| // SPDX-License-Identifier: GPL-2.0 |
| #define _GNU_SOURCE |
| |
| #include <cap-ng.h> |
| #include <linux/capability.h> |
| #include <stdbool.h> |
| #include <string.h> |
| #include <stdio.h> |
| #include <fcntl.h> |
| #include <errno.h> |
| #include <stdarg.h> |
| #include <sched.h> |
| #include <sys/mount.h> |
| #include <limits.h> |
| #include <libgen.h> |
| #include <malloc.h> |
| #include <sys/wait.h> |
| #include <sys/prctl.h> |
| #include <sys/stat.h> |
| |
| #include "../kselftest.h" |
| |
| static int nerrs; |
| static pid_t mpid; /* main() pid is used to avoid duplicate test counts */ |
| |
| static void vmaybe_write_file(bool enoent_ok, char *filename, char *fmt, va_list ap) |
| { |
| char buf[4096]; |
| int fd; |
| ssize_t written; |
| int buf_len; |
| |
| buf_len = vsnprintf(buf, sizeof(buf), fmt, ap); |
| if (buf_len < 0) |
| ksft_exit_fail_msg("vsnprintf failed - %s\n", strerror(errno)); |
| |
| if (buf_len >= sizeof(buf)) |
| ksft_exit_fail_msg("vsnprintf output truncated\n"); |
| |
| |
| fd = open(filename, O_WRONLY); |
| if (fd < 0) { |
| if ((errno == ENOENT) && enoent_ok) |
| return; |
| ksft_exit_fail_msg("open of %s failed - %s\n", |
| filename, strerror(errno)); |
| } |
| written = write(fd, buf, buf_len); |
| if (written != buf_len) { |
| if (written >= 0) { |
| ksft_exit_fail_msg("short write to %s\n", filename); |
| } else { |
| ksft_exit_fail_msg("write to %s failed - %s\n", |
| filename, strerror(errno)); |
| } |
| } |
| if (close(fd) != 0) { |
| ksft_exit_fail_msg("close of %s failed - %s\n", |
| filename, strerror(errno)); |
| } |
| } |
| |
| static void maybe_write_file(char *filename, char *fmt, ...) |
| { |
| va_list ap; |
| |
| va_start(ap, fmt); |
| vmaybe_write_file(true, filename, fmt, ap); |
| va_end(ap); |
| } |
| |
| static void write_file(char *filename, char *fmt, ...) |
| { |
| va_list ap; |
| |
| va_start(ap, fmt); |
| vmaybe_write_file(false, filename, fmt, ap); |
| va_end(ap); |
| } |
| |
| static bool create_and_enter_ns(uid_t inner_uid) |
| { |
| uid_t outer_uid; |
| gid_t outer_gid; |
| int i; |
| bool have_outer_privilege; |
| |
| outer_uid = getuid(); |
| outer_gid = getgid(); |
| |
| if (outer_uid == 0 && unshare(CLONE_NEWNS) == 0) { |
| ksft_print_msg("[NOTE]\tUsing global UIDs for tests\n"); |
| if (prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) != 0) |
| ksft_exit_fail_msg("PR_SET_KEEPCAPS - %s\n", |
| strerror(errno)); |
| if (setresuid(inner_uid, inner_uid, -1) != 0) |
| ksft_exit_fail_msg("setresuid - %s\n", strerror(errno)); |
| |
| // Re-enable effective caps |
| capng_get_caps_process(); |
| for (i = 0; i < CAP_LAST_CAP; i++) |
| if (capng_have_capability(CAPNG_PERMITTED, i)) |
| capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, i); |
| if (capng_apply(CAPNG_SELECT_CAPS) != 0) |
| ksft_exit_fail_msg( |
| "capng_apply - %s\n", strerror(errno)); |
| |
| have_outer_privilege = true; |
| } else if (unshare(CLONE_NEWUSER | CLONE_NEWNS) == 0) { |
| ksft_print_msg("[NOTE]\tUsing a user namespace for tests\n"); |
| maybe_write_file("/proc/self/setgroups", "deny"); |
| write_file("/proc/self/uid_map", "%d %d 1", inner_uid, outer_uid); |
| write_file("/proc/self/gid_map", "0 %d 1", outer_gid); |
| |
| have_outer_privilege = false; |
| } else { |
| ksft_exit_skip("must be root or be able to create a userns\n"); |
| } |
| |
| if (mount("none", "/", NULL, MS_REC | MS_PRIVATE, NULL) != 0) |
| ksft_exit_fail_msg("remount everything private - %s\n", |
| strerror(errno)); |
| |
| return have_outer_privilege; |
| } |
| |
| static void chdir_to_tmpfs(void) |
| { |
| char cwd[PATH_MAX]; |
| if (getcwd(cwd, sizeof(cwd)) != cwd) |
| ksft_exit_fail_msg("getcwd - %s\n", strerror(errno)); |
| |
| if (mount("private_tmp", ".", "tmpfs", 0, "mode=0777") != 0) |
| ksft_exit_fail_msg("mount private tmpfs - %s\n", |
| strerror(errno)); |
| |
| if (chdir(cwd) != 0) |
| ksft_exit_fail_msg("chdir to private tmpfs - %s\n", |
| strerror(errno)); |
| } |
| |
| static void copy_fromat_to(int fromfd, const char *fromname, const char *toname) |
| { |
| int from = openat(fromfd, fromname, O_RDONLY); |
| if (from == -1) |
| ksft_exit_fail_msg("open copy source - %s\n", strerror(errno)); |
| |
| int to = open(toname, O_CREAT | O_WRONLY | O_EXCL, 0700); |
| |
| while (true) { |
| char buf[4096]; |
| ssize_t sz = read(from, buf, sizeof(buf)); |
| if (sz == 0) |
| break; |
| if (sz < 0) |
| ksft_exit_fail_msg("read - %s\n", strerror(errno)); |
| |
| if (write(to, buf, sz) != sz) |
| /* no short writes on tmpfs */ |
| ksft_exit_fail_msg("write - %s\n", strerror(errno)); |
| } |
| |
| close(from); |
| close(to); |
| } |
| |
| static bool fork_wait(void) |
| { |
| pid_t child = fork(); |
| if (child == 0) { |
| nerrs = 0; |
| return true; |
| } else if (child > 0) { |
| int status; |
| if (waitpid(child, &status, 0) != child || |
| !WIFEXITED(status)) { |
| ksft_print_msg("Child died\n"); |
| nerrs++; |
| } else if (WEXITSTATUS(status) != 0) { |
| ksft_print_msg("Child failed\n"); |
| nerrs++; |
| } else { |
| /* don't print this message for mpid */ |
| if (getpid() != mpid) |
| ksft_test_result_pass("Passed\n"); |
| } |
| return false; |
| } else { |
| ksft_exit_fail_msg("fork - %s\n", strerror(errno)); |
| return false; |
| } |
| } |
| |
| static void exec_other_validate_cap(const char *name, |
| bool eff, bool perm, bool inh, bool ambient) |
| { |
| execl(name, name, (eff ? "1" : "0"), |
| (perm ? "1" : "0"), (inh ? "1" : "0"), (ambient ? "1" : "0"), |
| NULL); |
| ksft_exit_fail_msg("execl - %s\n", strerror(errno)); |
| } |
| |
| static void exec_validate_cap(bool eff, bool perm, bool inh, bool ambient) |
| { |
| exec_other_validate_cap("./validate_cap", eff, perm, inh, ambient); |
| } |
| |
| static int do_tests(int uid, const char *our_path) |
| { |
| bool have_outer_privilege = create_and_enter_ns(uid); |
| |
| int ourpath_fd = open(our_path, O_RDONLY | O_DIRECTORY); |
| if (ourpath_fd == -1) |
| ksft_exit_fail_msg("open '%s' - %s\n", |
| our_path, strerror(errno)); |
| |
| chdir_to_tmpfs(); |
| |
| copy_fromat_to(ourpath_fd, "validate_cap", "validate_cap"); |
| |
| if (have_outer_privilege) { |
| uid_t gid = getegid(); |
| |
| copy_fromat_to(ourpath_fd, "validate_cap", |
| "validate_cap_suidroot"); |
| if (chown("validate_cap_suidroot", 0, -1) != 0) |
| ksft_exit_fail_msg("chown - %s\n", strerror(errno)); |
| if (chmod("validate_cap_suidroot", S_ISUID | 0700) != 0) |
| ksft_exit_fail_msg("chmod - %s\n", strerror(errno)); |
| |
| copy_fromat_to(ourpath_fd, "validate_cap", |
| "validate_cap_suidnonroot"); |
| if (chown("validate_cap_suidnonroot", uid + 1, -1) != 0) |
| ksft_exit_fail_msg("chown - %s\n", strerror(errno)); |
| if (chmod("validate_cap_suidnonroot", S_ISUID | 0700) != 0) |
| ksft_exit_fail_msg("chmod - %s\n", strerror(errno)); |
| |
| copy_fromat_to(ourpath_fd, "validate_cap", |
| "validate_cap_sgidroot"); |
| if (chown("validate_cap_sgidroot", -1, 0) != 0) |
| ksft_exit_fail_msg("chown - %s\n", strerror(errno)); |
| if (chmod("validate_cap_sgidroot", S_ISGID | 0710) != 0) |
| ksft_exit_fail_msg("chmod - %s\n", strerror(errno)); |
| |
| copy_fromat_to(ourpath_fd, "validate_cap", |
| "validate_cap_sgidnonroot"); |
| if (chown("validate_cap_sgidnonroot", -1, gid + 1) != 0) |
| ksft_exit_fail_msg("chown - %s\n", strerror(errno)); |
| if (chmod("validate_cap_sgidnonroot", S_ISGID | 0710) != 0) |
| ksft_exit_fail_msg("chmod - %s\n", strerror(errno)); |
| } |
| |
| capng_get_caps_process(); |
| |
| /* Make sure that i starts out clear */ |
| capng_update(CAPNG_DROP, CAPNG_INHERITABLE, CAP_NET_BIND_SERVICE); |
| if (capng_apply(CAPNG_SELECT_CAPS) != 0) |
| ksft_exit_fail_msg("capng_apply - %s\n", strerror(errno)); |
| |
| if (uid == 0) { |
| ksft_print_msg("[RUN]\tRoot => ep\n"); |
| if (fork_wait()) |
| exec_validate_cap(true, true, false, false); |
| } else { |
| ksft_print_msg("[RUN]\tNon-root => no caps\n"); |
| if (fork_wait()) |
| exec_validate_cap(false, false, false, false); |
| } |
| |
| ksft_print_msg("Check cap_ambient manipulation rules\n"); |
| |
| /* We should not be able to add ambient caps yet. */ |
| if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, CAP_NET_BIND_SERVICE, 0, 0, 0) != -1 || errno != EPERM) { |
| if (errno == EINVAL) |
| ksft_test_result_fail( |
| "PR_CAP_AMBIENT_RAISE isn't supported\n"); |
| else |
| ksft_test_result_fail( |
| "PR_CAP_AMBIENT_RAISE should have failed eith EPERM on a non-inheritable cap\n"); |
| return 1; |
| } |
| ksft_test_result_pass( |
| "PR_CAP_AMBIENT_RAISE failed on non-inheritable cap\n"); |
| |
| capng_update(CAPNG_ADD, CAPNG_INHERITABLE, CAP_NET_RAW); |
| capng_update(CAPNG_DROP, CAPNG_PERMITTED, CAP_NET_RAW); |
| capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_NET_RAW); |
| if (capng_apply(CAPNG_SELECT_CAPS) != 0) |
| ksft_exit_fail_msg("capng_apply - %s\n", strerror(errno)); |
| if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, CAP_NET_RAW, 0, 0, 0) != -1 || errno != EPERM) { |
| ksft_test_result_fail( |
| "PR_CAP_AMBIENT_RAISE should have failed on a non-permitted cap\n"); |
| return 1; |
| } |
| ksft_test_result_pass( |
| "PR_CAP_AMBIENT_RAISE failed on non-permitted cap\n"); |
| |
| capng_update(CAPNG_ADD, CAPNG_INHERITABLE, CAP_NET_BIND_SERVICE); |
| if (capng_apply(CAPNG_SELECT_CAPS) != 0) |
| ksft_exit_fail_msg("capng_apply - %s\n", strerror(errno)); |
| if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, CAP_NET_BIND_SERVICE, 0, 0, 0) != 0) { |
| ksft_test_result_fail( |
| "PR_CAP_AMBIENT_RAISE should have succeeded\n"); |
| return 1; |
| } |
| ksft_test_result_pass("PR_CAP_AMBIENT_RAISE worked\n"); |
| |
| if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_IS_SET, CAP_NET_BIND_SERVICE, 0, 0, 0) != 1) { |
| ksft_test_result_fail("PR_CAP_AMBIENT_IS_SET is broken\n"); |
| return 1; |
| } |
| |
| if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_CLEAR_ALL, 0, 0, 0, 0) != 0) |
| ksft_exit_fail_msg("PR_CAP_AMBIENT_CLEAR_ALL - %s\n", |
| strerror(errno)); |
| |
| if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_IS_SET, CAP_NET_BIND_SERVICE, 0, 0, 0) != 0) { |
| ksft_test_result_fail( |
| "PR_CAP_AMBIENT_CLEAR_ALL didn't work\n"); |
| return 1; |
| } |
| |
| if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, CAP_NET_BIND_SERVICE, 0, 0, 0) != 0) |
| ksft_exit_fail_msg("PR_CAP_AMBIENT_RAISE - %s\n", |
| strerror(errno)); |
| |
| capng_update(CAPNG_DROP, CAPNG_INHERITABLE, CAP_NET_BIND_SERVICE); |
| if (capng_apply(CAPNG_SELECT_CAPS) != 0) |
| ksft_exit_fail_msg("capng_apply - %s\n", strerror(errno)); |
| |
| if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_IS_SET, CAP_NET_BIND_SERVICE, 0, 0, 0) != 0) { |
| ksft_test_result_fail("Dropping I should have dropped A\n"); |
| return 1; |
| } |
| |
| ksft_test_result_pass("Basic manipulation appears to work\n"); |
| |
| capng_update(CAPNG_ADD, CAPNG_INHERITABLE, CAP_NET_BIND_SERVICE); |
| if (capng_apply(CAPNG_SELECT_CAPS) != 0) |
| ksft_exit_fail_msg("capng_apply - %s\n", strerror(errno)); |
| if (uid == 0) { |
| ksft_print_msg("[RUN]\tRoot +i => eip\n"); |
| if (fork_wait()) |
| exec_validate_cap(true, true, true, false); |
| } else { |
| ksft_print_msg("[RUN]\tNon-root +i => i\n"); |
| if (fork_wait()) |
| exec_validate_cap(false, false, true, false); |
| } |
| |
| if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, CAP_NET_BIND_SERVICE, 0, 0, 0) != 0) |
| ksft_exit_fail_msg("PR_CAP_AMBIENT_RAISE - %s\n", |
| strerror(errno)); |
| |
| ksft_print_msg("[RUN]\tUID %d +ia => eipa\n", uid); |
| if (fork_wait()) |
| exec_validate_cap(true, true, true, true); |
| |
| /* The remaining tests need real privilege */ |
| |
| if (!have_outer_privilege) { |
| ksft_test_result_skip("SUID/SGID tests (needs privilege)\n"); |
| goto done; |
| } |
| |
| if (uid == 0) { |
| ksft_print_msg("[RUN]\tRoot +ia, suidroot => eipa\n"); |
| if (fork_wait()) |
| exec_other_validate_cap("./validate_cap_suidroot", |
| true, true, true, true); |
| |
| ksft_print_msg("[RUN]\tRoot +ia, suidnonroot => ip\n"); |
| if (fork_wait()) |
| exec_other_validate_cap("./validate_cap_suidnonroot", |
| false, true, true, false); |
| |
| ksft_print_msg("[RUN]\tRoot +ia, sgidroot => eipa\n"); |
| if (fork_wait()) |
| exec_other_validate_cap("./validate_cap_sgidroot", |
| true, true, true, true); |
| |
| if (fork_wait()) { |
| ksft_print_msg( |
| "[RUN]\tRoot, gid != 0, +ia, sgidroot => eip\n"); |
| if (setresgid(1, 1, 1) != 0) |
| ksft_exit_fail_msg("setresgid - %s\n", |
| strerror(errno)); |
| exec_other_validate_cap("./validate_cap_sgidroot", |
| true, true, true, false); |
| } |
| |
| ksft_print_msg("[RUN]\tRoot +ia, sgidnonroot => eip\n"); |
| if (fork_wait()) |
| exec_other_validate_cap("./validate_cap_sgidnonroot", |
| true, true, true, false); |
| } else { |
| ksft_print_msg("[RUN]\tNon-root +ia, sgidnonroot => i\n"); |
| if (fork_wait()) |
| exec_other_validate_cap("./validate_cap_sgidnonroot", |
| false, false, true, false); |
| |
| if (fork_wait()) { |
| ksft_print_msg("[RUN]\tNon-root +ia, sgidroot => i\n"); |
| if (setresgid(1, 1, 1) != 0) |
| ksft_exit_fail_msg("setresgid - %s\n", |
| strerror(errno)); |
| exec_other_validate_cap("./validate_cap_sgidroot", |
| false, false, true, false); |
| } |
| } |
| |
| done: |
| ksft_print_cnts(); |
| return nerrs ? 1 : 0; |
| } |
| |
| int main(int argc, char **argv) |
| { |
| char *tmp1, *tmp2, *our_path; |
| |
| /* Find our path */ |
| tmp1 = strdup(argv[0]); |
| if (!tmp1) |
| ksft_exit_fail_msg("strdup - %s\n", strerror(errno)); |
| tmp2 = dirname(tmp1); |
| our_path = strdup(tmp2); |
| if (!our_path) |
| ksft_exit_fail_msg("strdup - %s\n", strerror(errno)); |
| free(tmp1); |
| |
| mpid = getpid(); |
| |
| if (fork_wait()) { |
| ksft_print_header(); |
| ksft_set_plan(12); |
| ksft_print_msg("[RUN]\t+++ Tests with uid == 0 +++\n"); |
| return do_tests(0, our_path); |
| } |
| |
| ksft_print_msg("==================================================\n"); |
| |
| if (fork_wait()) { |
| ksft_print_header(); |
| ksft_set_plan(9); |
| ksft_print_msg("[RUN]\t+++ Tests with uid != 0 +++\n"); |
| return do_tests(1, our_path); |
| } |
| |
| return nerrs ? 1 : 0; |
| } |
