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

* [LTP] [PATCH] syscalls/prctl06.c: New test for prctl() with PR_{SET, GET}_NO_NEW_PRIVS
@ 2019-05-09 12:21 Yang Xu
  2019-05-22 10:18 ` xuyang
  2019-05-23 11:52 ` Cyril Hrubis
  0 siblings, 2 replies; 15+ messages in thread
From: Yang Xu @ 2019-05-09 12:21 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    |   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




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