* [COMMITTED 2.29 2/6] support: Typo and formatting fixes
2021-04-14 5:41 [COMMITTED 2.29 1/6] support: Pass environ to child process Siddhesh Poyarekar
@ 2021-04-14 5:41 ` Siddhesh Poyarekar
2021-04-14 5:41 ` [COMMITTED 2.29 3/6] support: Add capability to fork an sgid child Siddhesh Poyarekar
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Siddhesh Poyarekar @ 2021-04-14 5:41 UTC (permalink / raw)
To: libc-stable
- Add a newline to the end of error messages in transfer().
- Fixed the name of support_subprocess_init().
(cherry picked from commit 95c68080a3ded882789b1629f872c3ad531efda0)
---
support/support_capture_subprocess.c | 2 +-
support/support_subprocess.c | 6 +++---
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/support/support_capture_subprocess.c b/support/support_capture_subprocess.c
index 948ce5a0c6..ceb98616c2 100644
--- a/support/support_capture_subprocess.c
+++ b/support/support_capture_subprocess.c
@@ -36,7 +36,7 @@ transfer (const char *what, struct pollfd *pfd, struct xmemstream *stream)
if (ret < 0)
{
support_record_failure ();
- printf ("error: reading from subprocess %s: %m", what);
+ printf ("error: reading from subprocess %s: %m\n", what);
pfd->events = 0;
pfd->revents = 0;
}
diff --git a/support/support_subprocess.c b/support/support_subprocess.c
index 9e02ed747a..ae03c4b473 100644
--- a/support/support_subprocess.c
+++ b/support/support_subprocess.c
@@ -27,7 +27,7 @@
#include <support/subprocess.h>
static struct support_subprocess
-support_suprocess_init (void)
+support_subprocess_init (void)
{
struct support_subprocess result;
@@ -48,7 +48,7 @@ support_suprocess_init (void)
struct support_subprocess
support_subprocess (void (*callback) (void *), void *closure)
{
- struct support_subprocess result = support_suprocess_init ();
+ struct support_subprocess result = support_subprocess_init ();
result.pid = xfork ();
if (result.pid == 0)
@@ -71,7 +71,7 @@ support_subprocess (void (*callback) (void *), void *closure)
struct support_subprocess
support_subprogram (const char *file, char *const argv[])
{
- struct support_subprocess result = support_suprocess_init ();
+ struct support_subprocess result = support_subprocess_init ();
posix_spawn_file_actions_t fa;
/* posix_spawn_file_actions_init does not fail. */
--
2.29.2
^ permalink raw reply [flat|nested] 6+ messages in thread* [COMMITTED 2.29 3/6] support: Add capability to fork an sgid child
2021-04-14 5:41 [COMMITTED 2.29 1/6] support: Pass environ to child process Siddhesh Poyarekar
2021-04-14 5:41 ` [COMMITTED 2.29 2/6] support: Typo and formatting fixes Siddhesh Poyarekar
@ 2021-04-14 5:41 ` Siddhesh Poyarekar
2021-04-14 5:41 ` [COMMITTED 2.29 4/6] tst-env-setuid: Use support_capture_subprogram_self_sgid Siddhesh Poyarekar
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Siddhesh Poyarekar @ 2021-04-14 5:41 UTC (permalink / raw)
To: libc-stable; +Cc: Carlos O'Donell
Add a new function support_capture_subprogram_self_sgid that spawns an
sgid child of the running program with its own image and returns the
exit code of the child process. This functionality is used by at
least three tests in the testsuite at the moment, so it makes sense to
consolidate.
There is also a new function support_subprogram_wait which should
provide simple system() like functionality that does not set up file
actions. This is useful in cases where only the return code of the
spawned subprocess is interesting.
This patch also ports tst-secure-getenv to this new function. A
subsequent patch will port other tests. This also brings an important
change to tst-secure-getenv behaviour. Now instead of succeeding, the
test fails as UNSUPPORTED if it is unable to spawn a setgid child,
which is how it should have been in the first place.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 716a3bdc41b2b4b864dc64475015ba51e35e1273)
---
stdlib/tst-secure-getenv.c | 188 +++------------------------
support/capture_subprocess.h | 6 +
support/subprocess.h | 5 +
support/support_capture_subprocess.c | 126 ++++++++++++++++++
support/support_subprocess.c | 13 ++
5 files changed, 168 insertions(+), 170 deletions(-)
diff --git a/stdlib/tst-secure-getenv.c b/stdlib/tst-secure-getenv.c
index 74580b889a..ab793ae4f8 100644
--- a/stdlib/tst-secure-getenv.c
+++ b/stdlib/tst-secure-getenv.c
@@ -30,156 +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)
-{
- 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 2832cfc635..e42a84e70e 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 ceb98616c2..492b76d114 100644
--- a/support/support_capture_subprocess.c
+++ b/support/support_capture_subprocess.c
@@ -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 +105,129 @@ 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)
{
--
2.29.2
^ permalink raw reply [flat|nested] 6+ messages in thread* [COMMITTED 2.29 4/6] tst-env-setuid: Use support_capture_subprogram_self_sgid
2021-04-14 5:41 [COMMITTED 2.29 1/6] support: Pass environ to child process Siddhesh Poyarekar
2021-04-14 5:41 ` [COMMITTED 2.29 2/6] support: Typo and formatting fixes Siddhesh Poyarekar
2021-04-14 5:41 ` [COMMITTED 2.29 3/6] support: Add capability to fork an sgid child Siddhesh Poyarekar
@ 2021-04-14 5:41 ` Siddhesh Poyarekar
2021-04-14 5:41 ` [COMMITTED 2.29 5/6] Enhance setuid-tunables test Siddhesh Poyarekar
2021-04-14 5:41 ` [COMMITTED 2.29 6/6] Fix SXID_ERASE behavior in setuid programs (BZ #27471) Siddhesh Poyarekar
4 siblings, 0 replies; 6+ messages in thread
From: Siddhesh Poyarekar @ 2021-04-14 5:41 UTC (permalink / raw)
To: libc-stable; +Cc: Carlos O'Donell
Use the support_capture_subprogram_self_sgid to spawn an sgid child.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit ca335281068a1ed549a75ee64f90a8310755956f)
---
elf/tst-env-setuid.c | 197 +++----------------------------------------
1 file changed, 14 insertions(+), 183 deletions(-)
diff --git a/elf/tst-env-setuid.c b/elf/tst-env-setuid.c
index a080d2fa1c..2350976f8c 100644
--- a/elf/tst-env-setuid.c
+++ b/elf/tst-env-setuid.c
@@ -29,173 +29,12 @@
#include <sys/wait.h>
#include <unistd.h>
+#include <support/check.h>
#include <support/support.h>
#include <support/test-driver.h>
+#include <support/capture_subprocess.h>
static char SETGID_CHILD[] = "setgid-child";
-#define CHILD_STATUS 42
-
-/* 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;
-}
-
-/* Spawn and execute a program and verify that it returns the CHILD_STATUS. */
-static pid_t
-do_execve (char **args)
-{
- pid_t kid = vfork ();
-
- if (kid < 0)
- {
- printf ("vfork: %m\n");
- return -1;
- }
-
- if (kid == 0)
- {
- /* Child process. */
- execve (args[0], args, environ);
- _exit (-errno);
- }
-
- if (kid < 0)
- return 1;
-
- int status;
-
- if (waitpid (kid, &status, 0) < 0)
- {
- printf ("waitpid: %m\n");
- return 1;
- }
-
- if (WEXITSTATUS (status) == EXIT_UNSUPPORTED)
- return EXIT_UNSUPPORTED;
-
- if (!WIFEXITED (status) || WEXITSTATUS (status) != CHILD_STATUS)
- {
- printf ("Unexpected exit status %d from child process\n",
- WEXITSTATUS (status));
- return 1;
- }
- 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/tst-tunables-setuid.%jd",
- test_dir, (intmax_t) getpid ());
- char *execname = xasprintf ("%s/bin", dirname);
- int infd = -1;
- int outfd = -1;
- int ret = 0;
- 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;
- }
-
- char *args[] = {execname, SETGID_CHILD, NULL};
-
- ret = do_execve (args);
-
-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;
-}
#ifndef test_child
static int
@@ -256,40 +95,32 @@ do_test (int argc, char **argv)
if (argc == 2 && strcmp (argv[1], SETGID_CHILD) == 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 (EXIT_UNSUPPORTED);
- }
+ /* This can happen if the file system is mounted nosuid. */
+ FAIL_UNSUPPORTED ("SGID failed: GID and EGID match (%jd)\n",
+ (intmax_t) getgid ());
int ret = test_child ();
if (ret != 0)
exit (1);
- exit (CHILD_STATUS);
+ exit (EXIT_SUCCESS);
}
else
{
if (test_parent () != 0)
exit (1);
- /* Try running a setgid program. */
- 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);
- }
+ int status = support_capture_subprogram_self_sgid (SETGID_CHILD);
- return run_executable_sgid (target);
- }
+ if (WEXITSTATUS (status) == EXIT_UNSUPPORTED)
+ return EXIT_UNSUPPORTED;
+
+ if (!WIFEXITED (status))
+ FAIL_EXIT1 ("Unexpected exit status %d from child process\n", status);
- /* Something went wrong and our argv was corrupted. */
- _exit (1);
+ return 0;
+ }
}
#define TEST_FUNCTION_ARGV do_test
--
2.29.2
^ permalink raw reply [flat|nested] 6+ messages in thread* [COMMITTED 2.29 5/6] Enhance setuid-tunables test
2021-04-14 5:41 [COMMITTED 2.29 1/6] support: Pass environ to child process Siddhesh Poyarekar
` (2 preceding siblings ...)
2021-04-14 5:41 ` [COMMITTED 2.29 4/6] tst-env-setuid: Use support_capture_subprogram_self_sgid Siddhesh Poyarekar
@ 2021-04-14 5:41 ` Siddhesh Poyarekar
2021-04-14 5:41 ` [COMMITTED 2.29 6/6] Fix SXID_ERASE behavior in setuid programs (BZ #27471) Siddhesh Poyarekar
4 siblings, 0 replies; 6+ messages in thread
From: Siddhesh Poyarekar @ 2021-04-14 5:41 UTC (permalink / raw)
To: libc-stable; +Cc: Carlos O'Donell
Instead of passing GLIBC_TUNABLES via the environment, pass the
environment variable from parent to child. This allows us to test
multiple variables to ensure better coverage.
The test list currently only includes the case that's already being
tested. More tests will be added later.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 061fe3f8add46a89b7453e87eabb9c4695005ced)
---
elf/Makefile | 2 -
elf/tst-env-setuid-tunables.c | 90 +++++++++++++++++++++++++++--------
2 files changed, 69 insertions(+), 23 deletions(-)
diff --git a/elf/Makefile b/elf/Makefile
index 70b9d368e3..ea3a160024 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -1465,8 +1465,6 @@ $(objpfx)tst-nodelete-dlclose.out: $(objpfx)tst-nodelete-dlclose-dso.so \
tst-env-setuid-ENV = MALLOC_CHECK_=2 MALLOC_MMAP_THRESHOLD_=4096 \
LD_HWCAP_MASK=0x1
-tst-env-setuid-tunables-ENV = \
- GLIBC_TUNABLES=glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096
$(objpfx)tst-debug1: $(libdl)
$(objpfx)tst-debug1.out: $(objpfx)tst-debug1mod1.so
diff --git a/elf/tst-env-setuid-tunables.c b/elf/tst-env-setuid-tunables.c
index e92e9f5fbf..4681a60494 100644
--- a/elf/tst-env-setuid-tunables.c
+++ b/elf/tst-env-setuid-tunables.c
@@ -25,35 +25,50 @@
#include "config.h"
#undef _LIBC
-#define test_parent test_parent_tunables
-#define test_child test_child_tunables
-
-static int test_child_tunables (void);
-static int test_parent_tunables (void);
-
-#include "tst-env-setuid.c"
+#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 <intprops.h>
+#include <array_length.h>
+
+#include <support/check.h>
+#include <support/support.h>
+#include <support/test-driver.h>
+#include <support/capture_subprocess.h>
+
+const char *teststrings[] =
+{
+ "glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096",
+};
-#define CHILD_VALSTRING_VALUE "glibc.malloc.mmap_threshold=4096"
-#define PARENT_VALSTRING_VALUE \
- "glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096"
+const char *resultstrings[] =
+{
+ "glibc.malloc.mmap_threshold=4096",
+};
static int
-test_child_tunables (void)
+test_child (int off)
{
const char *val = getenv ("GLIBC_TUNABLES");
#if HAVE_TUNABLES
- if (val != NULL && strcmp (val, CHILD_VALSTRING_VALUE) == 0)
+ if (val != NULL && strcmp (val, resultstrings[off]) == 0)
return 0;
if (val != NULL)
- printf ("Unexpected GLIBC_TUNABLES VALUE %s\n", val);
+ printf ("[%d] Unexpected GLIBC_TUNABLES VALUE %s\n", off, val);
return 1;
#else
if (val != NULL)
{
- printf ("GLIBC_TUNABLES not cleared\n");
+ printf ("[%d] GLIBC_TUNABLES not cleared\n", off);
return 1;
}
return 0;
@@ -61,15 +76,48 @@ test_child_tunables (void)
}
static int
-test_parent_tunables (void)
+do_test (int argc, char **argv)
{
- const char *val = getenv ("GLIBC_TUNABLES");
+ /* Setgid child process. */
+ if (argc == 2)
+ {
+ if (getgid () == getegid ())
+ /* This can happen if the file system is mounted nosuid. */
+ FAIL_UNSUPPORTED ("SGID failed: GID and EGID match (%jd)\n",
+ (intmax_t) getgid ());
- if (val != NULL && strcmp (val, PARENT_VALSTRING_VALUE) == 0)
- return 0;
+ int ret = test_child (atoi (argv[1]));
- if (val != NULL)
- printf ("Unexpected GLIBC_TUNABLES VALUE %s\n", val);
+ if (ret != 0)
+ exit (1);
- return 1;
+ exit (EXIT_SUCCESS);
+ }
+ else
+ {
+ int ret = 0;
+
+ /* Spawn tests. */
+ for (int i = 0; i < array_length (teststrings); i++)
+ {
+ char buf[INT_BUFSIZE_BOUND (int)];
+
+ printf ("Spawned test for %s (%d)\n", teststrings[i], i);
+ snprintf (buf, sizeof (buf), "%d\n", i);
+ if (setenv ("GLIBC_TUNABLES", teststrings[i], 1) != 0)
+ exit (1);
+
+ int status = support_capture_subprogram_self_sgid (buf);
+
+ /* Bail out early if unsupported. */
+ if (WEXITSTATUS (status) == EXIT_UNSUPPORTED)
+ return EXIT_UNSUPPORTED;
+
+ ret |= status;
+ }
+ return ret;
+ }
}
+
+#define TEST_FUNCTION_ARGV do_test
+#include <support/test-driver.c>
--
2.29.2
^ permalink raw reply [flat|nested] 6+ messages in thread* [COMMITTED 2.29 6/6] Fix SXID_ERASE behavior in setuid programs (BZ #27471)
2021-04-14 5:41 [COMMITTED 2.29 1/6] support: Pass environ to child process Siddhesh Poyarekar
` (3 preceding siblings ...)
2021-04-14 5:41 ` [COMMITTED 2.29 5/6] Enhance setuid-tunables test Siddhesh Poyarekar
@ 2021-04-14 5:41 ` Siddhesh Poyarekar
4 siblings, 0 replies; 6+ messages in thread
From: Siddhesh Poyarekar @ 2021-04-14 5:41 UTC (permalink / raw)
To: libc-stable; +Cc: Carlos O'Donell
When parse_tunables tries to erase a tunable marked as SXID_ERASE for
setuid programs, it ends up setting the envvar string iterator
incorrectly, because of which it may parse the next tunable
incorrectly. Given that currently the implementation allows malformed
and unrecognized tunables pass through, it may even allow SXID_ERASE
tunables to go through.
This change revamps the SXID_ERASE implementation so that:
- Only valid tunables are written back to the tunestr string, because
of which children of SXID programs will only inherit a clean list of
identified tunables that are not SXID_ERASE.
- Unrecognized tunables get scrubbed off from the environment and
subsequently from the child environment.
- This has the side-effect that a tunable that is not identified by
the setxid binary, will not be passed on to a non-setxid child even
if the child could have identified that tunable. This may break
applications that expect this behaviour but expecting such tunables
to cross the SXID boundary is wrong.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 2ed18c5b534d9e92fc006202a5af0df6b72e7aca)
---
elf/dl-tunables.c | 56 ++++++++++++++++-------------------
elf/tst-env-setuid-tunables.c | 26 ++++++++++++++++
2 files changed, 52 insertions(+), 30 deletions(-)
diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c
index 542e837832..87d21f2e8e 100644
--- a/elf/dl-tunables.c
+++ b/elf/dl-tunables.c
@@ -178,6 +178,7 @@ parse_tunables (char *tunestr, char *valstring)
return;
char *p = tunestr;
+ size_t off = 0;
while (true)
{
@@ -191,7 +192,11 @@ parse_tunables (char *tunestr, char *valstring)
/* If we reach the end of the string before getting a valid name-value
pair, bail out. */
if (p[len] == '\0')
- return;
+ {
+ if (__libc_enable_secure)
+ tunestr[off] = '\0';
+ return;
+ }
/* We did not find a valid name-value pair before encountering the
colon. */
@@ -217,35 +222,28 @@ parse_tunables (char *tunestr, char *valstring)
if (tunable_is_name (cur->name, name))
{
- /* If we are in a secure context (AT_SECURE) then ignore the tunable
- unless it is explicitly marked as secure. Tunable values take
- precendence over their envvar aliases. */
+ /* If we are in a secure context (AT_SECURE) then ignore the
+ tunable unless it is explicitly marked as secure. Tunable
+ values take precedence over their envvar aliases. We write
+ the tunables that are not SXID_ERASE back to TUNESTR, thus
+ dropping all SXID_ERASE tunables and any invalid or
+ unrecognized tunables. */
if (__libc_enable_secure)
{
- if (cur->security_level == TUNABLE_SECLEVEL_SXID_ERASE)
+ if (cur->security_level != TUNABLE_SECLEVEL_SXID_ERASE)
{
- if (p[len] == '\0')
- {
- /* Last tunable in the valstring. Null-terminate and
- return. */
- *name = '\0';
- return;
- }
- else
- {
- /* Remove the current tunable from the string. We do
- this by overwriting the string starting from NAME
- (which is where the current tunable begins) with
- the remainder of the string. We then have P point
- to NAME so that we continue in the correct
- position in the valstring. */
- char *q = &p[len + 1];
- p = name;
- while (*q != '\0')
- *name++ = *q++;
- name[0] = '\0';
- len = 0;
- }
+ if (off > 0)
+ tunestr[off++] = ':';
+
+ const char *n = cur->name;
+
+ while (*n != '\0')
+ tunestr[off++] = *n++;
+
+ tunestr[off++] = '=';
+
+ for (size_t j = 0; j < len; j++)
+ tunestr[off++] = value[j];
}
if (cur->security_level != TUNABLE_SECLEVEL_NONE)
@@ -258,9 +256,7 @@ parse_tunables (char *tunestr, char *valstring)
}
}
- if (p[len] == '\0')
- return;
- else
+ if (p[len] != '\0')
p += len + 1;
}
}
diff --git a/elf/tst-env-setuid-tunables.c b/elf/tst-env-setuid-tunables.c
index 4681a60494..0e9aedeb2e 100644
--- a/elf/tst-env-setuid-tunables.c
+++ b/elf/tst-env-setuid-tunables.c
@@ -45,11 +45,37 @@
const char *teststrings[] =
{
"glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096",
+ "glibc.malloc.check=2:glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096",
+ "glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096:glibc.malloc.check=2",
+ "glibc.malloc.perturb=0x800",
+ "glibc.malloc.perturb=0x800:glibc.malloc.mmap_threshold=4096",
+ "glibc.malloc.perturb=0x800:not_valid.malloc.check=2:glibc.malloc.mmap_threshold=4096",
+ "glibc.not_valid.check=2:glibc.malloc.mmap_threshold=4096",
+ "not_valid.malloc.check=2:glibc.malloc.mmap_threshold=4096",
+ "glibc.malloc.garbage=2:glibc.maoc.mmap_threshold=4096:glibc.malloc.check=2",
+ "glibc.malloc.check=4:glibc.malloc.garbage=2:glibc.maoc.mmap_threshold=4096",
+ ":glibc.malloc.garbage=2:glibc.malloc.check=1",
+ "glibc.malloc.check=1:glibc.malloc.check=2",
+ "not_valid.malloc.check=2",
+ "glibc.not_valid.check=2",
};
const char *resultstrings[] =
{
"glibc.malloc.mmap_threshold=4096",
+ "glibc.malloc.mmap_threshold=4096",
+ "glibc.malloc.mmap_threshold=4096",
+ "glibc.malloc.perturb=0x800",
+ "glibc.malloc.perturb=0x800:glibc.malloc.mmap_threshold=4096",
+ "glibc.malloc.perturb=0x800:glibc.malloc.mmap_threshold=4096",
+ "glibc.malloc.mmap_threshold=4096",
+ "glibc.malloc.mmap_threshold=4096",
+ "",
+ "",
+ "",
+ "",
+ "",
+ "",
};
static int
--
2.29.2
^ permalink raw reply [flat|nested] 6+ messages in thread