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

Yang Xu
2019-05-09T12:21:38Z

Signed-off-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
---
include/lapi/prctl.h | 5 +
runtest/syscalls | 1 +
testcases/kernel/syscalls/prctl/.gitignore | 1 +
testcases/kernel/syscalls/prctl/Makefile | 2 +
testcases/kernel/syscalls/prctl/prctl06.c | 117 ++++++++++++++++++
.../kernel/syscalls/prctl/prctl06_execve.c | 46 +++++++
6 files changed, 172 insertions(+)
create mode 100644 testcases/kernel/syscalls/prctl/prctl06.c
create mode 100644 testcases/kernel/syscalls/prctl/prctl06_execve.c

diff --git a/include/lapi/prctl.h b/include/lapi/prctl.h
index 91da9c2d6..663ce19e9 100644
--- a/include/lapi/prctl.h
+++ b/include/lapi/prctl.h
@@ -24,4 +24,9 @@
# define PR_SET_SECCOMP 22
#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 950615bef..a43bf5e4d 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..f52f6f665 100644
--- a/testcases/kernel/syscalls/prctl/.gitignore
+++ b/testcases/kernel/syscalls/prctl/.gitignore
@@ -3,3 +3,4 @@
/prctl03
/prctl04
/prctl05
+/prctl06
diff --git a/testcases/kernel/syscalls/prctl/Makefile b/testcases/kernel/syscalls/prctl/Makefile
index bd617d806..99a9d42e7 100644
--- a/testcases/kernel/syscalls/prctl/Makefile
+++ b/testcases/kernel/syscalls/prctl/Makefile
@@ -20,4 +20,6 @@ top_srcdir ?= ../../../..

include $(top_srcdir)/include/mk/testcases.mk

+LDLIBS += $(CAP_LIBS)
+
include $(top_srcdir)/include/mk/generic_leaf_target.mk
diff --git a/testcases/kernel/syscalls/prctl/prctl06.c b/testcases/kernel/syscalls/prctl/prctl06.c
new file mode 100644
index 000000000..ba5c2bcfb
--- /dev/null
+++ b/testcases/kernel/syscalls/prctl/prctl06.c
@@ -0,0 +1,117 @@
+// 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 (as the function result) 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, execve(2) promises not to grant privileges
+ * to do anything that could not have been done without the execve(2)
+ * call(for example, rendering the set-user-ID and set-group-ID mode bits)
+ * 3)The setting of this bit is inherited by children created by fork(2) and
+ * clone(2), and preserved across execve(2).
+ */
+
+#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"
+
+static void check_no_new_privs(int val)
+{
+ TEST(prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0));
+ if (TST_RET == val)
+ tst_res(TPASS,
+ "prctl(PR_GET_NO_NEW_PRIVS) got %d "
+ "when no_new_privs was %d", val, val);
+ else
+ tst_res(TFAIL | TTERRNO,
+ "prctl(PR_GET_NO_NEW_PRIVS) expected %d got %ld",
+ val, TST_RET);
+ return;
+}
+
+static void do_prctl(void)
+{
+ char path[4096];
+ char ipc_env_var[1024];
+ char *const argv[] = {"prctl06_execve", "parent process", NULL};
+ char *const childargv[] = {"prctl06_execve", "child process", NULL};
+ char *const envp[] = {"LTP_TEST_ENV_VAR=test", ipc_env_var, NULL };
+ cap_t caps = cap_init();
+ cap_value_t capList = CAP_SETGID;
+ unsigned int num_caps = 1;
+ int childpid;
+
+ cap_set_flag(caps, CAP_EFFECTIVE, num_caps, &capList, CAP_SET);
+ cap_set_flag(caps, CAP_INHERITABLE, num_caps, &capList, CAP_SET);
+ cap_set_flag(caps, CAP_PERMITTED, num_caps, &capList, CAP_SET);
+
+ if (cap_set_proc(caps))
+ tst_brk(TFAIL | TERRNO,
+ "cap_set_flag(CAP_SETGID) failed");
+ tst_res(TINFO, "cap_set_flag(CAP_SETGID) succeeded");
+
+ check_no_new_privs(0);
+
+ 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");
+
+ check_no_new_privs(1);
+
+ if (tst_get_path("prctl06_execve", path, sizeof(path)))
+ tst_brk(TCONF, "Couldn't find prctl_execve in $PATH");
+
+ sprintf(ipc_env_var, IPC_ENV_VAR "=%s", getenv(IPC_ENV_VAR));
+ childpid = SAFE_FORK();
+ if (childpid == 0) {
+ check_no_new_privs(1);
+ execve(path, childargv, envp);
+ tst_brk(TFAIL | TERRNO,
+ "child process failed to execute prctl_execve");
+
+ } else {
+ tst_reap_children();
+ execve(path, argv, envp);
+ tst_brk(TFAIL | TERRNO,
+ "parent process failed to execute prctl_execve");
+ }
+ cap_free(caps);
+ return;
+}
+
+static void verify_prctl(void)
+{
+ int pid;
+
+ pid = SAFE_FORK();
+ if (pid == 0) {
+ do_prctl();
+ exit(0);
+ }
+ tst_reap_children();
+ return;
+}
+
+static struct tst_test test = {
+ .test_all = verify_prctl,
+ .forks_child = 1,
+ .needs_root = 1,
+ .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..84c28551c
--- /dev/null
+++ b/testcases/kernel/syscalls/prctl/prctl06_execve.c
@@ -0,0 +1,46 @@
+// 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 "tst_test.h"
+
+int main(int argc, char **argv)
+{
+ struct passwd *pw;
+ uid_t nobody_uid;
+ gid_t nobody_gid;
+
+ tst_reinit();
+ if (argc != 2)
+ tst_brk(TFAIL, "argc is %d, expected 2", argc);
+
+ pw = SAFE_GETPWNAM("nobody");
+ nobody_uid = pw->pw_uid;
+ nobody_gid = pw->pw_gid;
+ /*positive check*/
+ TEST(setgid(nobody_gid));
+ if (TST_RET == -1)
+ tst_res(TFAIL | TTERRNO,
+ "%s setgid(%d) isn't permmit", argv[1], nobody_gid);
+ else
+ tst_res(TPASS, "%s setgid(%d) succeed expectedly",
+ argv[1], nobody_gid);
+ /*negative check*/
+ TEST(setuid(nobody_uid));
+ if (TST_RET == -1)
+ tst_res(TPASS | TTERRNO,
+ "%s setuid(%d) isn't permmit", argv[1], nobody_uid);
+ else
+ tst_res(TFAIL, " %s setuid(%d) succeed unexpectedly",
+ argv[1], nobody_gid);
+ return 0;
+}
--
2.18.1