From dbc83657e290bdad3245259be80fb84cbe10304c Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Thu, 22 May 2025 14:36:37 +0200 Subject: [PATCH] Fix error reporting (false negatives) in SGID tests And simplify the interface of support_capture_subprogram_self_sgid. Use the existing framework for temporary directories (now with mode 0700) and directory/file deletion. Handle all execution errors within support_capture_subprogram_self_sgid. In particular, this includes test failures because the invoked program did not exit with exit status zero. Existing tests that expect exit status 42 are adjusted to use zero instead. In addition, fix callers not to call exit (0) with test failures pending (which may mask them, especially when running with --direct). Fixes commit 35fc356fa3b4f485bd3ba3114c9f774e5df7d3c2 ("elf: Fix subprocess status handling for tst-dlopen-sgid (bug 32987)"). Reviewed-by: Carlos O'Donell (cherry picked from commit 3a3fb2ed83f79100c116c824454095ecfb335ad7) --- elf/tst-dlopen-sgid.c | 8 +- elf/tst-env-setuid-tunables.c | 18 +---- elf/tst-env-setuid.c | 17 +---- stdlib/tst-secure-getenv.c | 9 +-- support/capture_subprocess.h | 10 ++- support/support_capture_subprocess.c | 106 ++++++--------------------- 6 files changed, 36 insertions(+), 132 deletions(-) diff --git a/elf/tst-dlopen-sgid.c b/elf/tst-dlopen-sgid.c index 5688b79f2e..8aec52e19f 100644 --- a/elf/tst-dlopen-sgid.c +++ b/elf/tst-dlopen-sgid.c @@ -70,13 +70,7 @@ do_test (void) free (libdir); - 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); + support_capture_subprogram_self_sgid (magic_argument); return 0; } diff --git a/elf/tst-env-setuid-tunables.c b/elf/tst-env-setuid-tunables.c index a47219047f..233eec7631 100644 --- a/elf/tst-env-setuid-tunables.c +++ b/elf/tst-env-setuid-tunables.c @@ -105,10 +105,7 @@ do_test (int argc, char **argv) if (ret != 0) exit (1); - - /* Special return code to make sure that the child executed all the way - through. */ - exit (42); + return 0; } else { @@ -127,18 +124,7 @@ do_test (int argc, char **argv) continue; } - int status = support_capture_subprogram_self_sgid (buf); - - /* Bail out early if unsupported. */ - if (WEXITSTATUS (status) == EXIT_UNSUPPORTED) - return EXIT_UNSUPPORTED; - - if (WEXITSTATUS (status) != 42) - { - printf (" [%d] child failed with status %d\n", i, - WEXITSTATUS (status)); - support_record_failure (); - } + support_capture_subprogram_self_sgid (buf); } return 0; } diff --git a/elf/tst-env-setuid.c b/elf/tst-env-setuid.c index 59f2ffeb88..ee3f058468 100644 --- a/elf/tst-env-setuid.c +++ b/elf/tst-env-setuid.c @@ -147,10 +147,7 @@ do_test (int argc, char **argv) if (ret != 0) exit (1); - - /* Special return code to make sure that the child executed all the way - through. */ - exit (42); + return 0; } else { @@ -174,17 +171,7 @@ do_test (int argc, char **argv) free (profilepath); } - int status = support_capture_subprogram_self_sgid (SETGID_CHILD); - - if (WEXITSTATUS (status) == EXIT_UNSUPPORTED) - exit (EXIT_UNSUPPORTED); - - if (WEXITSTATUS (status) != 42) - { - printf (" child failed with status %d\n", - WEXITSTATUS (status)); - support_record_failure (); - } + support_capture_subprogram_self_sgid (SETGID_CHILD); return 0; } diff --git a/stdlib/tst-secure-getenv.c b/stdlib/tst-secure-getenv.c index cc26ed6d15..cefee58d46 100644 --- a/stdlib/tst-secure-getenv.c +++ b/stdlib/tst-secure-getenv.c @@ -57,13 +57,7 @@ do_test (void) exit (1); } - 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); + support_capture_subprogram_self_sgid (MAGIC_ARGUMENT); return 0; } @@ -82,6 +76,7 @@ alternative_main (int argc, char **argv) if (secure_getenv ("PATH") != NULL) FAIL_EXIT (4, "PATH variable not filtered out\n"); + support_record_failure_barrier (); exit (EXIT_SUCCESS); } } diff --git a/support/capture_subprocess.h b/support/capture_subprocess.h index 5406d9f6c0..57bb941e7d 100644 --- a/support/capture_subprocess.h +++ b/support/capture_subprocess.h @@ -42,10 +42,12 @@ struct support_capture_subprocess support_capture_subprocess struct support_capture_subprocess support_capture_subprogram (const char *file, char *const argv[], char *const envp[]); -/* 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 (const char *child_id); +/* Copy the running program into a setgid binary and run it with + CHILD_ID argument. If the program exits with a non-zero status, + exit with that exit status (or status 1 if the program did not exit + normally). If the test cannot be performed, exit with + EXIT_UNSUPPORTED. */ +void support_capture_subprogram_self_sgid (const char *child_id); /* Deallocate the subprocess data captured by support_capture_subprocess. */ diff --git a/support/support_capture_subprocess.c b/support/support_capture_subprocess.c index 1cb344eb04..cbc6951064 100644 --- a/support/support_capture_subprocess.c +++ b/support/support_capture_subprocess.c @@ -31,6 +31,7 @@ #include #include #include +#include #include static void @@ -113,105 +114,44 @@ support_capture_subprogram (const char *file, char *const argv[], /* 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 +static void copy_and_spawn_sgid (const char *child_id, gid_t gid) { - char *dirname = xasprintf ("%s/tst-tunables-setuid.%jd", - test_dir, (intmax_t) getpid ()); + char *dirname = support_create_temp_directory ("tst-glibc-sgid-"); char *execname = xasprintf ("%s/bin", dirname); - int infd = -1; - int outfd = -1; - int ret = 1, status = 1; + add_temp_file (execname); - TEST_VERIFY (mkdir (dirname, 0700) == 0); - if (support_record_failure_is_failed ()) - goto err; - - infd = open ("/proc/self/exe", O_RDONLY); - if (infd < 0) + if (access ("/proc/self/exe", R_OK) != 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; + support_copy_file ("/proc/self/exe", execname); - 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; - } - } + if (chown (execname, getuid (), gid) != 0) + FAIL_UNSUPPORTED ("cannot change group of \"%s\" to %jd: %m", + execname, (intmax_t) gid); - bool chowned = false; - TEST_VERIFY ((chowned = fchown (outfd, getuid (), gid) == 0) - || errno == EPERM); - if (support_record_failure_is_failed ()) - goto err; - else if (!chowned) - { - ret = 77; - 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; + if (chmod (execname, 02750) != 0) + FAIL_UNSUPPORTED ("cannot make \"%s\" SGID: %m ", execname); /* 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; - infd = outfd = -1; char * const args[] = {execname, (char *) child_id, NULL}; + int status = support_subprogram_wait (args[0], args); - status = support_subprogram_wait (args[0], args); + free (execname); + free (dirname); -err: - if (outfd >= 0) - close (outfd); - if (infd >= 0) - close (infd); - if (execname != NULL) + if (WIFEXITED (status)) { - unlink (execname); - free (execname); + if (WEXITSTATUS (status) == 0) + return; + else + exit (WEXITSTATUS (status)); } - if (dirname != NULL) - { - rmdir (dirname); - free (dirname); - } - - if (ret == 77) - FAIL_UNSUPPORTED ("Failed to make sgid executable for test\n"); - if (ret != 0) - FAIL_EXIT1 ("Failed to make sgid executable for test\n"); - - return status; + else + FAIL_EXIT1 ("subprogram failed with status %d", status); } /* Returns true if a group with NAME has been found, and writes its @@ -253,7 +193,7 @@ find_sgid_group (gid_t *target, const char *name) return ok; } -int +void support_capture_subprogram_self_sgid (const char *child_id) { const int count = 64; @@ -288,7 +228,7 @@ support_capture_subprogram_self_sgid (const char *child_id) (intmax_t) getuid ()); } - return copy_and_spawn_sgid (child_id, target); + copy_and_spawn_sgid (child_id, target); } void