Quelle  pidfd_setns_test.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0

#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <linux/types.h>
#include <sched.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syscall.h>
#include <sys/prctl.h>
#include <sys/wait.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/stat.h>

#include "pidfd.h"
#include "../kselftest_harness.h"

enum {
 PIDFD_NS_USER,
 PIDFD_NS_MNT,
 PIDFD_NS_PID,
 PIDFD_NS_UTS,
 PIDFD_NS_IPC,
 PIDFD_NS_NET,
 PIDFD_NS_CGROUP,
 PIDFD_NS_PIDCLD,
 PIDFD_NS_TIME,
 PIDFD_NS_TIMECLD,
 PIDFD_NS_MAX
};

const struct ns_info {
 const char *name;
 int flag;
 unsigned int pidfd_ioctl;
} ns_info[] = {
 [PIDFD_NS_USER]    = { "user",              CLONE_NEWUSER,   PIDFD_GET_USER_NAMESPACE,              },
 [PIDFD_NS_MNT]     = { "mnt",               CLONE_NEWNS,     PIDFD_GET_MNT_NAMESPACE,               },
 [PIDFD_NS_PID]     = { "pid",               CLONE_NEWPID,    PIDFD_GET_PID_NAMESPACE,               },
 [PIDFD_NS_UTS]     = { "uts",               CLONE_NEWUTS,    PIDFD_GET_UTS_NAMESPACE,               },
 [PIDFD_NS_IPC]     = { "ipc",               CLONE_NEWIPC,    PIDFD_GET_IPC_NAMESPACE,               },
 [PIDFD_NS_NET]     = { "net",               CLONE_NEWNET,    PIDFD_GET_NET_NAMESPACE,               },
 [PIDFD_NS_CGROUP]  = { "cgroup",            CLONE_NEWCGROUP, PIDFD_GET_CGROUP_NAMESPACE,            },
 [PIDFD_NS_TIME]    = { "time",              CLONE_NEWTIME,   PIDFD_GET_TIME_NAMESPACE,              },
 [PIDFD_NS_PIDCLD]  = { "pid_for_children",  0,               PIDFD_GET_PID_FOR_CHILDREN_NAMESPACE,  },
 [PIDFD_NS_TIMECLD] = { "time_for_children", 0,               PIDFD_GET_TIME_FOR_CHILDREN_NAMESPACE, },
};

FIXTURE(current_nsset)
{
 pid_t pid;
 int pidfd;
 int nsfds[PIDFD_NS_MAX];
 int child_pidfd_derived_nsfds[PIDFD_NS_MAX];

 pid_t child_pid_exited;
 int child_pidfd_exited;

 pid_t child_pid1;
 int child_pidfd1;
 int child_nsfds1[PIDFD_NS_MAX];
 int child_pidfd_derived_nsfds1[PIDFD_NS_MAX];

 pid_t child_pid2;
 int child_pidfd2;
 int child_nsfds2[PIDFD_NS_MAX];
 int child_pidfd_derived_nsfds2[PIDFD_NS_MAX];
};

static bool switch_timens(void)
{
 int fd, ret;

 if (unshare(CLONE_NEWTIME))
  return false;

 fd = open("/proc/self/ns/time_for_children", O_RDONLY | O_CLOEXEC);
 if (fd < 0)
  return false;

 ret = setns(fd, CLONE_NEWTIME);
 close(fd);
 return ret == 0;
}

FIXTURE_SETUP(current_nsset)
{
 int i, proc_fd, ret;
 int ipc_sockets[2];
 char c;

 for (i = 0; i < PIDFD_NS_MAX; i++) {
  self->nsfds[i]    = -EBADF;
  self->child_nsfds1[i]   = -EBADF;
  self->child_nsfds2[i]   = -EBADF;
  self->child_pidfd_derived_nsfds[i] = -EBADF;
  self->child_pidfd_derived_nsfds1[i] = -EBADF;
  self->child_pidfd_derived_nsfds2[i] = -EBADF;
 }

 proc_fd = open("/proc/self/ns", O_DIRECTORY | O_CLOEXEC);
 ASSERT_GE(proc_fd, 0) {
  TH_LOG("%m - Failed to open /proc/self/ns");
 }

 self->pid = getpid();
 self->pidfd = sys_pidfd_open(self->pid, 0);
 EXPECT_GT(self->pidfd, 0) {
  TH_LOG("%m - Failed to open pidfd for process %d", self->pid);
 }

 for (i = 0; i < PIDFD_NS_MAX; i++) {
  const struct ns_info *info = &ns_info[i];
  self->nsfds[i] = openat(proc_fd, info->name, O_RDONLY | O_CLOEXEC);
  if (self->nsfds[i] < 0) {
   EXPECT_EQ(errno, ENOENT) {
    TH_LOG("%m - Failed to open %s namespace for process %d",
           info->name, self->pid);
   }
  }

  self->child_pidfd_derived_nsfds[i] = ioctl(self->pidfd, info->pidfd_ioctl, 0);
  if (self->child_pidfd_derived_nsfds[i] < 0) {
   EXPECT_EQ(errno, EOPNOTSUPP) {
    TH_LOG("%m - Failed to derive %s namespace from pidfd of process %d",
           info->name, self->pid);
   }
  }
 }

 /* Create task that exits right away. */
 self->child_pid_exited = create_child(&self->child_pidfd_exited, 0);
 EXPECT_GE(self->child_pid_exited, 0);

 if (self->child_pid_exited == 0) {
  if (self->nsfds[PIDFD_NS_USER] >= 0 && unshare(CLONE_NEWUSER) < 0)
   _exit(EXIT_FAILURE);
  if (self->nsfds[PIDFD_NS_NET] >= 0 && unshare(CLONE_NEWNET) < 0)
   _exit(EXIT_FAILURE);
  _exit(EXIT_SUCCESS);
 }

 ASSERT_EQ(sys_waitid(P_PID, self->child_pid_exited, NULL, WEXITED | WNOWAIT), 0);

 self->pidfd = sys_pidfd_open(self->pid, 0);
 EXPECT_GE(self->pidfd, 0) {
  TH_LOG("%m - Failed to open pidfd for process %d", self->pid);
 }

 ret = socketpair(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets);
 EXPECT_EQ(ret, 0);

 /* Create tasks that will be stopped. */
 if (self->nsfds[PIDFD_NS_USER] >= 0 && self->nsfds[PIDFD_NS_PID] >= 0)
  self->child_pid1 = create_child(&self->child_pidfd1, CLONE_NEWUSER | CLONE_NEWPID);
 else if (self->nsfds[PIDFD_NS_PID] >= 0)
  self->child_pid1 = create_child(&self->child_pidfd1, CLONE_NEWPID);
 else if (self->nsfds[PIDFD_NS_USER] >= 0)
  self->child_pid1 = create_child(&self->child_pidfd1, CLONE_NEWUSER);
 else
  self->child_pid1 = create_child(&self->child_pidfd1, 0);
 EXPECT_GE(self->child_pid1, 0);

 if (self->child_pid1 == 0) {
  close(ipc_sockets[0]);

  if (self->nsfds[PIDFD_NS_MNT] >= 0 && unshare(CLONE_NEWNS) < 0) {
   TH_LOG("%m - Failed to unshare mount namespace for process %d", self->pid);
   _exit(EXIT_FAILURE);
  }
  if (self->nsfds[PIDFD_NS_CGROUP] >= 0 && unshare(CLONE_NEWCGROUP) < 0) {
   TH_LOG("%m - Failed to unshare cgroup namespace for process %d", self->pid);
   _exit(EXIT_FAILURE);
  }
  if (self->nsfds[PIDFD_NS_IPC] >= 0 && unshare(CLONE_NEWIPC) < 0) {
   TH_LOG("%m - Failed to unshare ipc namespace for process %d", self->pid);
   _exit(EXIT_FAILURE);
  }
  if (self->nsfds[PIDFD_NS_UTS] >= 0 && unshare(CLONE_NEWUTS) < 0) {
   TH_LOG("%m - Failed to unshare uts namespace for process %d", self->pid);
   _exit(EXIT_FAILURE);
  }
  if (self->nsfds[PIDFD_NS_NET] >= 0 && unshare(CLONE_NEWNET) < 0) {
   TH_LOG("%m - Failed to unshare net namespace for process %d", self->pid);
   _exit(EXIT_FAILURE);
  }
  if (self->nsfds[PIDFD_NS_TIME] >= 0 && !switch_timens()) {
   TH_LOG("%m - Failed to unshare time namespace for process %d", self->pid);
   _exit(EXIT_FAILURE);
  }

  if (write_nointr(ipc_sockets[1], "1", 1) < 0)
   _exit(EXIT_FAILURE);

  close(ipc_sockets[1]);

  pause();
  _exit(EXIT_SUCCESS);
 }

 close(ipc_sockets[1]);
 ASSERT_EQ(read_nointr(ipc_sockets[0], &c, 1), 1);
 close(ipc_sockets[0]);

 ret = socketpair(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets);
 EXPECT_EQ(ret, 0);

 if (self->nsfds[PIDFD_NS_USER] >= 0 && self->nsfds[PIDFD_NS_PID] >= 0)
  self->child_pid2 = create_child(&self->child_pidfd2, CLONE_NEWUSER | CLONE_NEWPID);
 else if (self->nsfds[PIDFD_NS_PID] >= 0)
  self->child_pid2 = create_child(&self->child_pidfd2, CLONE_NEWPID);
 else if (self->nsfds[PIDFD_NS_USER] >= 0)
  self->child_pid2 = create_child(&self->child_pidfd2, CLONE_NEWUSER);
 else
  self->child_pid2 = create_child(&self->child_pidfd2, 0);
 EXPECT_GE(self->child_pid2, 0);

 if (self->child_pid2 == 0) {
  close(ipc_sockets[0]);

  if (self->nsfds[PIDFD_NS_MNT] >= 0 && unshare(CLONE_NEWNS) < 0) {
   TH_LOG("%m - Failed to unshare mount namespace for process %d", self->pid);
   _exit(EXIT_FAILURE);
  }
  if (self->nsfds[PIDFD_NS_CGROUP] >= 0 && unshare(CLONE_NEWCGROUP) < 0) {
   TH_LOG("%m - Failed to unshare cgroup namespace for process %d", self->pid);
   _exit(EXIT_FAILURE);
  }
  if (self->nsfds[PIDFD_NS_IPC] >= 0 && unshare(CLONE_NEWIPC) < 0) {
   TH_LOG("%m - Failed to unshare ipc namespace for process %d", self->pid);
   _exit(EXIT_FAILURE);
  }
  if (self->nsfds[PIDFD_NS_UTS] >= 0 && unshare(CLONE_NEWUTS) < 0) {
   TH_LOG("%m - Failed to unshare uts namespace for process %d", self->pid);
   _exit(EXIT_FAILURE);
  }
  if (self->nsfds[PIDFD_NS_NET] >= 0 && unshare(CLONE_NEWNET) < 0) {
   TH_LOG("%m - Failed to unshare net namespace for process %d", self->pid);
   _exit(EXIT_FAILURE);
  }
  if (self->nsfds[PIDFD_NS_TIME] >= 0 && !switch_timens()) {
   TH_LOG("%m - Failed to unshare time namespace for process %d", self->pid);
   _exit(EXIT_FAILURE);
  }

  if (write_nointr(ipc_sockets[1], "1", 1) < 0)
   _exit(EXIT_FAILURE);

  close(ipc_sockets[1]);

  pause();
  _exit(EXIT_SUCCESS);
 }

 close(ipc_sockets[1]);
 ASSERT_EQ(read_nointr(ipc_sockets[0], &c, 1), 1);
 close(ipc_sockets[0]);

 for (i = 0; i < PIDFD_NS_MAX; i++) {
  char p[100];

  const struct ns_info *info = &ns_info[i];

  self->nsfds[i] = openat(proc_fd, info->name, O_RDONLY | O_CLOEXEC);
  if (self->nsfds[i] < 0) {
   EXPECT_EQ(errno, ENOENT) {
    TH_LOG("%m - Failed to open %s namespace for process %d",
           info->name, self->pid);
   }
  }

  ret = snprintf(p, sizeof(p), "/proc/%d/ns/%s",
          self->child_pid1, info->name);
  EXPECT_GT(ret, 0);
  EXPECT_LT(ret, sizeof(p));

  self->child_nsfds1[i] = open(p, O_RDONLY | O_CLOEXEC);
  if (self->child_nsfds1[i] < 0) {
   EXPECT_EQ(errno, ENOENT) {
    TH_LOG("%m - Failed to open %s namespace for process %d",
           info->name, self->child_pid1);
   }
  }

  ret = snprintf(p, sizeof(p), "/proc/%d/ns/%s",
          self->child_pid2, info->name);
  EXPECT_GT(ret, 0);
  EXPECT_LT(ret, sizeof(p));

  self->child_nsfds2[i] = open(p, O_RDONLY | O_CLOEXEC);
  if (self->child_nsfds2[i] < 0) {
   EXPECT_EQ(errno, ENOENT) {
    TH_LOG("%m - Failed to open %s namespace for process %d",
           info->name, self->child_pid1);
   }
  }

  self->child_pidfd_derived_nsfds1[i] = ioctl(self->child_pidfd1, info->pidfd_ioctl, 0);
  if (self->child_pidfd_derived_nsfds1[i] < 0) {
   EXPECT_EQ(errno, EOPNOTSUPP) {
    TH_LOG("%m - Failed to derive %s namespace from pidfd of process %d",
           info->name, self->child_pid1);
   }
  }

  self->child_pidfd_derived_nsfds2[i] = ioctl(self->child_pidfd2, info->pidfd_ioctl, 0);
  if (self->child_pidfd_derived_nsfds2[i] < 0) {
   EXPECT_EQ(errno, EOPNOTSUPP) {
    TH_LOG("%m - Failed to derive %s namespace from pidfd of process %d",
           info->name, self->child_pid2);
   }
  }
 }

 close(proc_fd);
}

FIXTURE_TEARDOWN(current_nsset)
{
 int i;

 ASSERT_EQ(sys_pidfd_send_signal(self->child_pidfd1,
     SIGKILL, NULL, 0), 0);
 ASSERT_EQ(sys_pidfd_send_signal(self->child_pidfd2,
     SIGKILL, NULL, 0), 0);

 for (i = 0; i < PIDFD_NS_MAX; i++) {
  if (self->nsfds[i] >= 0)
   close(self->nsfds[i]);
  if (self->child_nsfds1[i] >= 0)
   close(self->child_nsfds1[i]);
  if (self->child_nsfds2[i] >= 0)
   close(self->child_nsfds2[i]);
  if (self->child_pidfd_derived_nsfds[i] >= 0)
   close(self->child_pidfd_derived_nsfds[i]);
  if (self->child_pidfd_derived_nsfds1[i] >= 0)
   close(self->child_pidfd_derived_nsfds1[i]);
  if (self->child_pidfd_derived_nsfds2[i] >= 0)
   close(self->child_pidfd_derived_nsfds2[i]);
 }

 if (self->child_pidfd1 >= 0)
  EXPECT_EQ(0, close(self->child_pidfd1));
 if (self->child_pidfd2 >= 0)
  EXPECT_EQ(0, close(self->child_pidfd2));
 ASSERT_EQ(sys_waitid(P_PID, self->child_pid_exited, NULL, WEXITED), 0);
 ASSERT_EQ(sys_waitid(P_PID, self->child_pid1, NULL, WEXITED), 0);
 ASSERT_EQ(sys_waitid(P_PID, self->child_pid2, NULL, WEXITED), 0);
}

static int preserve_ns(const int pid, const char *ns)
{
 int ret;
 char path[50];

 ret = snprintf(path, sizeof(path), "/proc/%d/ns/%s", pid, ns);
 if (ret < 0 || (size_t)ret >= sizeof(path))
  return -EIO;

 return open(path, O_RDONLY | O_CLOEXEC);
}

static int in_same_namespace(int ns_fd1, pid_t pid2, const char *ns)
{
 int ns_fd2 = -EBADF;
 int ret = -1;
 struct stat ns_st1, ns_st2;

 ret = fstat(ns_fd1, &ns_st1);
 if (ret < 0)
  return -1;

 ns_fd2 = preserve_ns(pid2, ns);
 if (ns_fd2 < 0)
  return -1;

 ret = fstat(ns_fd2, &ns_st2);
 close(ns_fd2);
 if (ret < 0)
  return -1;

 /* processes are in the same namespace */
 if ((ns_st1.st_dev == ns_st2.st_dev) &&
     (ns_st1.st_ino == ns_st2.st_ino))
  return 1;

 /* processes are in different namespaces */
 return 0;
}

/* Test that we can't pass garbage to the kernel. */
TEST_F(current_nsset, invalid_flags)
{
 ASSERT_NE(setns(self->pidfd, 0), 0);
 EXPECT_EQ(errno, EINVAL);

 ASSERT_NE(setns(self->pidfd, -1), 0);
 EXPECT_EQ(errno, EINVAL);

 ASSERT_NE(setns(self->pidfd, CLONE_VM), 0);
 EXPECT_EQ(errno, EINVAL);

 ASSERT_NE(setns(self->pidfd, CLONE_NEWUSER | CLONE_VM), 0);
 EXPECT_EQ(errno, EINVAL);
}

/* Test that we can't attach to a task that has already exited. */
TEST_F(current_nsset, pidfd_exited_child)
{
 int i;
 pid_t pid;

 ASSERT_NE(setns(self->child_pidfd_exited, CLONE_NEWUSER | CLONE_NEWNET),
    0);
 EXPECT_EQ(errno, ESRCH);

 pid = getpid();
 for (i = 0; i < PIDFD_NS_MAX; i++) {
  const struct ns_info *info = &ns_info[i];
  /* Verify that we haven't changed any namespaces. */
  if (self->nsfds[i] >= 0)
   ASSERT_EQ(in_same_namespace(self->nsfds[i], pid, info->name), 1);
 }
}

TEST_F(current_nsset, pidfd_incremental_setns)
{
 int i;
 pid_t pid;

 pid = getpid();
 for (i = 0; i < PIDFD_NS_MAX; i++) {
  const struct ns_info *info = &ns_info[i];
  int nsfd;

  if (self->child_nsfds1[i] < 0)
   continue;

  if (info->flag) {
   ASSERT_EQ(setns(self->child_pidfd1, info->flag), 0) {
    TH_LOG("%m - Failed to setns to %s namespace of %d via pidfd %d",
           info->name, self->child_pid1,
           self->child_pidfd1);
   }
  }

  /* Verify that we have changed to the correct namespaces. */
  if (info->flag == CLONE_NEWPID)
   nsfd = self->nsfds[i];
  else
   nsfd = self->child_nsfds1[i];
  ASSERT_EQ(in_same_namespace(nsfd, pid, info->name), 1) {
   TH_LOG("setns failed to place us correctly into %s namespace of %d via pidfd %d",
          info->name, self->child_pid1,
          self->child_pidfd1);
  }
  TH_LOG("Managed to correctly setns to %s namespace of %d via pidfd %d",
         info->name, self->child_pid1, self->child_pidfd1);
 }
}

TEST_F(current_nsset, nsfd_incremental_setns)
{
 int i;
 pid_t pid;

 pid = getpid();
 for (i = 0; i < PIDFD_NS_MAX; i++) {
  const struct ns_info *info = &ns_info[i];
  int nsfd;

  if (self->child_nsfds1[i] < 0)
   continue;

  if (info->flag) {
   ASSERT_EQ(setns(self->child_nsfds1[i], info->flag), 0) {
    TH_LOG("%m - Failed to setns to %s namespace of %d via nsfd %d",
           info->name, self->child_pid1,
           self->child_nsfds1[i]);
   }
  }

  /* Verify that we have changed to the correct namespaces. */
  if (info->flag == CLONE_NEWPID)
   nsfd = self->nsfds[i];
  else
   nsfd = self->child_nsfds1[i];
  ASSERT_EQ(in_same_namespace(nsfd, pid, info->name), 1) {
   TH_LOG("setns failed to place us correctly into %s namespace of %d via nsfd %d",
          info->name, self->child_pid1,
          self->child_nsfds1[i]);
  }
  TH_LOG("Managed to correctly setns to %s namespace of %d via nsfd %d",
         info->name, self->child_pid1, self->child_nsfds1[i]);
 }
}

TEST_F(current_nsset, pidfd_derived_nsfd_incremental_setns)
{
 int i;
 pid_t pid;

 pid = getpid();
 for (i = 0; i < PIDFD_NS_MAX; i++) {
  const struct ns_info *info = &ns_info[i];
  int nsfd;

  if (self->child_pidfd_derived_nsfds1[i] < 0)
   continue;

  if (info->flag) {
   ASSERT_EQ(setns(self->child_pidfd_derived_nsfds1[i], info->flag), 0) {
    TH_LOG("%m - Failed to setns to %s namespace of %d via nsfd %d",
           info->name, self->child_pid1,
           self->child_pidfd_derived_nsfds1[i]);
   }
  }

  /* Verify that we have changed to the correct namespaces. */
  if (info->flag == CLONE_NEWPID)
   nsfd = self->child_pidfd_derived_nsfds[i];
  else
   nsfd = self->child_pidfd_derived_nsfds1[i];
  ASSERT_EQ(in_same_namespace(nsfd, pid, info->name), 1) {
   TH_LOG("setns failed to place us correctly into %s namespace of %d via nsfd %d",
          info->name, self->child_pid1,
          self->child_pidfd_derived_nsfds1[i]);
  }
  TH_LOG("Managed to correctly setns to %s namespace of %d via nsfd %d",
         info->name, self->child_pid1, self->child_pidfd_derived_nsfds1[i]);
 }
}

TEST_F(current_nsset, pidfd_one_shot_setns)
{
 unsigned flags = 0;
 int i;
 pid_t pid;

 for (i = 0; i < PIDFD_NS_MAX; i++) {
  const struct ns_info *info = &ns_info[i];

  if (self->child_nsfds1[i] < 0)
   continue;

  flags |= info->flag;
  TH_LOG("Adding %s namespace of %d to list of namespaces to attach to",
         info->name, self->child_pid1);
 }

 ASSERT_EQ(setns(self->child_pidfd1, flags), 0) {
  TH_LOG("%m - Failed to setns to namespaces of %d",
         self->child_pid1);
 }

 pid = getpid();
 for (i = 0; i < PIDFD_NS_MAX; i++) {
  const struct ns_info *info = &ns_info[i];
  int nsfd;

  if (self->child_nsfds1[i] < 0)
   continue;

  /* Verify that we have changed to the correct namespaces. */
  if (info->flag == CLONE_NEWPID)
   nsfd = self->nsfds[i];
  else
   nsfd = self->child_nsfds1[i];
  ASSERT_EQ(in_same_namespace(nsfd, pid, info->name), 1) {
   TH_LOG("setns failed to place us correctly into %s namespace of %d",
          info->name, self->child_pid1);
  }
  TH_LOG("Managed to correctly setns to %s namespace of %d",
         info->name, self->child_pid1);
 }
}

TEST_F(current_nsset, no_foul_play)
{
 unsigned flags = 0;
 int i;

 for (i = 0; i < PIDFD_NS_MAX; i++) {
  const struct ns_info *info = &ns_info[i];

  if (self->child_nsfds1[i] < 0)
   continue;

  flags |= info->flag;
  if (info->flag) /* No use logging pid_for_children. */
   TH_LOG("Adding %s namespace of %d to list of namespaces to attach to",
          info->name, self->child_pid1);
 }

 ASSERT_EQ(setns(self->child_pidfd1, flags), 0) {
  TH_LOG("%m - Failed to setns to namespaces of %d vid pidfd %d",
         self->child_pid1, self->child_pidfd1);
 }

 /*
 * Can't setns to a user namespace outside of our hierarchy since we
 * don't have caps in there and didn't create it. That means that under
 * no circumstances should we be able to setns to any of the other
 * ones since they aren't owned by our user namespace.
 */
 for (i = 0; i < PIDFD_NS_MAX; i++) {
  const struct ns_info *info = &ns_info[i];

  if (self->child_nsfds2[i] < 0 || !info->flag)
   continue;

  ASSERT_NE(setns(self->child_pidfd2, info->flag), 0) {
   TH_LOG("Managed to setns to %s namespace of %d via pidfd %d",
          info->name, self->child_pid2,
          self->child_pidfd2);
  }
  TH_LOG("%m - Correctly failed to setns to %s namespace of %d via pidfd %d",
         info->name, self->child_pid2,
         self->child_pidfd2);

  ASSERT_NE(setns(self->child_nsfds2[i], info->flag), 0) {
   TH_LOG("Managed to setns to %s namespace of %d via nsfd %d",
          info->name, self->child_pid2,
          self->child_nsfds2[i]);
  }
  TH_LOG("%m - Correctly failed to setns to %s namespace of %d via nsfd %d",
         info->name, self->child_pid2,
         self->child_nsfds2[i]);
 }

 /*
 * Can't setns to a user namespace outside of our hierarchy since we
 * don't have caps in there and didn't create it. That means that under
 * no circumstances should we be able to setns to any of the other
 * ones since they aren't owned by our user namespace.
 */
 for (i = 0; i < PIDFD_NS_MAX; i++) {
  const struct ns_info *info = &ns_info[i];

  if (self->child_pidfd_derived_nsfds2[i] < 0 || !info->flag)
   continue;

  ASSERT_NE(setns(self->child_pidfd_derived_nsfds2[i], info->flag), 0) {
   TH_LOG("Managed to setns to %s namespace of %d via nsfd %d",
          info->name, self->child_pid2,
          self->child_pidfd_derived_nsfds2[i]);
  }
  TH_LOG("%m - Correctly failed to setns to %s namespace of %d via nsfd %d",
         info->name, self->child_pid2,
         self->child_pidfd_derived_nsfds2[i]);
 }
}

TEST(setns_einval)
{
 int fd;

 fd = sys_memfd_create("rostock", 0);
 EXPECT_GT(fd, 0);

 ASSERT_NE(setns(fd, 0), 0);
 EXPECT_EQ(errno, EINVAL);
 close(fd);
}

TEST_HARNESS_MAIN