diff mbox series

[v3] syscalls/prctl06: New test for prctl() with PR_{SET, GET}_NO_NEW_PRIVS

Message ID 1562907197-2322-1-git-send-email-xuyang2018.jy@cn.fujitsu.com
State Superseded
Headers show
Series [v3] syscalls/prctl06: New test for prctl() with PR_{SET, GET}_NO_NEW_PRIVS | expand

Commit Message

Yang Xu July 12, 2019, 4:53 a.m. UTC 
Signed-off-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
---
 include/lapi/prctl.h                          |   5 +
 runtest/syscalls                              |   1 +
 testcases/kernel/syscalls/prctl/.gitignore    |   2 +
 testcases/kernel/syscalls/prctl/prctl06.c     | 165 ++++++++++++++++++
 .../kernel/syscalls/prctl/prctl06_execve.c    |  52 ++++++
 5 files changed, 225 insertions(+)
 create mode 100644 testcases/kernel/syscalls/prctl/prctl06.c
 create mode 100644 testcases/kernel/syscalls/prctl/prctl06_execve.c

Comments

Cyril Hrubis July 15, 2019, 3:49 p.m. UTC | #1 
Hi!
> +static uid_t nobody_uid;
> +static gid_t nobody_gid;
> +static int flag = 1;
> +
> +static void check_proc_field(int val, char *name)
> +{
> +	int field = 0;
> +	char path[50];
> +
> +	strcpy(path, "/proc/self/status");

Can't we just define PROC_STATUS "/proc/self/status" and use that
instead of copying bytes around at runtime?

> +	TEST(FILE_LINES_SCANF(path, "NoNewPrivs:%d", &field));
> +	if (TST_RET == 1) {
> +		tst_res(TCONF,
> +			"%s doesn't support NoNewPrivs field", path);
> +		flag = 0;
> +		return;
> +	}
> +	if (val == field)
> +		tst_res(TPASS, "%s %s NoNewPrivs field expected %d got %d",
> +			name, path, val, field);
> +	else
> +		tst_res(TFAIL, "%s %s NoNewPrivs field expected %d got %d",
> +			name, path, val, field);
> +}
> +
> +static void check_no_new_privs(int val, char *name)
> +{
> +	TEST(prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0));
> +	if (TST_RET == val)
> +		tst_res(TPASS,
> +			"%s prctl(PR_GET_NO_NEW_PRIVS) expected %d got %d",
> +			name, val, val);
> +	else
> +		tst_res(TFAIL,
> +			"%s prctl(PR_GET_NO_NEW_PRIVS) expected %d got %ld",
> +			name, val, TST_RET);
> +	if (flag)
> +		check_proc_field(val, name);
> +}
> +
> +static void do_prctl(void)
> +{
> +	char ipc_env_var[1024];
> +	char *const argv[] = {"prctl06_execve", "parent process", NULL};
> +	char *const childargv[] = {"prctl06_execve", "child process", NULL};
> +	char *const envp[] = {ipc_env_var, NULL };
> +	int childpid;
> +
> +	check_no_new_privs(0, "parent");
> +
> +	TEST(prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
> +	if (TST_RET == -1) {
> +		tst_res(TFAIL | TTERRNO, "prctl(PR_SET_NO_NEW_PRIVS) failed");
> +		return;
> +	}
> +	tst_res(TPASS, "prctl(PR_SET_NO_NEW_PRIVS) succeeded");
> +
> +	SAFE_SETGID(nobody_gid);
> +	SAFE_SETUID(nobody_uid);
> +
> +	sprintf(ipc_env_var, IPC_ENV_VAR "=%s", getenv(IPC_ENV_VAR));
> +
> +	childpid = SAFE_FORK();
> +	if (childpid == 0) {
> +		check_no_new_privs(1, "child");
> +		execve("prctl06_execve", childargv, envp);
> +		tst_brk(TFAIL | TTERRNO,
> +			"child process failed to execute prctl_execve");
> +
> +	} else {
> +		tst_reap_children();
> +		check_no_new_privs(1, "parent");
> +		execve("prctl06_execve", argv, envp);
> +		tst_brk(TFAIL | TTERRNO,
> +			"parent process failed to execute prctl_execve");
> +	}
> +}
> +
> +static void verify_prctl(void)
> +{
> +	int pid;
> +
> +	pid = SAFE_FORK();
> +	if (pid == 0) {
> +		do_prctl();
> +		exit(0);
> +	}
> +}
> +
> +static void setup(void)
> +{
> +	struct passwd *pw;
> +
> +	pw = SAFE_GETPWNAM("nobody");
> +	nobody_uid = pw->pw_uid;
> +	nobody_gid = pw->pw_gid;
> +
> +	SAFE_CP(TESTBIN, TEST_REL_BIN_DIR);
> +	SAFE_CHMOD("prctl06_execve", SUID_MODE);
> +	SAFE_CHOWN("prctl06_execve", 0, 0);

You are actually changing and executing the wrong file here. You are
working directly with the file in the test temporary directory and not
with the file that has been copied over to the mount point.

I guess that we should define BIN_PATH and use it here and also for the
execve() above.

> +	TEST(prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0));
> +	if (TST_RET == 0) {
> +		tst_res(TINFO, "kernel supports PR_GET/SET_NO_NEW_PRIVS");
> +		return;
> +	}
> +
> +	if (TST_ERR == EINVAL)
> +		tst_brk(TCONF,
> +			"kernel doesn't support PR_GET/SET_NO_NEW_PRIVS");
> +
> +	tst_brk(TBROK | TTERRNO,
> +		"current environment doesn't permit PR_GET/SET_NO_NEW_PRIVS");
> +}
> +
> +static const char *const resfile[] = {
> +	TESTBIN,
> +	NULL,
> +};
> +
> +static struct tst_test test = {
> +	.resource_files = resfile,
> +	.setup = setup,
> +	.test_all = verify_prctl,
> +	.forks_child = 1,
> +	.needs_root = 1,
> +	.mount_device = 1,
> +	.mntpoint = MNTPOINT,
> +	.child_needs_reinit = 1,
> +};
> diff --git a/testcases/kernel/syscalls/prctl/prctl06_execve.c b/testcases/kernel/syscalls/prctl/prctl06_execve.c
> new file mode 100644
> index 000000000..92e218020
> --- /dev/null
> +++ b/testcases/kernel/syscalls/prctl/prctl06_execve.c
> @@ -0,0 +1,52 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2019 FUJITSU LIMITED. All rights reserved.
> + * Author: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
> + *
> + * dummy program which is used by prctl06 testcase
> + */
> +#define TST_NO_DEFAULT_MAIN
> +#include <stdlib.h>
> +#include <sys/types.h>
> +#include <unistd.h>
> +#include <errno.h>
> +#include <pwd.h>
> +#include <stdio.h>
> +#include <string.h>
> +#include "tst_test.h"
> +
> +int main(int argc, char **argv)
> +{
> +	char path[50];
> +	struct passwd *pw;
> +
> +	pw = SAFE_GETPWNAM("nobody");
> +
> +	tst_reinit();
> +	if (argc != 2)
> +		tst_brk(TFAIL, "argc is %d, expected 2", argc);
> +
> +	strcpy(path, "/proc/self/status");

Here as well, can we use a macro instead?

> +	TEST(getegid());
> +	if (TST_RET == 0)
> +		tst_res(TFAIL,
> +			"%s getegid() returns 0 unexpectedly, it gains root privileges",
> +			argv[1]);
> +	if (TST_RET == pw->pw_gid)
> +		tst_res(TPASS,
> +			"%s getegid() returns nobody, it doesn't gain root privileges",
> +			argv[1]);
> +
> +	TEST(geteuid());
> +	if (TST_RET == 0)
> +		tst_res(TFAIL,
> +			"%s geteuid() returns 0 unexpectedly, it gains root privileges",
> +			argv[1]);
> +	if (TST_RET == pw->pw_uid)
> +		tst_res(TPASS,
> +			"%s geteuid() returns nobody, it doesn't gain root privileges",
> +			argv[1]);
> +
> +	return 0;
> +}

The rest looks good.
Yang Xu July 16, 2019, 5:32 a.m. UTC | #2 
> Hi!
>> +static uid_t nobody_uid;
>> +static gid_t nobody_gid;
>> +static int flag = 1;
>> +
>> +static void check_proc_field(int val, char *name)
>> +{
>> +	int field = 0;
>> +	char path[50];
>> +
>> +	strcpy(path, "/proc/self/status");
> Can't we just define PROC_STATUS "/proc/self/status" and use that
> instead of copying bytes around at runtime?
>
Hi

Yes. I move PROC_STATUS and check functions into prctl06.h because we also need to check field after execve.
Please see my v4 patch.

>> +	TEST(FILE_LINES_SCANF(path, "NoNewPrivs:%d",&field));
>> +	if (TST_RET == 1) {
>> +		tst_res(TCONF,
>> +			"%s doesn't support NoNewPrivs field", path);
>> +		flag = 0;
>> +		return;
>> +	}
>> +	if (val == field)
>> +		tst_res(TPASS, "%s %s NoNewPrivs field expected %d got %d",
>> +			name, path, val, field);
>> +	else
>> +		tst_res(TFAIL, "%s %s NoNewPrivs field expected %d got %d",
>> +			name, path, val, field);
>> +}
>> +
>> +static void check_no_new_privs(int val, char *name)
>> +{
>> +	TEST(prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0));
>> +	if (TST_RET == val)
>> +		tst_res(TPASS,
>> +			"%s prctl(PR_GET_NO_NEW_PRIVS) expected %d got %d",
>> +			name, val, val);
>> +	else
>> +		tst_res(TFAIL,
>> +			"%s prctl(PR_GET_NO_NEW_PRIVS) expected %d got %ld",
>> +			name, val, TST_RET);
>> +	if (flag)
>> +		check_proc_field(val, name);
>> +}
>> +
>> +static void do_prctl(void)
>> +{
>> +	char ipc_env_var[1024];
>> +	char *const argv[] = {"prctl06_execve", "parent process", NULL};
>> +	char *const childargv[] = {"prctl06_execve", "child process", NULL};
>> +	char *const envp[] = {ipc_env_var, NULL };
>> +	int childpid;
>> +
>> +	check_no_new_privs(0, "parent");
>> +
>> +	TEST(prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
>> +	if (TST_RET == -1) {
>> +		tst_res(TFAIL | TTERRNO, "prctl(PR_SET_NO_NEW_PRIVS) failed");
>> +		return;
>> +	}
>> +	tst_res(TPASS, "prctl(PR_SET_NO_NEW_PRIVS) succeeded");
>> +
>> +	SAFE_SETGID(nobody_gid);
>> +	SAFE_SETUID(nobody_uid);
>> +
>> +	sprintf(ipc_env_var, IPC_ENV_VAR "=%s", getenv(IPC_ENV_VAR));
>> +
>> +	childpid = SAFE_FORK();
>> +	if (childpid == 0) {
>> +		check_no_new_privs(1, "child");
>> +		execve("prctl06_execve", childargv, envp);
>> +		tst_brk(TFAIL | TTERRNO,
>> +			"child process failed to execute prctl_execve");
>> +
>> +	} else {
>> +		tst_reap_children();
>> +		check_no_new_privs(1, "parent");
>> +		execve("prctl06_execve", argv, envp);
>> +		tst_brk(TFAIL | TTERRNO,
>> +			"parent process failed to execute prctl_execve");
>> +	}
>> +}
>> +
>> +static void verify_prctl(void)
>> +{
>> +	int pid;
>> +
>> +	pid = SAFE_FORK();
>> +	if (pid == 0) {
>> +		do_prctl();
>> +		exit(0);
>> +	}
>> +}
>> +
>> +static void setup(void)
>> +{
>> +	struct passwd *pw;
>> +
>> +	pw = SAFE_GETPWNAM("nobody");
>> +	nobody_uid = pw->pw_uid;
>> +	nobody_gid = pw->pw_gid;
>> +
>> +	SAFE_CP(TESTBIN, TEST_REL_BIN_DIR);
>> +	SAFE_CHMOD("prctl06_execve", SUID_MODE);
>> +	SAFE_CHOWN("prctl06_execve", 0, 0);
> You are actually changing and executing the wrong file here. You are
> working directly with the file in the test temporary directory and not
> with the file that has been copied over to the mount point.
>
> I guess that we should define BIN_PATH and use it here and also for the
> execve() above.
Yes .

>> +	TEST(prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0));
>> +	if (TST_RET == 0) {
>> +		tst_res(TINFO, "kernel supports PR_GET/SET_NO_NEW_PRIVS");
>> +		return;
>> +	}
>> +
>> +	if (TST_ERR == EINVAL)
>> +		tst_brk(TCONF,
>> +			"kernel doesn't support PR_GET/SET_NO_NEW_PRIVS");
>> +
>> +	tst_brk(TBROK | TTERRNO,
>> +		"current environment doesn't permit PR_GET/SET_NO_NEW_PRIVS");
>> +}
>> +
>> +static const char *const resfile[] = {
>> +	TESTBIN,
>> +	NULL,
>> +};
>> +
>> +static struct tst_test test = {
>> +	.resource_files = resfile,
>> +	.setup = setup,
>> +	.test_all = verify_prctl,
>> +	.forks_child = 1,
>> +	.needs_root = 1,
>> +	.mount_device = 1,
>> +	.mntpoint = MNTPOINT,
>> +	.child_needs_reinit = 1,
>> +};
>> diff --git a/testcases/kernel/syscalls/prctl/prctl06_execve.c b/testcases/kernel/syscalls/prctl/prctl06_execve.c
>> new file mode 100644
>> index 000000000..92e218020
>> --- /dev/null
>> +++ b/testcases/kernel/syscalls/prctl/prctl06_execve.c
>> @@ -0,0 +1,52 @@
>> +// SPDX-License-Identifier: GPL-2.0-or-later
>> +/*
>> + * Copyright (c) 2019 FUJITSU LIMITED. All rights reserved.
>> + * Author: Yang Xu<xuyang2018.jy@cn.fujitsu.com>
>> + *
>> + * dummy program which is used by prctl06 testcase
>> + */
>> +#define TST_NO_DEFAULT_MAIN
>> +#include<stdlib.h>
>> +#include<sys/types.h>
>> +#include<unistd.h>
>> +#include<errno.h>
>> +#include<pwd.h>
>> +#include<stdio.h>
>> +#include<string.h>
>> +#include "tst_test.h"
>> +
>> +int main(int argc, char **argv)
>> +{
>> +	char path[50];
>> +	struct passwd *pw;
>> +
>> +	pw = SAFE_GETPWNAM("nobody");
>> +
>> +	tst_reinit();
>> +	if (argc != 2)
>> +		tst_brk(TFAIL, "argc is %d, expected 2", argc);
>> +
>> +	strcpy(path, "/proc/self/status");
> Here as well, can we use a macro instead?
Yes

>> +	TEST(getegid());
>> +	if (TST_RET == 0)
>> +		tst_res(TFAIL,
>> +			"%s getegid() returns 0 unexpectedly, it gains root privileges",
>> +			argv[1]);
>> +	if (TST_RET == pw->pw_gid)
>> +		tst_res(TPASS,
>> +			"%s getegid() returns nobody, it doesn't gain root privileges",
>> +			argv[1]);
>> +
>> +	TEST(geteuid());
>> +	if (TST_RET == 0)
>> +		tst_res(TFAIL,
>> +			"%s geteuid() returns 0 unexpectedly, it gains root privileges",
>> +			argv[1]);
>> +	if (TST_RET == pw->pw_uid)
>> +		tst_res(TPASS,
>> +			"%s geteuid() returns nobody, it doesn't gain root privileges",
>> +			argv[1]);
>> +
>> +	return 0;
>> +}
> The rest looks good.
>
diff mbox series

Patch

diff --git a/include/lapi/prctl.h b/include/lapi/prctl.h
index ad0b12bce..54b3da20f 100644
--- a/include/lapi/prctl.h
+++ b/include/lapi/prctl.h
@@ -24,4 +24,9 @@ 
 # define PR_GET_CHILD_SUBREAPER	37
 #endif
 
+#ifndef PR_SET_NO_NEW_PRIVS
+# define PR_SET_NO_NEW_PRIVS 38
+# define PR_GET_NO_NEW_PRIVS 39
+#endif
+
 #endif /* LAPI_PRCTL_H__ */
diff --git a/runtest/syscalls b/runtest/syscalls
index 42c200423..ef7af41b5 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -865,6 +865,7 @@  prctl02 prctl02
 prctl03 prctl03
 prctl04 prctl04
 prctl05 prctl05
+prctl06 prctl06
 
 pread01 pread01
 pread01_64 pread01_64
diff --git a/testcases/kernel/syscalls/prctl/.gitignore b/testcases/kernel/syscalls/prctl/.gitignore
index 9ecaf9854..ee994086f 100644
--- a/testcases/kernel/syscalls/prctl/.gitignore
+++ b/testcases/kernel/syscalls/prctl/.gitignore
@@ -3,3 +3,5 @@ 
 /prctl03
 /prctl04
 /prctl05
+/prctl06
+/prctl06_execve
diff --git a/testcases/kernel/syscalls/prctl/prctl06.c b/testcases/kernel/syscalls/prctl/prctl06.c
new file mode 100644
index 000000000..71160b1c1
--- /dev/null
+++ b/testcases/kernel/syscalls/prctl/prctl06.c
@@ -0,0 +1,165 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2019 FUJITSU LIMITED. All rights reserved.
+ * Author: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
+ *
+ * Test PR_GET_NO_NEW_PRIVS and PR_SET_NO_NEW_PRIVS of prctl(2).
+ *
+ * 1)Return the value of the no_new_privs bit for the calling thread.
+ *  A value of 0 indicates the regular execve(2) behavior.  A value of
+ *  1 indicates execve(2) will operate in the privilege-restricting mode.
+ * 2)With no_new_privs set to 1, diables privilege granting operations
+ *  at execve-time. For example, a process will not be able to execute a
+ *  setuid binary to change their uid or gid if this bit is set. The same
+ *  is true for file capabilities.
+ * 3)The setting of this bit is inherited by children created by fork(2).
+ *  We also check NoNewPrivs field in /proc/[pid]/status if it supports.
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/prctl.h>
+#include <pwd.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <sys/capability.h>
+#include <lapi/prctl.h>
+#include "tst_test.h"
+
+#define IPC_ENV_VAR        "LTP_IPC_PATH"
+#define MNTPOINT           "mntpoint"
+#define TESTBIN            "prctl06_execve"
+#define TEST_REL_BIN_DIR   MNTPOINT"/"
+#define SUID_MODE          (S_ISUID|S_ISGID|S_IXUSR|S_IXGRP|S_IXOTH)
+
+static uid_t nobody_uid;
+static gid_t nobody_gid;
+static int flag = 1;
+
+static void check_proc_field(int val, char *name)
+{
+	int field = 0;
+	char path[50];
+
+	strcpy(path, "/proc/self/status");
+	TEST(FILE_LINES_SCANF(path, "NoNewPrivs:%d", &field));
+	if (TST_RET == 1) {
+		tst_res(TCONF,
+			"%s doesn't support NoNewPrivs field", path);
+		flag = 0;
+		return;
+	}
+	if (val == field)
+		tst_res(TPASS, "%s %s NoNewPrivs field expected %d got %d",
+			name, path, val, field);
+	else
+		tst_res(TFAIL, "%s %s NoNewPrivs field expected %d got %d",
+			name, path, val, field);
+}
+
+static void check_no_new_privs(int val, char *name)
+{
+	TEST(prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0));
+	if (TST_RET == val)
+		tst_res(TPASS,
+			"%s prctl(PR_GET_NO_NEW_PRIVS) expected %d got %d",
+			name, val, val);
+	else
+		tst_res(TFAIL,
+			"%s prctl(PR_GET_NO_NEW_PRIVS) expected %d got %ld",
+			name, val, TST_RET);
+	if (flag)
+		check_proc_field(val, name);
+}
+
+static void do_prctl(void)
+{
+	char ipc_env_var[1024];
+	char *const argv[] = {"prctl06_execve", "parent process", NULL};
+	char *const childargv[] = {"prctl06_execve", "child process", NULL};
+	char *const envp[] = {ipc_env_var, NULL };
+	int childpid;
+
+	check_no_new_privs(0, "parent");
+
+	TEST(prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
+	if (TST_RET == -1) {
+		tst_res(TFAIL | TTERRNO, "prctl(PR_SET_NO_NEW_PRIVS) failed");
+		return;
+	}
+	tst_res(TPASS, "prctl(PR_SET_NO_NEW_PRIVS) succeeded");
+
+	SAFE_SETGID(nobody_gid);
+	SAFE_SETUID(nobody_uid);
+
+	sprintf(ipc_env_var, IPC_ENV_VAR "=%s", getenv(IPC_ENV_VAR));
+
+	childpid = SAFE_FORK();
+	if (childpid == 0) {
+		check_no_new_privs(1, "child");
+		execve("prctl06_execve", childargv, envp);
+		tst_brk(TFAIL | TTERRNO,
+			"child process failed to execute prctl_execve");
+
+	} else {
+		tst_reap_children();
+		check_no_new_privs(1, "parent");
+		execve("prctl06_execve", argv, envp);
+		tst_brk(TFAIL | TTERRNO,
+			"parent process failed to execute prctl_execve");
+	}
+}
+
+static void verify_prctl(void)
+{
+	int pid;
+
+	pid = SAFE_FORK();
+	if (pid == 0) {
+		do_prctl();
+		exit(0);
+	}
+}
+
+static void setup(void)
+{
+	struct passwd *pw;
+
+	pw = SAFE_GETPWNAM("nobody");
+	nobody_uid = pw->pw_uid;
+	nobody_gid = pw->pw_gid;
+
+	SAFE_CP(TESTBIN, TEST_REL_BIN_DIR);
+	SAFE_CHMOD("prctl06_execve", SUID_MODE);
+	SAFE_CHOWN("prctl06_execve", 0, 0);
+
+	TEST(prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0));
+	if (TST_RET == 0) {
+		tst_res(TINFO, "kernel supports PR_GET/SET_NO_NEW_PRIVS");
+		return;
+	}
+
+	if (TST_ERR == EINVAL)
+		tst_brk(TCONF,
+			"kernel doesn't support PR_GET/SET_NO_NEW_PRIVS");
+
+	tst_brk(TBROK | TTERRNO,
+		"current environment doesn't permit PR_GET/SET_NO_NEW_PRIVS");
+}
+
+static const char *const resfile[] = {
+	TESTBIN,
+	NULL,
+};
+
+static struct tst_test test = {
+	.resource_files = resfile,
+	.setup = setup,
+	.test_all = verify_prctl,
+	.forks_child = 1,
+	.needs_root = 1,
+	.mount_device = 1,
+	.mntpoint = MNTPOINT,
+	.child_needs_reinit = 1,
+};
diff --git a/testcases/kernel/syscalls/prctl/prctl06_execve.c b/testcases/kernel/syscalls/prctl/prctl06_execve.c
new file mode 100644
index 000000000..92e218020
--- /dev/null
+++ b/testcases/kernel/syscalls/prctl/prctl06_execve.c
@@ -0,0 +1,52 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2019 FUJITSU LIMITED. All rights reserved.
+ * Author: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
+ *
+ * dummy program which is used by prctl06 testcase
+ */
+#define TST_NO_DEFAULT_MAIN
+#include <stdlib.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <errno.h>
+#include <pwd.h>
+#include <stdio.h>
+#include <string.h>
+#include "tst_test.h"
+
+int main(int argc, char **argv)
+{
+	char path[50];
+	struct passwd *pw;
+
+	pw = SAFE_GETPWNAM("nobody");
+
+	tst_reinit();
+	if (argc != 2)
+		tst_brk(TFAIL, "argc is %d, expected 2", argc);
+
+	strcpy(path, "/proc/self/status");
+
+	TEST(getegid());
+	if (TST_RET == 0)
+		tst_res(TFAIL,
+			"%s getegid() returns 0 unexpectedly, it gains root privileges",
+			argv[1]);
+	if (TST_RET == pw->pw_gid)
+		tst_res(TPASS,
+			"%s getegid() returns nobody, it doesn't gain root privileges",
+			argv[1]);
+
+	TEST(geteuid());
+	if (TST_RET == 0)
+		tst_res(TFAIL,
+			"%s geteuid() returns 0 unexpectedly, it gains root privileges",
+			argv[1]);
+	if (TST_RET == pw->pw_uid)
+		tst_res(TPASS,
+			"%s geteuid() returns nobody, it doesn't gain root privileges",
+			argv[1]);
+
+	return 0;
+}