* [LTP] [PATCH v4] syscalls/prctl06: New test for prctl() with PR_{SET, GET}_NO_NEW_PRIVS
[not found] <20190715154945.GA28618@rei.lan>
@ 2019-07-16 5:37 ` Yang Xu
2019-07-16 9:09 ` Cyril Hrubis
0 siblings, 1 reply; 3+ messages in thread
From: Yang Xu @ 2019-07-16 5:37 UTC (permalink / raw)
To: ltp
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 | 115 ++++++++++++++++++
testcases/kernel/syscalls/prctl/prctl06.h | 64 ++++++++++
.../kernel/syscalls/prctl/prctl06_execve.c | 45 +++++++
6 files changed, 232 insertions(+)
create mode 100644 testcases/kernel/syscalls/prctl/prctl06.c
create mode 100644 testcases/kernel/syscalls/prctl/prctl06.h
create mode 100644 testcases/kernel/syscalls/prctl/prctl06_execve.c
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..eafbedfef
--- /dev/null
+++ b/testcases/kernel/syscalls/prctl/prctl06.c
@@ -0,0 +1,115 @@
+// 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),
+ * and preserved across execve(2). We also check NoNewPrivs field in
+ * /proc/self/status if it supports.
+ */
+
+#include "prctl06.h"
+
+static uid_t nobody_uid;
+static gid_t nobody_gid;
+
+static void do_prctl(void)
+{
+ char ipc_env_var[1024];
+ char *const argv[] = {BIN_PATH, "After execve, parent process", NULL};
+ char *const childargv[] = {BIN_PATH, "After 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, "After fork, child process");
+ execve(BIN_PATH, childargv, envp);
+ tst_brk(TFAIL | TTERRNO,
+ "child process failed to execute prctl_execve");
+
+ } else {
+ tst_reap_children();
+ check_no_new_privs(1, "parent process");
+ execve(BIN_PATH, 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(BIN_PATH, SUID_MODE);
+ SAFE_CHOWN(BIN_PATH, 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.h b/testcases/kernel/syscalls/prctl/prctl06.h
new file mode 100644
index 000000000..72f9c4e5a
--- /dev/null
+++ b/testcases/kernel/syscalls/prctl/prctl06.h
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2019 FUJITSU LIMITED. All rights reserved.
+ * Author: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
+ */
+#ifndef PRCTL06_H
+#define PRCTL06_H
+
+#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 PROC_STATUS "/proc/self/status"
+#define IPC_ENV_VAR "LTP_IPC_PATH"
+#define MNTPOINT "mntpoint"
+#define TESTBIN "prctl06_execve"
+#define TEST_REL_BIN_DIR MNTPOINT"/"
+#define BIN_PATH MNTPOINT"/"TESTBIN
+#define SUID_MODE (S_ISUID|S_ISGID|S_IXUSR|S_IXGRP|S_IXOTH)
+
+static int flag = 1;
+
+void check_proc_field(int val, char *name)
+{
+ int field = 0;
+
+ TEST(FILE_LINES_SCANF(PROC_STATUS, "NoNewPrivs:%d", &field));
+ if (TST_RET == 1) {
+ tst_res(TCONF,
+ "%s doesn't support NoNewPrivs field", PROC_STATUS);
+ flag = 0;
+ return;
+ }
+ if (val == field)
+ tst_res(TPASS, "%s %s NoNewPrivs field expected %d got %d",
+ name, PROC_STATUS, val, field);
+ else
+ tst_res(TFAIL, "%s %s NoNewPrivs field expected %d got %d",
+ name, PROC_STATUS, val, field);
+}
+
+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);
+}
+
+#endif
diff --git a/testcases/kernel/syscalls/prctl/prctl06_execve.c b/testcases/kernel/syscalls/prctl/prctl06_execve.c
new file mode 100644
index 000000000..d1e60e6c2
--- /dev/null
+++ b/testcases/kernel/syscalls/prctl/prctl06_execve.c
@@ -0,0 +1,45 @@
+// 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 "prctl06.h"
+
+
+int main(int argc, char **argv)
+{
+ struct passwd *pw;
+
+ pw = SAFE_GETPWNAM("nobody");
+
+ tst_reinit();
+ if (argc != 2)
+ tst_brk(TFAIL, "argc is %d, expected 2", argc);
+
+ check_no_new_privs(1, argv[1]);
+
+ 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;
+}
--
2.18.1
^ permalink raw reply related [flat|nested] 3+ messages in thread