| /* Copyright (C) 2012-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library 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 |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| /* Test that secure_getenv works by invoking the test as a SGID |
| program with a group ID from the supplementary group list. This |
| test can fail spuriously if the user is not a member of a suitable |
| supplementary group. */ |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <stdlib.h> |
| #include <stdint.h> |
| #include <stdio.h> |
| #include <string.h> |
| #include <sys/stat.h> |
| #include <sys/wait.h> |
| #include <unistd.h> |
| |
| #include <support/support.h> |
| #include <support/test-driver.h> |
| |
| 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) |
| { |
| if (getenv ("PATH") == NULL) |
| { |
| printf ("PATH not set\n"); |
| exit (1); |
| } |
| if (secure_getenv ("PATH") == NULL) |
| { |
| printf ("PATH not set according to secure_getenv\n"); |
| exit (1); |
| } |
| if (strcmp (getenv ("PATH"), secure_getenv ("PATH")) != 0) |
| { |
| printf ("PATH mismatch (%s, %s)\n", |
| getenv ("PATH"), secure_getenv ("PATH")); |
| 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); |
| } |
| |
| static void |
| 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); |
| } |
| if (getenv ("PATH") == NULL) |
| { |
| printf ("PATH variable not present\n"); |
| exit (3); |
| } |
| if (secure_getenv ("PATH") != NULL) |
| { |
| printf ("PATH variable not filtered out\n"); |
| exit (4); |
| } |
| exit (MAGIC_STATUS); |
| } |
| } |
| |
| #define PREPARE alternative_main |
| #include <support/test-driver.c> |