_ACT_ALLOW, SCMP_SYS(clock_gettime)},
-+#ifdef __NR_time /* not defined on EABI ARM */
-+ {SCMP_ACT_ALLOW, SCMP_SYS(time)},
-+#endif
-+ {SCMP_ACT_ALLOW, SCMP_SYS(read)},
-+ {SCMP_ACT_ALLOW, SCMP_SYS(write)},
-+ {SCMP_ACT_ALLOW, SCMP_SYS(close)},
-+#ifdef __NR_shutdown /* not defined on archs that go via socketcall(2) */
-+ {SCMP_ACT_ALLOW, SCMP_SYS(shutdown)},
-+#endif
-+ {SCMP_ACT_ALLOW, SCMP_SYS(brk)},
-+ {SCMP_ACT_ALLOW, SCMP_SYS(poll)},
-+#ifdef __NR__newselect
-+ {SCMP_ACT_ALLOW, SCMP_SYS(_newselect)},
-+#endif
-+ {SCMP_ACT_ALLOW, SCMP_SYS(select)},
-+ {SCMP_ACT_ALLOW, SCMP_SYS(madvise)},
-+#ifdef __NR_mmap2 /* EABI ARM only has mmap2() */
-+ {SCMP_ACT_ALLOW, SCMP_SYS(mmap2)},
-+#endif
-+#ifdef __NR_mmap
-+ {SCMP_ACT_ALLOW, SCMP_SYS(mmap)},
-+#endif
-+#ifdef __dietlibc__
-+ {SCMP_ACT_ALLOW, SCMP_SYS(mremap)},
-+ {SCMP_ACT_ALLOW, SCMP_SYS(exit)},
-+#endif
-+ {SCMP_ACT_ALLOW, SCMP_SYS(munmap)},
-+ {SCMP_ACT_ALLOW, SCMP_SYS(exit_group)},
-+#ifdef __NR_rt_sigprocmask
-+ {SCMP_ACT_ALLOW, SCMP_SYS(rt_sigprocmask)},
-+#else
-+ {SCMP_ACT_ALLOW, SCMP_SYS(sigprocmask)},
-+#endif
-+ {0, 0}
-+};
-+
-+
-+void
-+ssh_sandbox_child(struct ssh_sandbox *box)
-+{
-+ scmp_filter_ctx *seccomp;
-+ struct rlimit rl_zero;
-+ const struct scmp_action_def *insn;
-+ int r;
-+
-+ /* Set rlimits for completeness if possible. */
-+ 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));
-+ if (setrlimit(RLIMIT_NPROC, &rl_zero) == -1)
-+ fatal("%s: setrlimit(RLIMIT_NPROC, { 0, 0 }): %s",
-+ __func__, strerror(errno));
-+
-+ seccomp = seccomp_init(SCMP_ACT_KILL);
-+ if (!seccomp)
-+ fatal("%s:libseccomp activation failed", __func__);
-+ if (seccomp_add_secondary_archs(seccomp))
-+ fatal("%s:libseccomp secondary arch setup failed", __func__);
-+
-+ for (insn = preauth_insns; insn->action; insn++) {
-+ if (seccomp_rule_add(seccomp, insn->action, insn->syscall, 0) < 0)
-+ fatal("%s:libseccomp rule failed", __func__);
-+ }
-+
-+ if ((r = seccomp_load(seccomp)) < 0)
-+ fatal("%s:libseccomp unable to load filter %d", __func__, r);
-+
-+ seccomp_release(seccomp);
-+}
-+
-+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_LIBSECCOMP_FILTER */
projects / packages / openssh.git / commitdiff