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// 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, ret;	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		ret = capng_get_caps_process();		if (ret == -1)			ksft_exit_fail_msg("capng_get_caps_process failed\n"); 		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){	int ret;	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));	} 	ret = capng_get_caps_process();	if (ret == -1)		ksft_exit_fail_msg("capng_get_caps_process failed\n"); 	/* 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;}