This can set no_new_privs, uid, gid, groups, securebits, inheritable caps, the cap bounding set, securebits, and selinux and apparmor labels. Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx> --- For now, this still uses stdbool. I can change that. I also removed priverr completely. Changes from v1: - Check for libcap-ng in configure - Use err, errx, etc. as appropriate - Use strtol_or_err - Rename struct options to struct privctx and move it to the top - Improve behavior if new capabilities are added to the kernel - Fix some option parsing breakage (I used 256 twice) - Use CHAR_MAX+1 instead of 256 - Remove silly arrays for reuid and regid - Exit with code 1 instead of 127 if execve fails - Accept --no-new-privs - Improve man page Known issues: - There's no period after runcon(1) in setpriv.1. Anyone know how to add one? - The return codes are still 1 for general errors (including execve failure) and 127 for failures to set privileges. Is this okay? .gitignore | 1 + configure.ac | 16 + sys-utils/Makemodule.am | 7 + sys-utils/setpriv.1 | 135 +++++++++ sys-utils/setpriv.c | 778 ++++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 937 insertions(+) create mode 100644 sys-utils/setpriv.1 create mode 100644 sys-utils/setpriv.c diff --git a/.gitignore b/.gitignore index e85eb07..b3ed077 100644 --- a/.gitignore +++ b/.gitignore @@ -146,6 +146,7 @@ tests/run.sh.trs /script /scriptreplay /setarch +/setpriv /setsid /setterm /sfdisk diff --git a/configure.ac b/configure.ac index 727113a..17f4f0c 100644 --- a/configure.ac +++ b/configure.ac @@ -866,6 +866,22 @@ if test "x$build_unshare" = xyes; then fi +dnl +dnl setpriv depends on libcap-ng. It would be possible to build +dnl a version of setpriv with limited functionality without libcap-ng, +dnl but this isn't currently supported. +dnl +UL_CHECK_LIB([cap-ng], [capng_apply], [cap_ng]) +AC_ARG_ENABLE([setpriv], + AS_HELP_STRING([--disable-setpriv], [do not build setpriv]), + [], enable_setpriv=check +) +UL_BUILD_INIT([setpriv]) +UL_REQUIRES_LINUX([setpriv]) +UL_REQUIRES_HAVE([setpriv], [cap_ng], [libcap-ng]) +AM_CONDITIONAL(BUILD_SETPRIV, test "x$build_setpriv" = xyes) + + AC_ARG_ENABLE([arch], AS_HELP_STRING([--enable-arch], [do build arch]), [], enable_arch=no diff --git a/sys-utils/Makemodule.am b/sys-utils/Makemodule.am index c7b1eb3..1e8adc7 100644 --- a/sys-utils/Makemodule.am +++ b/sys-utils/Makemodule.am @@ -309,3 +309,10 @@ if HAVE_AUDIT hwclock_LDADD += -laudit endif endif # BUILD_HWCLOCK + +if BUILD_SETPRIV +usrbin_exec_PROGRAMS += setpriv +dist_man_MANS += sys-utils/setpriv.1 +setpriv_SOURCES = sys-utils/setpriv.c +setpriv_LDADD = $(LDADD) -lcap-ng libcommon.la +endif diff --git a/sys-utils/setpriv.1 b/sys-utils/setpriv.1 new file mode 100644 index 0000000..94227d3 --- /dev/null +++ b/sys-utils/setpriv.1 @@ -0,0 +1,135 @@ +.\" Process this file with +.\" groff -man -Tascii no_new_privs.1 +.\" +.TH SETPRIV 1 "December 2012" "util-linux" "User Commands" +.SH NAME +setpriv \- run program with different Linux privilege settings +.SH SYNOPSIS +.B setpriv +.RI [ options ] +program +.RI [ arguments ] +.SH DESCRIPTION +Sets or queries various Linux privilege settings that are inherited across +.BR execve (2) +. +.SH OPTION + +.TP +.BR \-d,\ --dump +Dumps current privilege state. Specify more than once to show extra, mostly useless, +information. Incompatible with all other options. + +.TP +.BR \--nnp,\ --no-new-privs +Sets the \fIno_new_privs\fP bit. With this bit set, +.BR execve (2) +will not grant new privileges. For example, the setuid and setgid bits as +well as file capabilities will be disabled. (Executing binaries with these +bits set will still work, but they will not gain privilege. Certain LSMs, +especially AppArmor, may result in failures to execute certain programs.) +This bit is inherited by child processes and cannot be unset. See +.BR prctl (2) +and +.IR Documentation/prctl/no_new_privs.txt +in the Linux kernel source. + +The no_new_privs bit is supported since Linux 3.5. + +.TP +.BR \--inh-caps=(+|-)cap,...\ or\ --bounding-set=(+|-)cap,... +Sets inheritable capabilities or capability bounding set. See +.BR capabilities (7). +The argument is a comma-separated list of +cap and -cap entries, +which add or remove an entry respectively. +all and -all can be used +to add or remove all caps. The set of capabilities starts out as +the current inheritable set for --inh-caps and the current bounding set +for --bounding-set. If you drop something from the bounding set +without also dropping it from the inheritable set, you are likely +to become confused. Don't do that. + +.TP +.BR \--list-caps +Lists all known capabilities. Must be specified alone. + +.TP +.BR \--ruid,\ --euid,\ --reuid +Sets the real, effective, or both UIDs. + +Setting uid or gid does not change capabilities, although the exec +call at the end might change capabilities. This means that, if you +are root, you probably want to do something like: + +--reuid=1000 --regid=1000 --caps=-all + +.TP +.BR \--rgid,\ --egid,\ --regid +Sets the real, effective, or both GIDs. + +For safety, you must specify one of --keep-groups, --clear-groups, or --groups if you +set any primary GID. + +.TP +.BR \--clear-groups +Clears supplementary groups. + +.TP +.BR \--keep-groups +Preserves supplementary groups. Only useful in conjunction with --rgid, --egid, +or --regid. + +.TP +.BR \--groups=group,... +Sets supplementary groups. + +.TP +.BR \--securebits=(+|-)securebit,... +Sets or clears securebits. The valid securebits are \fInoroot\fP, \fInoroot_locked\fP, +\fIno_setuid_fixup\fP, \fIno_setuid_fixup_locked\fP, and \fIkeep_caps_locked\fP. +\fIkeep_caps\fP is cleared by +.BR execve (2) +and is therefore not allowed. + +.TP +.BR \--selinux-label +Requests a particular SELinux transition (using a transition on exec, not dyntrans). +This will fail and cause +.BR setpriv (1) +to abort if SELinux is not in use, and the transition may be ignored or cause +.BR execve (2) +to fail at SELinux's whim. (In particular, this is unlikely to work in conjunction +with \fIno_new_privs\fP.) + +This is similar to +.BR runcon (1) + +.TP +.BR \--apparmor-profile +Requests a particular AppArmor profile (using a transition on exec). +This will fail and cause +.BR setpriv (1) +to abort if AppArmor is not in use, and the transition may be ignored or cause +.BR execve (2) +to fail at AppArmor's whim. + +.TP +.BR \-h , " \-\-help" +Print a help message, +.SH NOTES +If applying any specified option fails, \fIprogram\fP will not be run and +\fIsetpriv\fP will return with exit code 127. + +Be careful with this tool -- it may have unexpected security consequences. +For example, setting no_new_privs and then execing a program that is +SELinux-confined (as this tool would do) may prevent the SELinux +restrictions from taking effect. +.SH SEE ALSO +.BR prctl (2) +.BR capability (7) +.SH BUS +None known so far. +.SH AUTHOR +Andy Lutomirski <luto@xxxxxxxxxxxxxx> +.SH AVAILABILITY +The \fIsetpriv\fP command is part of the util-linux package and is available from +ftp://ftp.kernel.org/pub/linux/utils/util-linux/. diff --git a/sys-utils/setpriv.c b/sys-utils/setpriv.c new file mode 100644 index 0000000..d1f04f2 --- /dev/null +++ b/sys-utils/setpriv.c @@ -0,0 +1,778 @@ +/* + * setpriv(1) - set various kernel privilege bits and run something + * + * Copyright (C) 2012 Andy Lutomirski <luto@xxxxxxxxxxxxxx> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2, or (at your option) any + * later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include <errno.h> +#include <getopt.h> +#include <stdio.h> +#include <stdlib.h> +#include <stdbool.h> +#include <unistd.h> +#include <sys/prctl.h> +#include <linux/securebits.h> +#include <grp.h> +#include <stdarg.h> +#include <cap-ng.h> +#include "strutils.h" + +#include "nls.h" +#include "c.h" +#include "closestream.h" + +#ifndef PR_SET_NO_NEW_PRIVS +# define PR_SET_NO_NEW_PRIVS 38 +#endif +#ifndef PR_GET_NO_NEW_PRIVS +# define PR_GET_NO_NEW_PRIVS 39 +#endif + +#define SETPRIV_EXIT_PRIVERR 127 /* how we exit when we fail to set privs */ + +/* + * Note: we are subject to https://bugzilla.redhat.com/show_bug.cgi?id=895105 + * and we will therefore have problems if new capabilities are added. + * Once that bug is fixed, I'll submit a corresponding fix to setpriv. In + * the mean time, the code here tries to work reasonably well. + */ + +struct privctx { + bool nnp; + + /* real and effective (in that order) */ + bool have_ruid, have_euid, have_rgid, have_egid; + uid_t ruid, euid; + gid_t rgid, egid; + + /* supplementary groups */ + bool have_groups, keep_groups, clear_groups; + size_t num_groups; + gid_t *groups; + + /* caps */ + const char *caps_to_inherit; + const char *bounding_set; + + /* securebits */ + bool have_securebits; + int securebits; + + /* LSMs */ + const char *selinux_label; + const char *apparmor_profile; +}; + +static void usage(int status) +{ + FILE *out = status == EXIT_SUCCESS ? stdout : stderr; + + fputs(USAGE_HEADER, out); + fprintf(out, + _(" %s [options] <program> [args...]\n"), program_invocation_short_name); + fputs(_(" -d, --dump show current state (and don't exec anything)\n" + " --nnp, --no-new-privs set no_new_privs\n" + " --inh-caps=caps set inheritable capabilities\n" + " --bounding-set=caps set capability bounding set\n" + " --ruid, --euid set real or effective uid respectively\n" + " --rgid, --egid set real or effective gid respectively\n" + " --reuid, --regid set real and effective uid or gid\n" + " --clear-groups clear supplementary groups\n" + " --keep-groups keep supplementary groups\n" + " --groups=group,... set supplementary groups\n" + " --securebits=bits set securebits\n" + " --selinux-label set SELinux label (requires process:transition)\n" + " --apparmor-profile set AppArmor profile (requires onexec permission)\n" + "\n" + " This tool can be dangerous. Be careful and read the manpage."), out); + + fputs(USAGE_SEPARATOR, out); + fputs(USAGE_HELP, out); + fputs(USAGE_VERSION, out); + fprintf(out, USAGE_MAN_TAIL("setpriv(1)")); + + exit(status); +} + +static int real_cap_last_cap(void) +{ + /* CAP_LAST_CAP is untrustworthy. */ + + static int ret = -1; + int matched; + + if (ret != -1) + return ret; + + FILE *f = fopen("/proc/sys/kernel/cap_last_cap", "r"); + if (!f) { + ret = CAP_LAST_CAP; /* guess */ + return ret; + } + + matched = fscanf(f, "%d", &ret); + fclose(f); + + if (matched != 1) + ret = CAP_LAST_CAP; /* guess */ + + return ret; +} + +/* Returns the number of capabilities printed. */ +static int print_caps(FILE *f, capng_type_t which) +{ + int n = 0; + for (int i = 0; i <= real_cap_last_cap(); i++) { + if (capng_have_capability(which, i)) { + const char *name = capng_capability_to_name(i); + if (n) + fputc(',', f); + if (name) { + fputs(name, f); + } else { + /* + * cap-ng has very poor handling of + * CAP_LAST_CAP changes. This is the best + * we can do. + */ + printf("cap_%d", i); + } + n++; + } + } + return n; +} + +static void dump_one_secbit(bool *first, int *bits, int bit, const char *name) +{ + if (*bits & bit) { + if (!*first) + printf(","); + else + *first = false; + fputs(name, stdout); + *bits &= ~bit; + } +} + +static void dump_securebits(void) +{ + int bits = prctl(PR_GET_SECUREBITS, 0, 0, 0, 0); + if (bits < 0) { + warnx("PR_GET_SECUREBITS"); + return; + } + + printf("Securebits: "); + + bool first = true; + dump_one_secbit(&first, &bits, SECBIT_NOROOT, "noroot"); + dump_one_secbit(&first, &bits, SECBIT_NOROOT_LOCKED, "noroot_locked"); + dump_one_secbit(&first, &bits, SECBIT_NO_SETUID_FIXUP, + "no_setuid_fixup"); + dump_one_secbit(&first, &bits, + SECBIT_NO_SETUID_FIXUP_LOCKED, "no_setuid_fixup_locked"); + bits &= ~SECBIT_KEEP_CAPS; + dump_one_secbit(&first, &bits, SECBIT_KEEP_CAPS_LOCKED, + "keep_caps_locked"); + if (bits) { + if (!first) + printf(","); + else + first = false; + printf("0x%x", (unsigned)bits); + } + + if (first) + printf("[none]\n"); + else + printf("\n"); +} + +static void dump_label(const char *name) +{ + char buf[4097]; + ssize_t len; + int fd, e; + + fd = open("/proc/self/attr/current", O_RDONLY); + if (fd == -1) { + warnx(name); + return; + } + + len = read(fd, buf, sizeof(buf)); + e = errno; + close(fd); + errno = e; + if (len < 0) { + warnx(name); + return; + } + if ((size_t)len >= sizeof(buf) - 1) { + printf(_("%s: too long\n"), name); + return; + } + + buf[len] = 0; + if (len > 0 && buf[len-1] == '\n') + buf[len-1] = 0; + printf(_("%s: %s\n"), name, buf); +} + +static void dump_groups(void) +{ + int n = getgroups(0, 0); + if (n < 0) { + warnx("getgroups"); + return; + } + + gid_t *groups = alloca(n * sizeof(gid_t)); + n = getgroups(n, groups); + if (n < 0) { + warnx("getgroups"); + return; + } + + printf("Supplementary groups: "); + if (n == 0) { + printf("[none]"); + } else { + for (int i = 0; i < n; i++) { + if (i > 0) + printf(","); + printf("%ld", (long)groups[i]); + } + } + printf("\n"); +} + +static void dump(int dumplevel) +{ + int x; + + uid_t ru, eu, su; + if (getresuid(&ru, &eu, &su) == 0) { + printf("uid: %ld\n", (long)ru); + printf("euid: %ld\n", (long)eu); + /* Saved and fs uids always equal euid. */ + if (dumplevel >= 3) + printf("suid: %ld\n", (long)su); + } else { + warnx("getresuid"); + } + + gid_t rg, eg, sg; + if (getresgid(&rg, &eg, &sg) == 0) { + printf("gid: %ld\n", (long)rg); + printf("egid: %ld\n", (long)eg); + /* Saved and fs gids always equal egid. */ + if (dumplevel >= 3) + printf("sgid: %ld\n", (long)sg); + } else { + warnx("getresgid"); + } + + dump_groups(); + + x = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0); + if (x >= 0) + printf("no_new_privs: %d\n", x); + else + warnx("no_new_privs"); + + if (dumplevel >= 2) { + printf(_("Effective capabilities: ")); + if (print_caps(stdout, CAPNG_EFFECTIVE) == 0) + printf("[none]"); + printf("\n"); + + printf(_("Permitted capabilities: ")); + if (print_caps(stdout, CAPNG_PERMITTED) == 0) + printf("[none]"); + printf("\n"); + } + + printf(_("Inheritable capabilities: ")); + if (print_caps(stdout, CAPNG_INHERITABLE) == 0) + printf("[none]"); + printf("\n"); + + printf(_("Capability bounding set: ")); + if (print_caps(stdout, CAPNG_BOUNDING_SET) == 0) + printf("[none]"); + printf("\n"); + + dump_securebits(); + + if (access("/sys/fs/selinux", F_OK) == 0) + dump_label("SELinux label"); + + if (access("/sys/kernel/security/apparmor", F_OK) == 0) { + dump_label("AppArmor profile"); + } +} + +static void list_known_caps(void) +{ + for (int i = 0; i <= real_cap_last_cap(); i++) { + const char *name = capng_capability_to_name(i); + if (name) + printf("%s\n", name); + else + printf("cap %d [cap-ng broken]\n", i); + } +} + +static void parse_groups(struct privctx *opts, const char *str) +{ + char *groups = strdup(str); + char *buf = groups; /* We'll reuse it */ + char *c; + + opts->have_groups = true; + opts->num_groups = 0; + while ((c = strsep(&groups, ",")) != 0) + opts->num_groups++; + + /* Start again */ + strcpy(buf, str); /* It's exactly the right length */ + groups = buf; + + opts->groups = calloc(opts->num_groups, sizeof(gid_t)); + size_t i = 0; + while ((c = strsep(&groups, ",")) != 0) { + opts->groups[i++] = (gid_t)strtol_or_err(c, + _("Invalid supplementary group id")); + } + + free(groups); +} + +static void do_setresuid(const struct privctx *opts) +{ + uid_t ruid, euid, suid; + if (getresuid(&ruid, &euid, &suid) != 0) + err(SETPRIV_EXIT_PRIVERR, _("getresuid failed")); + if (opts->have_ruid) + ruid = opts->ruid; + if (opts->have_euid) + euid = opts->euid; + + /* Also copy effective to saved (for paranoia). */ + if (setresuid(ruid, euid, euid) != 0) + err(SETPRIV_EXIT_PRIVERR, _("setresuid failed")); +} + +static void do_setresgid(const struct privctx *opts) +{ + gid_t rgid, egid, sgid; + if (getresgid(&rgid, &egid, &sgid) != 0) + err(SETPRIV_EXIT_PRIVERR, _("getresgid failed")); + if (opts->have_rgid) + rgid = opts->rgid; + if (opts->have_egid) + egid = opts->egid; + + /* Also copy effective to saved (for paranoia). */ + if (setresgid(rgid, egid, egid) != 0) + err(SETPRIV_EXIT_PRIVERR, _("setresgid failed")); +} + +static void bump_cap(unsigned int cap) +{ + if (capng_have_capability(CAPNG_PERMITTED, cap)) + capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, cap); +} + +static void do_caps(capng_type_t type, const char *caps) +{ + char *my_caps = strdup(caps); /* Don't bother checking for error */ + + char *c; + while ((c = strsep(&my_caps, ",")) != 0) { + capng_act_t action; + if (*c == '+') + action = CAPNG_ADD; + else if (*c == '-') + action = CAPNG_DROP; + else + errx(EXIT_FAILURE, _("Bad capability string")); + + if (!strcmp(c+1, "all")) { + /* + * It would be really bad if -all didn't drop all + * caps. It's better to just fail. + */ + if (real_cap_last_cap() > CAP_LAST_CAP) + errx(SETPRIV_EXIT_PRIVERR, _("libcap-ng is too old for \"all\" caps")); + for (int i = 0; i <= CAP_LAST_CAP; i++) + capng_update(action, type, i); + } else { + int cap = capng_name_to_capability(c+1); + if (cap >= 0) + capng_update(action, type, cap); + else + errx(EXIT_FAILURE, _("Unknown capability \"%s\""), c+1); + } + } + + free(my_caps); +} + +static void parse_securebits(struct privctx *opts, const char *arg) +{ + opts->have_securebits = true; + opts->securebits = prctl(PR_GET_SECUREBITS, 0, 0, 0, 0); + if (opts->securebits < 0) + err(SETPRIV_EXIT_PRIVERR, _("PR_GET_SECUREBITS")); + + if (opts->securebits & ~(int)(SECBIT_NOROOT | SECBIT_NOROOT_LOCKED | + SECBIT_NO_SETUID_FIXUP | SECBIT_NO_SETUID_FIXUP_LOCKED | + SECBIT_KEEP_CAPS | SECBIT_KEEP_CAPS_LOCKED)) + { + errx(SETPRIV_EXIT_PRIVERR, _("Unrecognized securebit is set -- refusing to adjust")); + } + + char *buf = strdup(arg); + + char *c; + while ((c = strsep(&buf, ",")) != 0) { + if (*c != '+' && *c != '-') + errx(EXIT_FAILURE, _("Bad securebits string")); + + if (!strcmp(c+1, "all")) { + if (*c == '-') + opts->securebits = 0; + else + errx(EXIT_FAILURE, _("+all securebits is not allowed")); + } else { + int bit; + if (!strcmp(c+1, "noroot")) + bit = SECBIT_NOROOT; + else if (!strcmp(c+1, "noroot_locked")) + bit = SECBIT_NOROOT_LOCKED; + else if (!strcmp(c+1, "no_setuid_fixup")) + bit = SECBIT_NO_SETUID_FIXUP; + else if (!strcmp(c+1, "no_setuid_fixup_locked")) + bit = SECBIT_NO_SETUID_FIXUP_LOCKED; + else if (!strcmp(c+1, "keep_caps")) + errx(EXIT_FAILURE, _("Adjusting keep_caps makes no sense")); + else if (!strcmp(c+1, "keep_caps_locked")) + bit = SECBIT_KEEP_CAPS_LOCKED; /* sigh */ + else + errx(EXIT_FAILURE, _("Unrecognized securebit")); + + if (*c == '+') + opts->securebits |= bit; + else + opts->securebits &= ~bit; + } + } + + opts->securebits |= SECBIT_KEEP_CAPS; /* We need it, and it's reset on exec */ + + free(buf); +} + +static void do_selinux_label(const char *label) +{ + if (access("/sys/fs/selinux", F_OK) != 0) + errx(SETPRIV_EXIT_PRIVERR, _("SELinux is not running")); + + int fd = open("/proc/self/attr/exec", O_RDWR); + if (fd == -1) + err(SETPRIV_EXIT_PRIVERR, _("open /proc/self/attr/exec for selinux")); + + size_t len = strlen(label); + errno = 0; + if (write(fd, label, len) != (ssize_t)len) + err(SETPRIV_EXIT_PRIVERR, _("write /proc/self/attr/exec for selinux")); + + close(fd); +} + +static void do_apparmor_profile(const char *label) +{ + if (access("/sys/kernel/security/apparmor", F_OK) != 0) + errx(SETPRIV_EXIT_PRIVERR, _("AppArmor is not running")); + + FILE *f = fopen("/proc/self/attr/exec", "wx"); + if (!f) + err(SETPRIV_EXIT_PRIVERR, _("open /proc/self/attr/exec for apparmor")); + + if (fprintf(f, "changeprofile %s", label) < 0 || fflush(f) != 0 || fclose(f) != 0) + err(SETPRIV_EXIT_PRIVERR, _("write /proc/self/attr/exec for apparmor")); +} + +int main(int argc, char *argv[]) +{ + enum { + NNP = CHAR_MAX + 1, + RUID, + EUID, + RGID, + EGID, + REUID, + REGID, + CLEAR_GROUPS, + KEEP_GROUPS, + GROUPS, + INHCAPS, + LISTCAPS, + CAPBSET, + SECUREBITS, + SELINUX_LABEL, + APPARMOR_PROFILE + }; + + static const struct option longopts[] = { + { "dump", no_argument, 0, 'd' }, + { "nnp", no_argument, 0, NNP }, + { "no-new-privs", no_argument, 0, NNP }, + { "inh-caps", required_argument, 0, INHCAPS }, + { "list-caps", no_argument, 0, LISTCAPS }, + { "ruid", required_argument, 0, RUID }, + { "euid", required_argument, 0, EUID }, + { "rgid", required_argument, 0, RGID }, + { "egid", required_argument, 0, EGID }, + { "reuid", required_argument, 0, REUID }, + { "regid", required_argument, 0, REGID }, + { "clear-groups", no_argument, 0, CLEAR_GROUPS }, + { "keep-groups", no_argument, 0, KEEP_GROUPS }, + { "groups", required_argument, 0, GROUPS }, + { "bounding-set", required_argument, 0, CAPBSET }, + { "securebits", required_argument, 0, SECUREBITS }, + { "selinux-label", required_argument, 0, SELINUX_LABEL }, + { "apparmor-profile", required_argument, 0, APPARMOR_PROFILE }, + { "help", no_argument, 0, 'h' }, + { "version", no_argument, 0, 'V'}, + { NULL, 0, 0, 0 } + }; + + int c; + struct privctx opts; + int dumplevel = 0, total_opts = 0; + bool list_caps = false; + + setlocale(LC_MESSAGES, ""); + bindtextdomain(PACKAGE, LOCALEDIR); + textdomain(PACKAGE); + atexit(close_stdout); + + memset(&opts, 0, sizeof(opts)); + + while((c = getopt_long(argc, argv, "+dhV", longopts, NULL)) != -1) { + total_opts++; + switch(c) { + case 'd': + dumplevel++; + break; + case NNP: + if (opts.nnp) + errx(EXIT_FAILURE, _("Duplicate --no-new-privs option")); + opts.nnp = true; + break; + case RUID: + if (opts.have_ruid) + errx(EXIT_FAILURE, _("duplicate ruid")); + opts.have_ruid = true; + opts.ruid = strtol_or_err(optarg, + _("failed to parse ruid")); + break; + case EUID: + if (opts.have_euid) + errx(EXIT_FAILURE, _("duplicate euid")); + opts.have_euid = true; + opts.euid = strtol_or_err(optarg, + _("failed to parse euid")); + break; + case REUID: + if (opts.have_ruid || opts.have_euid) + errx(EXIT_FAILURE, _("duplicate ruid or euid")); + opts.have_ruid = opts.have_euid = true; + opts.ruid = opts.euid = strtol_or_err(optarg, + _("failed to parse reuid")); + break; + case RGID: + if (opts.have_rgid) + errx(EXIT_FAILURE, _("duplicate rgid")); + opts.have_rgid = true; + opts.rgid = strtol_or_err(optarg, + _("failed to parse rgid")); + break; + case EGID: + if (opts.have_egid) + errx(EXIT_FAILURE, _("duplicate egid")); + opts.have_egid = true; + opts.egid = strtol_or_err(optarg, + _("failed to parse egid")); + break; + case REGID: + if (opts.have_rgid || opts.have_egid) + errx(EXIT_FAILURE, _("duplicate rgid or egid")); + opts.have_rgid = opts.have_egid = true; + opts.rgid = opts.egid = strtol_or_err(optarg, + _("failed to parse regid")); + break; + case CLEAR_GROUPS: + if (opts.clear_groups) + errx(EXIT_FAILURE, _("Duplicate --clear-groups option")); + opts.clear_groups = true; + break; + case KEEP_GROUPS: + if (opts.keep_groups) + errx(EXIT_FAILURE, _("Duplicate --keep-groups option")); + opts.keep_groups = true; + break; + case GROUPS: + if (opts.have_groups) + errx(EXIT_FAILURE, _("Duplicate --groups option")); + parse_groups(&opts, optarg); + break; + case LISTCAPS: + list_caps = true; + break; + case INHCAPS: + if (opts.caps_to_inherit) + errx(EXIT_FAILURE, _("Duplicate --caps option")); + opts.caps_to_inherit = optarg; + break; + case CAPBSET: + if (opts.bounding_set) + errx(EXIT_FAILURE, _("Duplicate --bounding-set option")); + opts.bounding_set = optarg; + break; + case SECUREBITS: + if (opts.have_securebits) + errx(EXIT_FAILURE, _("Duplicate --securebits option")); + parse_securebits(&opts, optarg); + break; + case SELINUX_LABEL: + if (opts.selinux_label) + errx(EXIT_FAILURE, _("Duplicate --selinux-label option")); + opts.selinux_label = optarg; + break; + case APPARMOR_PROFILE: + if (opts.apparmor_profile) + errx(EXIT_FAILURE, _("Duplicate --apparmor-profile option")); + opts.apparmor_profile = optarg; + break; + case 'h': + usage(EXIT_SUCCESS); + case 'V': + printf(UTIL_LINUX_VERSION); + return EXIT_SUCCESS; + case '?': + usage(EXIT_FAILURE); + default: + errx(EXIT_FAILURE, _("Unrecognized option '%c'\n"), c); + } + } + + if (dumplevel) { + if (total_opts != dumplevel || optind < argc) + errx(EXIT_FAILURE, _("--dump is incompatible with all other options")); + dump(dumplevel); + return EXIT_SUCCESS; + } + + if (list_caps) { + if (total_opts != 1 || optind < argc) + errx(EXIT_FAILURE, _("--list-caps must be specified alone")); + list_known_caps(); + return EXIT_SUCCESS; + } + + if (optind >= argc) + errx(EXIT_FAILURE, _("No program specified")); + + if ((opts.have_rgid || opts.have_egid) + && !opts.keep_groups && !opts.clear_groups && !opts.have_groups) + errx(EXIT_FAILURE, _("--[re]gid requires --keep-groups, --clear-groups, or --groups")); + + if ((int)opts.keep_groups + (int)opts.clear_groups + + (int)opts.have_groups > 1) + errx(EXIT_FAILURE, _("Too many of --keep-groups, --clear-groups, or --groups")); + + if (opts.nnp) { + if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) == -1) + err(EXIT_FAILURE, _("PR_SET_NO_NEW_PRIVS failed")); + } + + if (opts.selinux_label) + do_selinux_label(opts.selinux_label); + if (opts.apparmor_profile) + do_apparmor_profile(opts.apparmor_profile); + + if (prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) == -1) + err(EXIT_FAILURE, _("PR_SET_KEEPCAPS failed")); + + /* + * We're going to want CAP_SETPCAP, CAP_SETUID, and CAP_SETGID + * if possible. + */ + bump_cap(CAP_SETPCAP); + bump_cap(CAP_SETUID); + bump_cap(CAP_SETGID); + if (capng_apply(CAPNG_SELECT_CAPS) != 0) + err(SETPRIV_EXIT_PRIVERR, _("activate capabilities")); + + if (opts.have_ruid || opts.have_euid) { + do_setresuid(&opts); + + /* KEEPCAPS doesn't work for the effective mask. */ + if (capng_apply(CAPNG_SELECT_CAPS) != 0) + err(SETPRIV_EXIT_PRIVERR, _("reactivate capabilities")); + } + + if (opts.have_rgid || opts.have_egid) + do_setresgid(&opts); + + if (opts.have_groups) { + if (setgroups(opts.num_groups, opts.groups) != 0) + err(SETPRIV_EXIT_PRIVERR, _("setgroups")); + } else if (opts.clear_groups) { + gid_t x = 0; + if (setgroups(0, &x) != 0) + err(SETPRIV_EXIT_PRIVERR, _("setgroups")); + } + + if (opts.have_securebits) { + if (prctl(PR_SET_SECUREBITS, opts.securebits, 0, 0, 0) != 0) + err(SETPRIV_EXIT_PRIVERR, _("PR_SET_SECUREBITS")); + } + + if (opts.bounding_set) { + do_caps(CAPNG_BOUNDING_SET, opts.bounding_set); + errno = EPERM; /* capng doesn't set errno if we're missing CAP_SETPCAP */ + if (capng_apply(CAPNG_SELECT_BOUNDS) != 0) + err(SETPRIV_EXIT_PRIVERR, _("apply bounding set")); + } + + if (opts.caps_to_inherit) { + do_caps(CAPNG_INHERITABLE, opts.caps_to_inherit); + if (capng_apply(CAPNG_SELECT_CAPS) != 0) + err(SETPRIV_EXIT_PRIVERR, _("apply capabilities")); + } + + execvp(argv[optind], argv + optind); + + err(EXIT_FAILURE, _("exec %s failed"), argv[optind]); +} -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe util-linux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
