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// SPDX-License-Identifier: GPL-2.0
/*
* Based on Christian Brauner's clone3() example.
* These tests are assuming to be running in the host's
* PID namespace.
*/
/* capabilities related code based on selftests/bpf/test_verifier.c */
#define _GNU_SOURCE
#include <errno.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <sys/capability.h>
#include <sys/prctl.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <sys/un.h>
#include <sys/wait.h>
#include <unistd.h>
#include <sched.h>
#include "../kselftest_harness.h"
#include "clone3_selftests.h"
#define MAX_PID_NS_LEVEL 32
static void child_exit(int ret)
{
fflush(stdout);
fflush(stderr);
_exit(ret);
}
static int call_clone3_set_tid(struct __test_metadata *_metadata,
pid_t *set_tid, size_t set_tid_size)
{
int status;
pid_t pid = -1;
struct __clone_args args = {
.exit_signal = SIGCHLD,
.set_tid = ptr_to_u64(set_tid),
.set_tid_size = set_tid_size,
};
pid = sys_clone3(&args, sizeof(args));
if (pid < 0) {
TH_LOG("%s - Failed to create new process", strerror(errno));
return -errno;
}
if (pid == 0) {
int ret;
char tmp = 0;
TH_LOG("I am the child, my PID is %d (expected %d)", getpid(), set_tid[0]);
if (set_tid[0] != getpid())
child_exit(EXIT_FAILURE);
child_exit(EXIT_SUCCESS);
}
TH_LOG("I am the parent (%d). My child's pid is %d", getpid(), pid);
if (waitpid(pid, &status, 0) < 0) {
TH_LOG("Child returned %s", strerror(errno));
return -errno;
}
if (!WIFEXITED(status))
return -1;
return WEXITSTATUS(status);
}
static int test_clone3_set_tid(struct __test_metadata *_metadata,
pid_t *set_tid, size_t set_tid_size)
{
int ret;
TH_LOG("[%d] Trying clone3() with CLONE_SET_TID to %d", getpid(), set_tid[0]);
ret = call_clone3_set_tid(_metadata, set_tid, set_tid_size);
TH_LOG("[%d] clone3() with CLONE_SET_TID %d says:%d", getpid(), set_tid[0], ret);
return ret;
}
struct libcap {
struct __user_cap_header_struct hdr;
struct __user_cap_data_struct data[2];
};
static int set_capability(void)
{
cap_value_t cap_values[] = { CAP_SETUID, CAP_SETGID };
struct libcap *cap;
int ret = -1;
cap_t caps;
caps = cap_get_proc();
if (!caps) {
perror("cap_get_proc");
return -1;
}
/* Drop all capabilities */
if (cap_clear(caps)) {
perror("cap_clear");
goto out;
}
cap_set_flag(caps, CAP_EFFECTIVE, 2, cap_values, CAP_SET);
cap_set_flag(caps, CAP_PERMITTED, 2, cap_values, CAP_SET);
cap = (struct libcap *) caps;
/* 40 -> CAP_CHECKPOINT_RESTORE */
cap->data[1].effective |= 1 << (40 - 32);
cap->data[1].permitted |= 1 << (40 - 32);
if (cap_set_proc(caps)) {
perror("cap_set_proc");
goto out;
}
ret = 0;
out:
if (cap_free(caps))
perror("cap_free");
return ret;
}
TEST(clone3_cap_checkpoint_restore)
{
pid_t pid;
int status;
int ret = 0;
pid_t set_tid[1];
test_clone3_supported();
EXPECT_EQ(getuid(), 0)
SKIP(return, "Skipping all tests as non-root");
memset(&set_tid, 0, sizeof(set_tid));
/* Find the current active PID */
pid = fork();
if (pid == 0) {
TH_LOG("Child has PID %d", getpid());
child_exit(EXIT_SUCCESS);
}
ASSERT_GT(waitpid(pid, &status, 0), 0)
TH_LOG("Waiting for child %d failed", pid);
/* After the child has finished, its PID should be free. */
set_tid[0] = pid;
ASSERT_EQ(set_capability(), 0)
TH_LOG("Could not set CAP_CHECKPOINT_RESTORE");
ASSERT_EQ(prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0), 0);
EXPECT_EQ(setgid(65534), 0)
TH_LOG("Failed to setgid(65534)");
ASSERT_EQ(setuid(65534), 0);
set_tid[0] = pid;
/* This would fail without CAP_CHECKPOINT_RESTORE */
ASSERT_EQ(test_clone3_set_tid(_metadata, set_tid, 1), -EPERM);
ASSERT_EQ(set_capability(), 0)
TH_LOG("Could not set CAP_CHECKPOINT_RESTORE");
/* This should work as we have CAP_CHECKPOINT_RESTORE as non-root */
ASSERT_EQ(test_clone3_set_tid(_metadata, set_tid, 1), 0);
}
TEST_HARNESS_MAIN
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