@@ -30,167 +30,12 @@
#include <sys/wait.h>
#include <unistd.h>
+#include <support/check.h>
#include <support/support.h>
+#include <support/capture_subprocess.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)
-{
- int count = getgroups (0, NULL);
- if (count < 0)
- {
- printf ("getgroups: %m\n");
- exit (1);
- }
- gid_t *groups;
- groups = xcalloc (count, sizeof (*groups));
- int ret = getgroups (count, groups);
- if (ret < 0)
- {
- printf ("getgroups: %m\n");
- exit (1);
- }
- gid_t current = getgid ();
- gid_t not_current = 0;
- for (int i = 0; i < ret; ++i)
- {
- if (groups[i] != current)
- {
- not_current = groups[i];
- break;
- }
- }
- free (groups);
- return not_current;
-}
-
-
-/* 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)
@@ -212,15 +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
@@ -229,23 +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);
}
}
@@ -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 *);
@@ -54,6 +54,18 @@ __BEGIN_DECLS
support_test_verify_impl (__FILE__, __LINE__, #expr); \
})
+/* Record a test failure and jump to LABEL if EXPR evaluates to false. */
+#define TEST_VERIFY_GOTO(expr, label) \
+ ({ \
+ if ((expr)) \
+ ; \
+ else \
+ { \
+ support_test_verify_impl (__FILE__, __LINE__, #expr); \
+ goto label; \
+ } \
+ })
+
/* Record a test failure and exit if EXPR evaluates to false. */
#define TEST_VERIFY_EXIT(expr) \
({ \
@@ -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);
@@ -20,11 +20,14 @@
#include <support/capture_subprocess.h>
#include <errno.h>
+#include <fcntl.h>
#include <stdlib.h>
#include <support/check.h>
#include <support/xunistd.h>
#include <support/xsocket.h>
#include <support/xspawn.h>
+#include <support/support.h>
+#include <support/test-driver.h>
static void
transfer (const char *what, struct pollfd *pfd, struct xmemstream *stream)
@@ -102,6 +105,117 @@ 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_GOTO (mkdir (dirname, 0700) >= 0, 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_GOTO (outfd >= 0, err);
+
+ char buf[4096];
+ for (;;)
+ {
+ ssize_t rdcount = read (infd, buf, sizeof (buf));
+ TEST_VERIFY_GOTO (rdcount >= 0, 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_GOTO (wrcount > 0, err);
+ p += wrcount;
+ }
+ }
+ int goto_ret = fchown (outfd, getuid (), gid);
+ TEST_VERIFY_GOTO (goto_ret == 0, err);
+ goto_ret = fchmod (outfd, 02750);
+ TEST_VERIFY_GOTO (goto_ret == 0, err);
+ goto_ret = close (outfd);
+ TEST_VERIFY_GOTO (goto_ret == 0, err);
+ goto_ret = close (infd);
+ TEST_VERIFY_GOTO (goto_ret == 0, 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)
{
@@ -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)
{