diff --git a/stdlib/tst-secure-getenv.c b/stdlib/tst-secure-getenv.c index a682b7493e..156c92fea2 100644 --- a/stdlib/tst-secure-getenv.c +++ b/stdlib/tst-secure-getenv.c @@ -30,156 +30,12 @@ #include #include +#include #include +#include #include static char MAGIC_ARGUMENT[] = "run-actual-test"; -#define MAGIC_STATUS 19 - -/* Return a GID which is not our current GID, but is present in the - supplementary group list. */ -static gid_t -choose_gid (void) -{ - const int count = 64; - gid_t groups[count]; - int ret = getgroups (count, groups); - if (ret < 0) - { - printf ("getgroups: %m\n"); - exit (1); - } - gid_t current = getgid (); - for (int i = 0; i < ret; ++i) - { - if (groups[i] != current) - return groups[i]; - } - return 0; -} - - -/* Copies the executable into a restricted directory, so that we can - safely make it SGID with the TARGET group ID. Then runs the - executable. */ -static int -run_executable_sgid (gid_t target) -{ - char *dirname = xasprintf ("%s/secure-getenv.%jd", - test_dir, (intmax_t) getpid ()); - char *execname = xasprintf ("%s/bin", dirname); - int infd = -1; - int outfd = -1; - int ret = -1; - if (mkdir (dirname, 0700) < 0) - { - printf ("mkdir: %m\n"); - goto err; - } - infd = open ("/proc/self/exe", O_RDONLY); - if (infd < 0) - { - printf ("open (/proc/self/exe): %m\n"); - goto err; - } - outfd = open (execname, O_WRONLY | O_CREAT | O_EXCL, 0700); - if (outfd < 0) - { - printf ("open (%s): %m\n", execname); - goto err; - } - char buf[4096]; - for (;;) - { - ssize_t rdcount = read (infd, buf, sizeof (buf)); - if (rdcount < 0) - { - printf ("read: %m\n"); - goto err; - } - if (rdcount == 0) - break; - char *p = buf; - char *end = buf + rdcount; - while (p != end) - { - ssize_t wrcount = write (outfd, buf, end - p); - if (wrcount == 0) - errno = ENOSPC; - if (wrcount <= 0) - { - printf ("write: %m\n"); - goto err; - } - p += wrcount; - } - } - if (fchown (outfd, getuid (), target) < 0) - { - printf ("fchown (%s): %m\n", execname); - goto err; - } - if (fchmod (outfd, 02750) < 0) - { - printf ("fchmod (%s): %m\n", execname); - goto err; - } - if (close (outfd) < 0) - { - printf ("close (outfd): %m\n"); - goto err; - } - if (close (infd) < 0) - { - printf ("close (infd): %m\n"); - goto err; - } - - int kid = fork (); - if (kid < 0) - { - printf ("fork: %m\n"); - goto err; - } - if (kid == 0) - { - /* Child process. */ - char *args[] = { execname, MAGIC_ARGUMENT, NULL }; - execve (execname, args, environ); - printf ("execve (%s): %m\n", execname); - _exit (1); - } - int status; - if (waitpid (kid, &status, 0) < 0) - { - printf ("waitpid: %m\n"); - goto err; - } - if (!WIFEXITED (status) || WEXITSTATUS (status) != MAGIC_STATUS) - { - printf ("Unexpected exit status %d from child process\n", - status); - goto err; - } - ret = 0; - -err: - if (outfd >= 0) - close (outfd); - if (infd >= 0) - close (infd); - if (execname) - { - unlink (execname); - free (execname); - } - if (dirname) - { - rmdir (dirname); - free (dirname); - } - return ret; -} static int do_test (void) @@ -201,15 +57,15 @@ do_test (void) exit (1); } - gid_t target = choose_gid (); - if (target == 0) - { - fprintf (stderr, - "Could not find a suitable GID for user %jd, skipping test\n", - (intmax_t) getuid ()); - exit (0); - } - return run_executable_sgid (target); + int status = support_capture_subprogram_self_sgid (MAGIC_ARGUMENT); + + if (WEXITSTATUS (status) == EXIT_UNSUPPORTED) + return EXIT_UNSUPPORTED; + + if (!WIFEXITED (status)) + FAIL_EXIT1 ("Unexpected exit status %d from child process\n", status); + + return 0; } static void @@ -218,23 +74,15 @@ alternative_main (int argc, char **argv) if (argc == 2 && strcmp (argv[1], MAGIC_ARGUMENT) == 0) { if (getgid () == getegid ()) - { - /* This can happen if the file system is mounted nosuid. */ - fprintf (stderr, "SGID failed: GID and EGID match (%jd)\n", - (intmax_t) getgid ()); - exit (MAGIC_STATUS); - } + /* This can happen if the file system is mounted nosuid. */ + FAIL_UNSUPPORTED ("SGID failed: GID and EGID match (%jd)\n", + (intmax_t) getgid ()); if (getenv ("PATH") == NULL) - { - printf ("PATH variable not present\n"); - exit (3); - } + FAIL_EXIT (3, "PATH variable not present\n"); if (secure_getenv ("PATH") != NULL) - { - printf ("PATH variable not filtered out\n"); - exit (4); - } - exit (MAGIC_STATUS); + FAIL_EXIT (4, "PATH variable not filtered out\n"); + + exit (EXIT_SUCCESS); } } diff --git a/support/capture_subprocess.h b/support/capture_subprocess.h index d5eac84d09..0ed1173a9f 100644 --- a/support/capture_subprocess.h +++ b/support/capture_subprocess.h @@ -41,6 +41,12 @@ struct support_capture_subprocess support_capture_subprocess struct support_capture_subprocess support_capture_subprogram (const char *file, char *const argv[]); +/* Copy the running program into a setgid binary and run it with CHILD_ID + argument. If execution is successful, return the exit status of the child + program, otherwise return a non-zero failure exit code. */ +int support_capture_subprogram_self_sgid + (char *child_id); + /* Deallocate the subprocess data captured by support_capture_subprocess. */ void support_capture_subprocess_free (struct support_capture_subprocess *); diff --git a/support/subprocess.h b/support/subprocess.h index c031878d94..a19335ee5d 100644 --- a/support/subprocess.h +++ b/support/subprocess.h @@ -38,6 +38,11 @@ struct support_subprocess support_subprocess struct support_subprocess support_subprogram (const char *file, char *const argv[]); +/* Invoke program FILE with ARGV arguments by using posix_spawn and wait for it + to complete. Return program exit status. */ +int support_subprogram_wait + (const char *file, char *const argv[]); + /* Wait for the subprocess indicated by PROC::PID. Return the status indicate by waitpid call. */ int support_process_wait (struct support_subprocess *proc); diff --git a/support/support_capture_subprocess.c b/support/support_capture_subprocess.c index 7b3d96c305..c64dcf5caf 100644 --- a/support/support_capture_subprocess.c +++ b/support/support_capture_subprocess.c @@ -20,11 +20,14 @@ #include #include +#include #include #include #include #include #include +#include +#include static void transfer (const char *what, struct pollfd *pfd, struct xmemstream *stream) @@ -102,6 +105,129 @@ support_capture_subprogram (const char *file, char *const argv[]) return result; } +/* Copies the executable into a restricted directory, so that we can + safely make it SGID with the TARGET group ID. Then runs the + executable. */ +static int +copy_and_spawn_sgid (char *child_id, gid_t gid) +{ + char *dirname = xasprintf ("%s/tst-tunables-setuid.%jd", + test_dir, (intmax_t) getpid ()); + char *execname = xasprintf ("%s/bin", dirname); + int infd = -1; + int outfd = -1; + int ret = 1, status = 1; + + TEST_VERIFY (mkdir (dirname, 0700) == 0); + if (support_record_failure_is_failed ()) + goto err; + + infd = open ("/proc/self/exe", O_RDONLY); + if (infd < 0) + FAIL_UNSUPPORTED ("unsupported: Cannot read binary from procfs\n"); + + outfd = open (execname, O_WRONLY | O_CREAT | O_EXCL, 0700); + TEST_VERIFY (outfd >= 0); + if (support_record_failure_is_failed ()) + goto err; + + char buf[4096]; + for (;;) + { + ssize_t rdcount = read (infd, buf, sizeof (buf)); + TEST_VERIFY (rdcount >= 0); + if (support_record_failure_is_failed ()) + goto err; + if (rdcount == 0) + break; + char *p = buf; + char *end = buf + rdcount; + while (p != end) + { + ssize_t wrcount = write (outfd, buf, end - p); + if (wrcount == 0) + errno = ENOSPC; + TEST_VERIFY (wrcount > 0); + if (support_record_failure_is_failed ()) + goto err; + p += wrcount; + } + } + TEST_VERIFY (fchown (outfd, getuid (), gid) == 0); + if (support_record_failure_is_failed ()) + goto err; + TEST_VERIFY (fchmod (outfd, 02750) == 0); + if (support_record_failure_is_failed ()) + goto err; + TEST_VERIFY (close (outfd) == 0); + if (support_record_failure_is_failed ()) + goto err; + TEST_VERIFY (close (infd) == 0); + if (support_record_failure_is_failed ()) + goto err; + + /* We have the binary, now spawn the subprocess. Avoid using + support_subprogram because we only want the program exit status, not the + contents. */ + ret = 0; + + char * const args[] = {execname, child_id, NULL}; + + status = support_subprogram_wait (args[0], args); + +err: + if (outfd >= 0) + close (outfd); + if (infd >= 0) + close (infd); + if (execname != NULL) + { + unlink (execname); + free (execname); + } + if (dirname != NULL) + { + rmdir (dirname); + free (dirname); + } + + if (ret != 0) + FAIL_EXIT1("Failed to make sgid executable for test\n"); + + return status; +} + +int +support_capture_subprogram_self_sgid (char *child_id) +{ + gid_t target = 0; + const int count = 64; + gid_t groups[count]; + + /* Get a GID which is not our current GID, but is present in the + supplementary group list. */ + int ret = getgroups (count, groups); + if (ret < 0) + FAIL_UNSUPPORTED("Could not get group list for user %jd\n", + (intmax_t) getuid ()); + + gid_t current = getgid (); + for (int i = 0; i < ret; ++i) + { + if (groups[i] != current) + { + target = groups[i]; + break; + } + } + + if (target == 0) + FAIL_UNSUPPORTED("Could not find a suitable GID for user %jd\n", + (intmax_t) getuid ()); + + return copy_and_spawn_sgid (child_id, target); +} + void support_capture_subprocess_free (struct support_capture_subprocess *p) { diff --git a/support/support_subprocess.c b/support/support_subprocess.c index ae03c4b473..97e481e2d9 100644 --- a/support/support_subprocess.c +++ b/support/support_subprocess.c @@ -92,6 +92,19 @@ support_subprogram (const char *file, char *const argv[]) return result; } +int +support_subprogram_wait (const char *file, char *const argv[]) +{ + posix_spawn_file_actions_t fa; + + posix_spawn_file_actions_init (&fa); + struct support_subprocess res = support_subprocess_init (); + + res.pid = xposix_spawn (file, &fa, NULL, argv, environ); + + return support_process_wait (&res); +} + int support_process_wait (struct support_subprocess *proc) {