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v4.10.11
 
  1/*
  2 * Copyright (c) 2014 Google, Inc.
  3 *
  4 * Licensed under the terms of the GNU GPL License version 2
  5 *
  6 * Selftests for execveat(2).
  7 */
  8
 
  9#define _GNU_SOURCE  /* to get O_PATH, AT_EMPTY_PATH */
 
 10#include <sys/sendfile.h>
 11#include <sys/stat.h>
 12#include <sys/syscall.h>
 13#include <sys/types.h>
 14#include <sys/wait.h>
 15#include <errno.h>
 16#include <fcntl.h>
 17#include <limits.h>
 18#include <stdio.h>
 19#include <stdlib.h>
 20#include <string.h>
 21#include <unistd.h>
 22
 
 
 
 
 
 23static char longpath[2 * PATH_MAX] = "";
 24static char *envp[] = { "IN_TEST=yes", NULL, NULL };
 25static char *argv[] = { "execveat", "99", NULL };
 26
 27static int execveat_(int fd, const char *path, char **argv, char **envp,
 28		     int flags)
 29{
 30#ifdef __NR_execveat
 31	return syscall(__NR_execveat, fd, path, argv, envp, flags);
 32#else
 33	errno = ENOSYS;
 34	return -1;
 35#endif
 36}
 37
 38#define check_execveat_fail(fd, path, flags, errno)	\
 39	_check_execveat_fail(fd, path, flags, errno, #errno)
 40static int _check_execveat_fail(int fd, const char *path, int flags,
 41				int expected_errno, const char *errno_str)
 42{
 
 43	int rc;
 44
 45	errno = 0;
 46	printf("Check failure of execveat(%d, '%s', %d) with %s... ",
 47		fd, path?:"(null)", flags, errno_str);
 
 48	rc = execveat_(fd, path, argv, envp, flags);
 49
 50	if (rc > 0) {
 51		printf("[FAIL] (unexpected success from execveat(2))\n");
 
 52		return 1;
 53	}
 54	if (errno != expected_errno) {
 55		printf("[FAIL] (expected errno %d (%s) not %d (%s)\n",
 56			expected_errno, strerror(expected_errno),
 57			errno, strerror(errno));
 
 58		return 1;
 59	}
 60	printf("[OK]\n");
 61	return 0;
 62}
 63
 64static int check_execveat_invoked_rc(int fd, const char *path, int flags,
 65				     int expected_rc, int expected_rc2)
 66{
 
 67	int status;
 68	int rc;
 69	pid_t child;
 70	int pathlen = path ? strlen(path) : 0;
 71
 72	if (pathlen > 40)
 73		printf("Check success of execveat(%d, '%.20s...%s', %d)... ",
 74			fd, path, (path + pathlen - 20), flags);
 
 75	else
 76		printf("Check success of execveat(%d, '%s', %d)... ",
 77			fd, path?:"(null)", flags);
 
 
 78	child = fork();
 79	if (child < 0) {
 80		printf("[FAIL] (fork() failed)\n");
 
 81		return 1;
 82	}
 83	if (child == 0) {
 84		/* Child: do execveat(). */
 85		rc = execveat_(fd, path, argv, envp, flags);
 86		printf("[FAIL]: execveat() failed, rc=%d errno=%d (%s)\n",
 87			rc, errno, strerror(errno));
 88		exit(1);  /* should not reach here */
 89	}
 90	/* Parent: wait for & check child's exit status. */
 91	rc = waitpid(child, &status, 0);
 92	if (rc != child) {
 93		printf("[FAIL] (waitpid(%d,...) returned %d)\n", child, rc);
 
 94		return 1;
 95	}
 96	if (!WIFEXITED(status)) {
 97		printf("[FAIL] (child %d did not exit cleanly, status=%08x)\n",
 98			child, status);
 
 99		return 1;
100	}
101	if ((WEXITSTATUS(status) != expected_rc) &&
102	    (WEXITSTATUS(status) != expected_rc2)) {
103		printf("[FAIL] (child %d exited with %d not %d nor %d)\n",
104			child, WEXITSTATUS(status), expected_rc, expected_rc2);
 
 
105		return 1;
106	}
107	printf("[OK]\n");
108	return 0;
109}
110
111static int check_execveat(int fd, const char *path, int flags)
112{
113	return check_execveat_invoked_rc(fd, path, flags, 99, 99);
114}
115
116static char *concat(const char *left, const char *right)
117{
118	char *result = malloc(strlen(left) + strlen(right) + 1);
119
120	strcpy(result, left);
121	strcat(result, right);
122	return result;
123}
124
125static int open_or_die(const char *filename, int flags)
126{
127	int fd = open(filename, flags);
128
129	if (fd < 0) {
130		printf("Failed to open '%s'; "
131			"check prerequisites are available\n", filename);
132		exit(1);
133	}
134	return fd;
135}
136
137static void exe_cp(const char *src, const char *dest)
138{
139	int in_fd = open_or_die(src, O_RDONLY);
140	int out_fd = open(dest, O_RDWR|O_CREAT|O_TRUNC, 0755);
141	struct stat info;
142
143	fstat(in_fd, &info);
144	sendfile(out_fd, in_fd, NULL, info.st_size);
145	close(in_fd);
146	close(out_fd);
147}
148
149#define XX_DIR_LEN 200
150static int check_execveat_pathmax(int dot_dfd, const char *src, int is_script)
151{
152	int fail = 0;
153	int ii, count, len;
154	char longname[XX_DIR_LEN + 1];
155	int fd;
156
157	if (*longpath == '\0') {
158		/* Create a filename close to PATH_MAX in length */
 
 
 
 
 
 
 
 
159		memset(longname, 'x', XX_DIR_LEN - 1);
160		longname[XX_DIR_LEN - 1] = '/';
161		longname[XX_DIR_LEN] = '\0';
162		count = (PATH_MAX - 3) / XX_DIR_LEN;
163		for (ii = 0; ii < count; ii++) {
164			strcat(longpath, longname);
165			mkdir(longpath, 0755);
166		}
167		len = (PATH_MAX - 3) - (count * XX_DIR_LEN);
168		if (len <= 0)
169			len = 1;
170		memset(longname, 'y', len);
171		longname[len] = '\0';
172		strcat(longpath, longname);
 
173	}
174	exe_cp(src, longpath);
175
176	/*
177	 * Execute as a pre-opened file descriptor, which works whether this is
178	 * a script or not (because the interpreter sees a filename like
179	 * "/dev/fd/20").
180	 */
181	fd = open(longpath, O_RDONLY);
182	if (fd > 0) {
183		printf("Invoke copy of '%s' via filename of length %zu:\n",
184			src, strlen(longpath));
185		fail += check_execveat(fd, "", AT_EMPTY_PATH);
186	} else {
187		printf("Failed to open length %zu filename, errno=%d (%s)\n",
188			strlen(longpath), errno, strerror(errno));
189		fail++;
190	}
191
192	/*
193	 * Execute as a long pathname relative to ".".  If this is a script,
194	 * the interpreter will launch but fail to open the script because its
195	 * name ("/dev/fd/5/xxx....") is bigger than PATH_MAX.
196	 *
197	 * The failure code is usually 127 (POSIX: "If a command is not found,
198	 * the exit status shall be 127."), but some systems give 126 (POSIX:
199	 * "If the command name is found, but it is not an executable utility,
200	 * the exit status shall be 126."), so allow either.
201	 */
202	if (is_script)
203		fail += check_execveat_invoked_rc(dot_dfd, longpath, 0,
 
204						  127, 126);
205	else
206		fail += check_execveat(dot_dfd, longpath, 0);
 
 
207
208	return fail;
209}
210
211static int run_tests(void)
212{
213	int fail = 0;
214	char *fullname = realpath("execveat", NULL);
215	char *fullname_script = realpath("script", NULL);
216	char *fullname_symlink = concat(fullname, ".symlink");
217	int subdir_dfd = open_or_die("subdir", O_DIRECTORY|O_RDONLY);
218	int subdir_dfd_ephemeral = open_or_die("subdir.ephemeral",
219					       O_DIRECTORY|O_RDONLY);
220	int dot_dfd = open_or_die(".", O_DIRECTORY|O_RDONLY);
 
221	int dot_dfd_path = open_or_die(".", O_DIRECTORY|O_RDONLY|O_PATH);
222	int dot_dfd_cloexec = open_or_die(".", O_DIRECTORY|O_RDONLY|O_CLOEXEC);
223	int fd = open_or_die("execveat", O_RDONLY);
224	int fd_path = open_or_die("execveat", O_RDONLY|O_PATH);
225	int fd_symlink = open_or_die("execveat.symlink", O_RDONLY);
226	int fd_denatured = open_or_die("execveat.denatured", O_RDONLY);
227	int fd_denatured_path = open_or_die("execveat.denatured",
228					    O_RDONLY|O_PATH);
229	int fd_script = open_or_die("script", O_RDONLY);
230	int fd_ephemeral = open_or_die("execveat.ephemeral", O_RDONLY);
231	int fd_ephemeral_path = open_or_die("execveat.path.ephemeral",
232					    O_RDONLY|O_PATH);
233	int fd_script_ephemeral = open_or_die("script.ephemeral", O_RDONLY);
234	int fd_cloexec = open_or_die("execveat", O_RDONLY|O_CLOEXEC);
235	int fd_script_cloexec = open_or_die("script", O_RDONLY|O_CLOEXEC);
236
237	/* Check if we have execveat at all, and bail early if not */
238	errno = 0;
239	execveat_(-1, NULL, NULL, NULL, 0);
240	if (errno == ENOSYS) {
241		printf("[FAIL] ENOSYS calling execveat - no kernel support?\n");
242		return 1;
243	}
244
245	/* Change file position to confirm it doesn't affect anything */
246	lseek(fd, 10, SEEK_SET);
247
248	/* Normal executable file: */
249	/*   dfd + path */
250	fail += check_execveat(subdir_dfd, "../execveat", 0);
251	fail += check_execveat(dot_dfd, "execveat", 0);
252	fail += check_execveat(dot_dfd_path, "execveat", 0);
253	/*   absolute path */
254	fail += check_execveat(AT_FDCWD, fullname, 0);
255	/*   absolute path with nonsense dfd */
256	fail += check_execveat(99, fullname, 0);
257	/*   fd + no path */
258	fail += check_execveat(fd, "", AT_EMPTY_PATH);
259	/*   O_CLOEXEC fd + no path */
260	fail += check_execveat(fd_cloexec, "", AT_EMPTY_PATH);
261	/*   O_PATH fd */
262	fail += check_execveat(fd_path, "", AT_EMPTY_PATH);
263
264	/* Mess with executable file that's already open: */
265	/*   fd + no path to a file that's been renamed */
266	rename("execveat.ephemeral", "execveat.moved");
267	fail += check_execveat(fd_ephemeral, "", AT_EMPTY_PATH);
268	/*   fd + no path to a file that's been deleted */
269	unlink("execveat.moved"); /* remove the file now fd open */
270	fail += check_execveat(fd_ephemeral, "", AT_EMPTY_PATH);
271
272	/* Mess with executable file that's already open with O_PATH */
273	/*   fd + no path to a file that's been deleted */
274	unlink("execveat.path.ephemeral");
275	fail += check_execveat(fd_ephemeral_path, "", AT_EMPTY_PATH);
276
277	/* Invalid argument failures */
278	fail += check_execveat_fail(fd, "", 0, ENOENT);
279	fail += check_execveat_fail(fd, NULL, AT_EMPTY_PATH, EFAULT);
280
281	/* Symlink to executable file: */
282	/*   dfd + path */
283	fail += check_execveat(dot_dfd, "execveat.symlink", 0);
284	fail += check_execveat(dot_dfd_path, "execveat.symlink", 0);
285	/*   absolute path */
286	fail += check_execveat(AT_FDCWD, fullname_symlink, 0);
287	/*   fd + no path, even with AT_SYMLINK_NOFOLLOW (already followed) */
288	fail += check_execveat(fd_symlink, "", AT_EMPTY_PATH);
289	fail += check_execveat(fd_symlink, "",
290			       AT_EMPTY_PATH|AT_SYMLINK_NOFOLLOW);
291
292	/* Symlink fails when AT_SYMLINK_NOFOLLOW set: */
293	/*   dfd + path */
294	fail += check_execveat_fail(dot_dfd, "execveat.symlink",
295				    AT_SYMLINK_NOFOLLOW, ELOOP);
296	fail += check_execveat_fail(dot_dfd_path, "execveat.symlink",
297				    AT_SYMLINK_NOFOLLOW, ELOOP);
298	/*   absolute path */
299	fail += check_execveat_fail(AT_FDCWD, fullname_symlink,
300				    AT_SYMLINK_NOFOLLOW, ELOOP);
301
 
 
 
 
302	/* Shell script wrapping executable file: */
303	/*   dfd + path */
304	fail += check_execveat(subdir_dfd, "../script", 0);
305	fail += check_execveat(dot_dfd, "script", 0);
306	fail += check_execveat(dot_dfd_path, "script", 0);
307	/*   absolute path */
308	fail += check_execveat(AT_FDCWD, fullname_script, 0);
309	/*   fd + no path */
310	fail += check_execveat(fd_script, "", AT_EMPTY_PATH);
311	fail += check_execveat(fd_script, "",
312			       AT_EMPTY_PATH|AT_SYMLINK_NOFOLLOW);
313	/*   O_CLOEXEC fd fails for a script (as script file inaccessible) */
314	fail += check_execveat_fail(fd_script_cloexec, "", AT_EMPTY_PATH,
315				    ENOENT);
316	fail += check_execveat_fail(dot_dfd_cloexec, "script", 0, ENOENT);
317
318	/* Mess with script file that's already open: */
319	/*   fd + no path to a file that's been renamed */
320	rename("script.ephemeral", "script.moved");
321	fail += check_execveat(fd_script_ephemeral, "", AT_EMPTY_PATH);
322	/*   fd + no path to a file that's been deleted */
323	unlink("script.moved"); /* remove the file while fd open */
324	fail += check_execveat(fd_script_ephemeral, "", AT_EMPTY_PATH);
325
326	/* Rename a subdirectory in the path: */
327	rename("subdir.ephemeral", "subdir.moved");
328	fail += check_execveat(subdir_dfd_ephemeral, "../script", 0);
329	fail += check_execveat(subdir_dfd_ephemeral, "script", 0);
330	/* Remove the subdir and its contents */
331	unlink("subdir.moved/script");
332	unlink("subdir.moved");
333	/* Shell loads via deleted subdir OK because name starts with .. */
334	fail += check_execveat(subdir_dfd_ephemeral, "../script", 0);
335	fail += check_execveat_fail(subdir_dfd_ephemeral, "script", 0, ENOENT);
336
337	/* Flag values other than AT_SYMLINK_NOFOLLOW => EINVAL */
338	fail += check_execveat_fail(dot_dfd, "execveat", 0xFFFF, EINVAL);
339	/* Invalid path => ENOENT */
340	fail += check_execveat_fail(dot_dfd, "no-such-file", 0, ENOENT);
341	fail += check_execveat_fail(dot_dfd_path, "no-such-file", 0, ENOENT);
342	fail += check_execveat_fail(AT_FDCWD, "no-such-file", 0, ENOENT);
343	/* Attempt to execute directory => EACCES */
344	fail += check_execveat_fail(dot_dfd, "", AT_EMPTY_PATH, EACCES);
345	/* Attempt to execute non-executable => EACCES */
346	fail += check_execveat_fail(dot_dfd, "Makefile", 0, EACCES);
347	fail += check_execveat_fail(fd_denatured, "", AT_EMPTY_PATH, EACCES);
348	fail += check_execveat_fail(fd_denatured_path, "", AT_EMPTY_PATH,
349				    EACCES);
350	/* Attempt to execute nonsense FD => EBADF */
351	fail += check_execveat_fail(99, "", AT_EMPTY_PATH, EBADF);
352	fail += check_execveat_fail(99, "execveat", 0, EBADF);
353	/* Attempt to execute relative to non-directory => ENOTDIR */
354	fail += check_execveat_fail(fd, "execveat", 0, ENOTDIR);
355
356	fail += check_execveat_pathmax(dot_dfd, "execveat", 0);
357	fail += check_execveat_pathmax(dot_dfd, "script", 1);
358	return fail;
359}
360
361static void prerequisites(void)
362{
363	int fd;
364	const char *script = "#!/bin/sh\nexit $*\n";
365
366	/* Create ephemeral copies of files */
367	exe_cp("execveat", "execveat.ephemeral");
368	exe_cp("execveat", "execveat.path.ephemeral");
369	exe_cp("script", "script.ephemeral");
370	mkdir("subdir.ephemeral", 0755);
371
372	fd = open("subdir.ephemeral/script", O_RDWR|O_CREAT|O_TRUNC, 0755);
373	write(fd, script, strlen(script));
374	close(fd);
 
 
375}
376
377int main(int argc, char **argv)
378{
379	int ii;
380	int rc;
381	const char *verbose = getenv("VERBOSE");
382
383	if (argc >= 2) {
384		/* If we are invoked with an argument, don't run tests. */
385		const char *in_test = getenv("IN_TEST");
386
387		if (verbose) {
388			printf("  invoked with:");
389			for (ii = 0; ii < argc; ii++)
390				printf(" [%d]='%s'", ii, argv[ii]);
391			printf("\n");
392		}
393
394		/* Check expected environment transferred. */
395		if (!in_test || strcmp(in_test, "yes") != 0) {
396			printf("[FAIL] (no IN_TEST=yes in env)\n");
397			return 1;
398		}
399
400		/* Use the final argument as an exit code. */
401		rc = atoi(argv[argc - 1]);
402		fflush(stdout);
403	} else {
 
 
404		prerequisites();
405		if (verbose)
406			envp[1] = "VERBOSE=1";
407		rc = run_tests();
408		if (rc > 0)
409			printf("%d tests failed\n", rc);
 
410	}
 
411	return rc;
412}
v6.9.4
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (c) 2014 Google, Inc.
  4 *
 
 
  5 * Selftests for execveat(2).
  6 */
  7
  8#ifndef _GNU_SOURCE
  9#define _GNU_SOURCE  /* to get O_PATH, AT_EMPTY_PATH */
 10#endif
 11#include <sys/sendfile.h>
 12#include <sys/stat.h>
 13#include <sys/syscall.h>
 14#include <sys/types.h>
 15#include <sys/wait.h>
 16#include <errno.h>
 17#include <fcntl.h>
 18#include <limits.h>
 19#include <stdio.h>
 20#include <stdlib.h>
 21#include <string.h>
 22#include <unistd.h>
 23
 24#include "../kselftest.h"
 25
 26#define TESTS_EXPECTED 51
 27#define TEST_NAME_LEN (PATH_MAX * 4)
 28
 29static char longpath[2 * PATH_MAX] = "";
 30static char *envp[] = { "IN_TEST=yes", NULL, NULL };
 31static char *argv[] = { "execveat", "99", NULL };
 32
 33static int execveat_(int fd, const char *path, char **argv, char **envp,
 34		     int flags)
 35{
 36#ifdef __NR_execveat
 37	return syscall(__NR_execveat, fd, path, argv, envp, flags);
 38#else
 39	errno = ENOSYS;
 40	return -1;
 41#endif
 42}
 43
 44#define check_execveat_fail(fd, path, flags, errno)	\
 45	_check_execveat_fail(fd, path, flags, errno, #errno)
 46static int _check_execveat_fail(int fd, const char *path, int flags,
 47				int expected_errno, const char *errno_str)
 48{
 49	char test_name[TEST_NAME_LEN];
 50	int rc;
 51
 52	errno = 0;
 53	snprintf(test_name, sizeof(test_name),
 54		 "Check failure of execveat(%d, '%s', %d) with %s",
 55		 fd, path?:"(null)", flags, errno_str);
 56	rc = execveat_(fd, path, argv, envp, flags);
 57
 58	if (rc > 0) {
 59		ksft_print_msg("unexpected success from execveat(2)\n");
 60		ksft_test_result_fail("%s\n", test_name);
 61		return 1;
 62	}
 63	if (errno != expected_errno) {
 64		ksft_print_msg("expected errno %d (%s) not %d (%s)\n",
 65			       expected_errno, strerror(expected_errno),
 66			       errno, strerror(errno));
 67		ksft_test_result_fail("%s\n", test_name);
 68		return 1;
 69	}
 70	ksft_test_result_pass("%s\n", test_name);
 71	return 0;
 72}
 73
 74static int check_execveat_invoked_rc(int fd, const char *path, int flags,
 75				     int expected_rc, int expected_rc2)
 76{
 77	char test_name[TEST_NAME_LEN];
 78	int status;
 79	int rc;
 80	pid_t child;
 81	int pathlen = path ? strlen(path) : 0;
 82
 83	if (pathlen > 40)
 84		snprintf(test_name, sizeof(test_name),
 85			 "Check success of execveat(%d, '%.20s...%s', %d)... ",
 86			 fd, path, (path + pathlen - 20), flags);
 87	else
 88		snprintf(test_name, sizeof(test_name),
 89			 "Check success of execveat(%d, '%s', %d)... ",
 90			 fd, path?:"(null)", flags);
 91
 92	child = fork();
 93	if (child < 0) {
 94		ksft_perror("fork() failed");
 95		ksft_test_result_fail("%s\n", test_name);
 96		return 1;
 97	}
 98	if (child == 0) {
 99		/* Child: do execveat(). */
100		rc = execveat_(fd, path, argv, envp, flags);
101		ksft_print_msg("child execveat() failed, rc=%d errno=%d (%s)\n",
102			       rc, errno, strerror(errno));
103		exit(errno);
104	}
105	/* Parent: wait for & check child's exit status. */
106	rc = waitpid(child, &status, 0);
107	if (rc != child) {
108		ksft_print_msg("waitpid(%d,...) returned %d\n", child, rc);
109		ksft_test_result_fail("%s\n", test_name);
110		return 1;
111	}
112	if (!WIFEXITED(status)) {
113		ksft_print_msg("child %d did not exit cleanly, status=%08x\n",
114			       child, status);
115		ksft_test_result_fail("%s\n", test_name);
116		return 1;
117	}
118	if ((WEXITSTATUS(status) != expected_rc) &&
119	    (WEXITSTATUS(status) != expected_rc2)) {
120		ksft_print_msg("child %d exited with %d not %d nor %d\n",
121			       child, WEXITSTATUS(status), expected_rc,
122			       expected_rc2);
123		ksft_test_result_fail("%s\n", test_name);
124		return 1;
125	}
126	ksft_test_result_pass("%s\n", test_name);
127	return 0;
128}
129
130static int check_execveat(int fd, const char *path, int flags)
131{
132	return check_execveat_invoked_rc(fd, path, flags, 99, 99);
133}
134
135static char *concat(const char *left, const char *right)
136{
137	char *result = malloc(strlen(left) + strlen(right) + 1);
138
139	strcpy(result, left);
140	strcat(result, right);
141	return result;
142}
143
144static int open_or_die(const char *filename, int flags)
145{
146	int fd = open(filename, flags);
147
148	if (fd < 0)
149		ksft_exit_fail_msg("Failed to open '%s'; "
150			"check prerequisites are available\n", filename);
 
 
151	return fd;
152}
153
154static void exe_cp(const char *src, const char *dest)
155{
156	int in_fd = open_or_die(src, O_RDONLY);
157	int out_fd = open(dest, O_RDWR|O_CREAT|O_TRUNC, 0755);
158	struct stat info;
159
160	fstat(in_fd, &info);
161	sendfile(out_fd, in_fd, NULL, info.st_size);
162	close(in_fd);
163	close(out_fd);
164}
165
166#define XX_DIR_LEN 200
167static int check_execveat_pathmax(int root_dfd, const char *src, int is_script)
168{
169	int fail = 0;
170	int ii, count, len;
171	char longname[XX_DIR_LEN + 1];
172	int fd;
173
174	if (*longpath == '\0') {
175		/* Create a filename close to PATH_MAX in length */
176		char *cwd = getcwd(NULL, 0);
177
178		if (!cwd) {
179			ksft_perror("Failed to getcwd()");
180			return 2;
181		}
182		strcpy(longpath, cwd);
183		strcat(longpath, "/");
184		memset(longname, 'x', XX_DIR_LEN - 1);
185		longname[XX_DIR_LEN - 1] = '/';
186		longname[XX_DIR_LEN] = '\0';
187		count = (PATH_MAX - 3 - strlen(cwd)) / XX_DIR_LEN;
188		for (ii = 0; ii < count; ii++) {
189			strcat(longpath, longname);
190			mkdir(longpath, 0755);
191		}
192		len = (PATH_MAX - 3 - strlen(cwd)) - (count * XX_DIR_LEN);
193		if (len <= 0)
194			len = 1;
195		memset(longname, 'y', len);
196		longname[len] = '\0';
197		strcat(longpath, longname);
198		free(cwd);
199	}
200	exe_cp(src, longpath);
201
202	/*
203	 * Execute as a pre-opened file descriptor, which works whether this is
204	 * a script or not (because the interpreter sees a filename like
205	 * "/dev/fd/20").
206	 */
207	fd = open(longpath, O_RDONLY);
208	if (fd > 0) {
209		ksft_print_msg("Invoke copy of '%s' via filename of length %zu:\n",
210			       src, strlen(longpath));
211		fail += check_execveat(fd, "", AT_EMPTY_PATH);
212	} else {
213		ksft_print_msg("Failed to open length %zu filename, errno=%d (%s)\n",
214			       strlen(longpath), errno, strerror(errno));
215		fail++;
216	}
217
218	/*
219	 * Execute as a long pathname relative to "/".  If this is a script,
220	 * the interpreter will launch but fail to open the script because its
221	 * name ("/dev/fd/5/xxx....") is bigger than PATH_MAX.
222	 *
223	 * The failure code is usually 127 (POSIX: "If a command is not found,
224	 * the exit status shall be 127."), but some systems give 126 (POSIX:
225	 * "If the command name is found, but it is not an executable utility,
226	 * the exit status shall be 126."), so allow either.
227	 */
228	if (is_script) {
229		ksft_print_msg("Invoke script via root_dfd and relative filename\n");
230		fail += check_execveat_invoked_rc(root_dfd, longpath + 1, 0,
231						  127, 126);
232	} else {
233		ksft_print_msg("Invoke exec via root_dfd and relative filename\n");
234		fail += check_execveat(root_dfd, longpath + 1, 0);
235	}
236
237	return fail;
238}
239
240static int run_tests(void)
241{
242	int fail = 0;
243	char *fullname = realpath("execveat", NULL);
244	char *fullname_script = realpath("script", NULL);
245	char *fullname_symlink = concat(fullname, ".symlink");
246	int subdir_dfd = open_or_die("subdir", O_DIRECTORY|O_RDONLY);
247	int subdir_dfd_ephemeral = open_or_die("subdir.ephemeral",
248					       O_DIRECTORY|O_RDONLY);
249	int dot_dfd = open_or_die(".", O_DIRECTORY|O_RDONLY);
250	int root_dfd = open_or_die("/", O_DIRECTORY|O_RDONLY);
251	int dot_dfd_path = open_or_die(".", O_DIRECTORY|O_RDONLY|O_PATH);
252	int dot_dfd_cloexec = open_or_die(".", O_DIRECTORY|O_RDONLY|O_CLOEXEC);
253	int fd = open_or_die("execveat", O_RDONLY);
254	int fd_path = open_or_die("execveat", O_RDONLY|O_PATH);
255	int fd_symlink = open_or_die("execveat.symlink", O_RDONLY);
256	int fd_denatured = open_or_die("execveat.denatured", O_RDONLY);
257	int fd_denatured_path = open_or_die("execveat.denatured",
258					    O_RDONLY|O_PATH);
259	int fd_script = open_or_die("script", O_RDONLY);
260	int fd_ephemeral = open_or_die("execveat.ephemeral", O_RDONLY);
261	int fd_ephemeral_path = open_or_die("execveat.path.ephemeral",
262					    O_RDONLY|O_PATH);
263	int fd_script_ephemeral = open_or_die("script.ephemeral", O_RDONLY);
264	int fd_cloexec = open_or_die("execveat", O_RDONLY|O_CLOEXEC);
265	int fd_script_cloexec = open_or_die("script", O_RDONLY|O_CLOEXEC);
266
267	/* Check if we have execveat at all, and bail early if not */
268	errno = 0;
269	execveat_(-1, NULL, NULL, NULL, 0);
270	if (errno == ENOSYS) {
271		ksft_exit_skip(
272			"ENOSYS calling execveat - no kernel support?\n");
273	}
274
275	/* Change file position to confirm it doesn't affect anything */
276	lseek(fd, 10, SEEK_SET);
277
278	/* Normal executable file: */
279	/*   dfd + path */
280	fail += check_execveat(subdir_dfd, "../execveat", 0);
281	fail += check_execveat(dot_dfd, "execveat", 0);
282	fail += check_execveat(dot_dfd_path, "execveat", 0);
283	/*   absolute path */
284	fail += check_execveat(AT_FDCWD, fullname, 0);
285	/*   absolute path with nonsense dfd */
286	fail += check_execveat(99, fullname, 0);
287	/*   fd + no path */
288	fail += check_execveat(fd, "", AT_EMPTY_PATH);
289	/*   O_CLOEXEC fd + no path */
290	fail += check_execveat(fd_cloexec, "", AT_EMPTY_PATH);
291	/*   O_PATH fd */
292	fail += check_execveat(fd_path, "", AT_EMPTY_PATH);
293
294	/* Mess with executable file that's already open: */
295	/*   fd + no path to a file that's been renamed */
296	rename("execveat.ephemeral", "execveat.moved");
297	fail += check_execveat(fd_ephemeral, "", AT_EMPTY_PATH);
298	/*   fd + no path to a file that's been deleted */
299	unlink("execveat.moved"); /* remove the file now fd open */
300	fail += check_execveat(fd_ephemeral, "", AT_EMPTY_PATH);
301
302	/* Mess with executable file that's already open with O_PATH */
303	/*   fd + no path to a file that's been deleted */
304	unlink("execveat.path.ephemeral");
305	fail += check_execveat(fd_ephemeral_path, "", AT_EMPTY_PATH);
306
307	/* Invalid argument failures */
308	fail += check_execveat_fail(fd, "", 0, ENOENT);
309	fail += check_execveat_fail(fd, NULL, AT_EMPTY_PATH, EFAULT);
310
311	/* Symlink to executable file: */
312	/*   dfd + path */
313	fail += check_execveat(dot_dfd, "execveat.symlink", 0);
314	fail += check_execveat(dot_dfd_path, "execveat.symlink", 0);
315	/*   absolute path */
316	fail += check_execveat(AT_FDCWD, fullname_symlink, 0);
317	/*   fd + no path, even with AT_SYMLINK_NOFOLLOW (already followed) */
318	fail += check_execveat(fd_symlink, "", AT_EMPTY_PATH);
319	fail += check_execveat(fd_symlink, "",
320			       AT_EMPTY_PATH|AT_SYMLINK_NOFOLLOW);
321
322	/* Symlink fails when AT_SYMLINK_NOFOLLOW set: */
323	/*   dfd + path */
324	fail += check_execveat_fail(dot_dfd, "execveat.symlink",
325				    AT_SYMLINK_NOFOLLOW, ELOOP);
326	fail += check_execveat_fail(dot_dfd_path, "execveat.symlink",
327				    AT_SYMLINK_NOFOLLOW, ELOOP);
328	/*   absolute path */
329	fail += check_execveat_fail(AT_FDCWD, fullname_symlink,
330				    AT_SYMLINK_NOFOLLOW, ELOOP);
331
332	/*  Non-regular file failure */
333	fail += check_execveat_fail(dot_dfd, "pipe", 0, EACCES);
334	unlink("pipe");
335
336	/* Shell script wrapping executable file: */
337	/*   dfd + path */
338	fail += check_execveat(subdir_dfd, "../script", 0);
339	fail += check_execveat(dot_dfd, "script", 0);
340	fail += check_execveat(dot_dfd_path, "script", 0);
341	/*   absolute path */
342	fail += check_execveat(AT_FDCWD, fullname_script, 0);
343	/*   fd + no path */
344	fail += check_execveat(fd_script, "", AT_EMPTY_PATH);
345	fail += check_execveat(fd_script, "",
346			       AT_EMPTY_PATH|AT_SYMLINK_NOFOLLOW);
347	/*   O_CLOEXEC fd fails for a script (as script file inaccessible) */
348	fail += check_execveat_fail(fd_script_cloexec, "", AT_EMPTY_PATH,
349				    ENOENT);
350	fail += check_execveat_fail(dot_dfd_cloexec, "script", 0, ENOENT);
351
352	/* Mess with script file that's already open: */
353	/*   fd + no path to a file that's been renamed */
354	rename("script.ephemeral", "script.moved");
355	fail += check_execveat(fd_script_ephemeral, "", AT_EMPTY_PATH);
356	/*   fd + no path to a file that's been deleted */
357	unlink("script.moved"); /* remove the file while fd open */
358	fail += check_execveat(fd_script_ephemeral, "", AT_EMPTY_PATH);
359
360	/* Rename a subdirectory in the path: */
361	rename("subdir.ephemeral", "subdir.moved");
362	fail += check_execveat(subdir_dfd_ephemeral, "../script", 0);
363	fail += check_execveat(subdir_dfd_ephemeral, "script", 0);
364	/* Remove the subdir and its contents */
365	unlink("subdir.moved/script");
366	unlink("subdir.moved");
367	/* Shell loads via deleted subdir OK because name starts with .. */
368	fail += check_execveat(subdir_dfd_ephemeral, "../script", 0);
369	fail += check_execveat_fail(subdir_dfd_ephemeral, "script", 0, ENOENT);
370
371	/* Flag values other than AT_SYMLINK_NOFOLLOW => EINVAL */
372	fail += check_execveat_fail(dot_dfd, "execveat", 0xFFFF, EINVAL);
373	/* Invalid path => ENOENT */
374	fail += check_execveat_fail(dot_dfd, "no-such-file", 0, ENOENT);
375	fail += check_execveat_fail(dot_dfd_path, "no-such-file", 0, ENOENT);
376	fail += check_execveat_fail(AT_FDCWD, "no-such-file", 0, ENOENT);
377	/* Attempt to execute directory => EACCES */
378	fail += check_execveat_fail(dot_dfd, "", AT_EMPTY_PATH, EACCES);
379	/* Attempt to execute non-executable => EACCES */
380	fail += check_execveat_fail(dot_dfd, "Makefile", 0, EACCES);
381	fail += check_execveat_fail(fd_denatured, "", AT_EMPTY_PATH, EACCES);
382	fail += check_execveat_fail(fd_denatured_path, "", AT_EMPTY_PATH,
383				    EACCES);
384	/* Attempt to execute nonsense FD => EBADF */
385	fail += check_execveat_fail(99, "", AT_EMPTY_PATH, EBADF);
386	fail += check_execveat_fail(99, "execveat", 0, EBADF);
387	/* Attempt to execute relative to non-directory => ENOTDIR */
388	fail += check_execveat_fail(fd, "execveat", 0, ENOTDIR);
389
390	fail += check_execveat_pathmax(root_dfd, "execveat", 0);
391	fail += check_execveat_pathmax(root_dfd, "script", 1);
392	return fail;
393}
394
395static void prerequisites(void)
396{
397	int fd;
398	const char *script = "#!/bin/bash\nexit $*\n";
399
400	/* Create ephemeral copies of files */
401	exe_cp("execveat", "execveat.ephemeral");
402	exe_cp("execveat", "execveat.path.ephemeral");
403	exe_cp("script", "script.ephemeral");
404	mkdir("subdir.ephemeral", 0755);
405
406	fd = open("subdir.ephemeral/script", O_RDWR|O_CREAT|O_TRUNC, 0755);
407	write(fd, script, strlen(script));
408	close(fd);
409
410	mkfifo("pipe", 0755);
411}
412
413int main(int argc, char **argv)
414{
415	int ii;
416	int rc;
417	const char *verbose = getenv("VERBOSE");
418
419	if (argc >= 2) {
420		/* If we are invoked with an argument, don't run tests. */
421		const char *in_test = getenv("IN_TEST");
422
423		if (verbose) {
424			ksft_print_msg("invoked with:\n");
425			for (ii = 0; ii < argc; ii++)
426				ksft_print_msg("\t[%d]='%s\n'", ii, argv[ii]);
 
427		}
428
429		/* Check expected environment transferred. */
430		if (!in_test || strcmp(in_test, "yes") != 0) {
431			ksft_print_msg("no IN_TEST=yes in env\n");
432			return 1;
433		}
434
435		/* Use the final argument as an exit code. */
436		rc = atoi(argv[argc - 1]);
437		exit(rc);
438	} else {
439		ksft_print_header();
440		ksft_set_plan(TESTS_EXPECTED);
441		prerequisites();
442		if (verbose)
443			envp[1] = "VERBOSE=1";
444		rc = run_tests();
445		if (rc > 0)
446			printf("%d tests failed\n", rc);
447		ksft_finished();
448	}
449
450	return rc;
451}