Add a bunch of selftests for namespace file handles.
Reviewed-by: Amir Goldstein amir73il@gmail.com Signed-off-by: Christian Brauner brauner@kernel.org --- tools/testing/selftests/namespaces/.gitignore | 1 + tools/testing/selftests/namespaces/Makefile | 2 +- .../selftests/namespaces/file_handle_test.c | 1429 ++++++++++++++++++++ 3 files changed, 1431 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/namespaces/.gitignore b/tools/testing/selftests/namespaces/.gitignore index c1e8d634dd21..7639dbf58bbf 100644 --- a/tools/testing/selftests/namespaces/.gitignore +++ b/tools/testing/selftests/namespaces/.gitignore @@ -1 +1,2 @@ nsid_test +file_handle_test diff --git a/tools/testing/selftests/namespaces/Makefile b/tools/testing/selftests/namespaces/Makefile index 9280c703533e..f6c117ce2c2b 100644 --- a/tools/testing/selftests/namespaces/Makefile +++ b/tools/testing/selftests/namespaces/Makefile @@ -1,7 +1,7 @@ # SPDX-License-Identifier: GPL-2.0-only CFLAGS += -Wall -O0 -g $(KHDR_INCLUDES) $(TOOLS_INCLUDES)
-TEST_GEN_PROGS := nsid_test +TEST_GEN_PROGS := nsid_test file_handle_test
include ../lib.mk
diff --git a/tools/testing/selftests/namespaces/file_handle_test.c b/tools/testing/selftests/namespaces/file_handle_test.c new file mode 100644 index 000000000000..f1bc5773f552 --- /dev/null +++ b/tools/testing/selftests/namespaces/file_handle_test.c @@ -0,0 +1,1429 @@ +// SPDX-License-Identifier: GPL-2.0 +#define _GNU_SOURCE +#include <errno.h> +#include <fcntl.h> +#include <grp.h> +#include <limits.h> +#include <sched.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/mount.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <unistd.h> +#include <linux/unistd.h> +#include "../kselftest_harness.h" + +#ifndef FD_NSFS_ROOT +#define FD_NSFS_ROOT -10003 /* Root of the nsfs filesystem */ +#endif + +TEST(nsfs_net_handle) +{ + struct file_handle *handle; + int mount_id; + int ret; + int fd; + int ns_fd; + struct stat st1, st2; + + /* Drop to unprivileged uid/gid */ + ASSERT_EQ(setresgid(65534, 65534, 65534), 0); /* nogroup */ + ASSERT_EQ(setresuid(65534, 65534, 65534), 0); /* nobody */ + + handle = malloc(sizeof(*handle) + MAX_HANDLE_SZ); + ASSERT_NE(handle, NULL); + + /* Open a namespace file descriptor */ + ns_fd = open("/proc/self/ns/net", O_RDONLY); + ASSERT_GE(ns_fd, 0); + + /* Get handle for the namespace */ + handle->handle_bytes = MAX_HANDLE_SZ; + ret = name_to_handle_at(ns_fd, "", handle, &mount_id, AT_EMPTY_PATH); + if (ret < 0 && errno == EOPNOTSUPP) { + SKIP(free(handle); close(ns_fd); + return, "nsfs doesn't support file handles"); + } + ASSERT_EQ(ret, 0); + ASSERT_GT(handle->handle_bytes, 0); + + /* Try to open using FD_NSFS_ROOT as unprivileged user */ + fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_RDONLY); + if (fd < 0 && (errno == EINVAL || errno == EOPNOTSUPP)) { + SKIP(free(handle); close(ns_fd); + return, + "open_by_handle_at with FD_NSFS_ROOT not supported"); + } + if (fd < 0 && errno == EPERM) { + SKIP(free(handle); close(ns_fd); + return, + "Permission denied for unprivileged user (expected)"); + } + ASSERT_GE(fd, 0); + + /* Verify we opened the correct namespace */ + ASSERT_EQ(fstat(ns_fd, &st1), 0); + ASSERT_EQ(fstat(fd, &st2), 0); + ASSERT_EQ(st1.st_ino, st2.st_ino); + ASSERT_EQ(st1.st_dev, st2.st_dev); + + close(fd); + close(ns_fd); + free(handle); +} + +TEST(nsfs_uts_handle) +{ + struct file_handle *handle; + int mount_id; + int ret; + int fd; + int ns_fd; + struct stat st1, st2; + + /* Drop to unprivileged uid/gid */ + ASSERT_EQ(setresgid(65534, 65534, 65534), 0); /* nogroup */ + ASSERT_EQ(setresuid(65534, 65534, 65534), 0); /* nobody */ + + handle = malloc(sizeof(*handle) + MAX_HANDLE_SZ); + ASSERT_NE(handle, NULL); + + /* Open UTS namespace file descriptor */ + ns_fd = open("/proc/self/ns/uts", O_RDONLY); + ASSERT_GE(ns_fd, 0); + + /* Get handle for the namespace */ + handle->handle_bytes = MAX_HANDLE_SZ; + ret = name_to_handle_at(ns_fd, "", handle, &mount_id, AT_EMPTY_PATH); + if (ret < 0 && errno == EOPNOTSUPP) { + SKIP(free(handle); close(ns_fd); + return, "nsfs doesn't support file handles"); + } + ASSERT_EQ(ret, 0); + ASSERT_GT(handle->handle_bytes, 0); + + /* Try to open using FD_NSFS_ROOT */ + fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_RDONLY); + if (fd < 0 && (errno == EINVAL || errno == EOPNOTSUPP)) { + SKIP(free(handle); close(ns_fd); + return, + "open_by_handle_at with FD_NSFS_ROOT not supported"); + } + ASSERT_GE(fd, 0); + + /* Verify we opened the correct namespace */ + ASSERT_EQ(fstat(ns_fd, &st1), 0); + ASSERT_EQ(fstat(fd, &st2), 0); + ASSERT_EQ(st1.st_ino, st2.st_ino); + ASSERT_EQ(st1.st_dev, st2.st_dev); + + close(fd); + close(ns_fd); + free(handle); +} + +TEST(nsfs_ipc_handle) +{ + struct file_handle *handle; + int mount_id; + int ret; + int fd; + int ns_fd; + struct stat st1, st2; + + /* Drop to unprivileged uid/gid */ + ASSERT_EQ(setresgid(65534, 65534, 65534), 0); /* nogroup */ + ASSERT_EQ(setresuid(65534, 65534, 65534), 0); /* nobody */ + + handle = malloc(sizeof(*handle) + MAX_HANDLE_SZ); + ASSERT_NE(handle, NULL); + + /* Open IPC namespace file descriptor */ + ns_fd = open("/proc/self/ns/ipc", O_RDONLY); + ASSERT_GE(ns_fd, 0); + + /* Get handle for the namespace */ + handle->handle_bytes = MAX_HANDLE_SZ; + ret = name_to_handle_at(ns_fd, "", handle, &mount_id, AT_EMPTY_PATH); + if (ret < 0 && errno == EOPNOTSUPP) { + SKIP(free(handle); close(ns_fd); + return, "nsfs doesn't support file handles"); + } + ASSERT_EQ(ret, 0); + ASSERT_GT(handle->handle_bytes, 0); + + /* Try to open using FD_NSFS_ROOT */ + fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_RDONLY); + if (fd < 0 && (errno == EINVAL || errno == EOPNOTSUPP)) { + SKIP(free(handle); close(ns_fd); + return, + "open_by_handle_at with FD_NSFS_ROOT not supported"); + } + ASSERT_GE(fd, 0); + + /* Verify we opened the correct namespace */ + ASSERT_EQ(fstat(ns_fd, &st1), 0); + ASSERT_EQ(fstat(fd, &st2), 0); + ASSERT_EQ(st1.st_ino, st2.st_ino); + ASSERT_EQ(st1.st_dev, st2.st_dev); + + close(fd); + close(ns_fd); + free(handle); +} + +TEST(nsfs_pid_handle) +{ + struct file_handle *handle; + int mount_id; + int ret; + int fd; + int ns_fd; + struct stat st1, st2; + + /* Drop to unprivileged uid/gid */ + ASSERT_EQ(setresgid(65534, 65534, 65534), 0); /* nogroup */ + ASSERT_EQ(setresuid(65534, 65534, 65534), 0); /* nobody */ + + handle = malloc(sizeof(*handle) + MAX_HANDLE_SZ); + ASSERT_NE(handle, NULL); + + /* Open PID namespace file descriptor */ + ns_fd = open("/proc/self/ns/pid", O_RDONLY); + ASSERT_GE(ns_fd, 0); + + /* Get handle for the namespace */ + handle->handle_bytes = MAX_HANDLE_SZ; + ret = name_to_handle_at(ns_fd, "", handle, &mount_id, AT_EMPTY_PATH); + if (ret < 0 && errno == EOPNOTSUPP) { + SKIP(free(handle); close(ns_fd); + return, "nsfs doesn't support file handles"); + } + ASSERT_EQ(ret, 0); + ASSERT_GT(handle->handle_bytes, 0); + + /* Try to open using FD_NSFS_ROOT */ + fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_RDONLY); + if (fd < 0 && (errno == EINVAL || errno == EOPNOTSUPP)) { + SKIP(free(handle); close(ns_fd); + return, + "open_by_handle_at with FD_NSFS_ROOT not supported"); + } + ASSERT_GE(fd, 0); + + /* Verify we opened the correct namespace */ + ASSERT_EQ(fstat(ns_fd, &st1), 0); + ASSERT_EQ(fstat(fd, &st2), 0); + ASSERT_EQ(st1.st_ino, st2.st_ino); + ASSERT_EQ(st1.st_dev, st2.st_dev); + + close(fd); + close(ns_fd); + free(handle); +} + +TEST(nsfs_mnt_handle) +{ + struct file_handle *handle; + int mount_id; + int ret; + int fd; + int ns_fd; + struct stat st1, st2; + + /* Drop to unprivileged uid/gid */ + ASSERT_EQ(setresgid(65534, 65534, 65534), 0); /* nogroup */ + ASSERT_EQ(setresuid(65534, 65534, 65534), 0); /* nobody */ + + handle = malloc(sizeof(*handle) + MAX_HANDLE_SZ); + ASSERT_NE(handle, NULL); + + /* Open mount namespace file descriptor */ + ns_fd = open("/proc/self/ns/mnt", O_RDONLY); + ASSERT_GE(ns_fd, 0); + + /* Get handle for the namespace */ + handle->handle_bytes = MAX_HANDLE_SZ; + ret = name_to_handle_at(ns_fd, "", handle, &mount_id, AT_EMPTY_PATH); + if (ret < 0 && errno == EOPNOTSUPP) { + SKIP(free(handle); close(ns_fd); + return, "nsfs doesn't support file handles"); + } + ASSERT_EQ(ret, 0); + ASSERT_GT(handle->handle_bytes, 0); + + /* Try to open using FD_NSFS_ROOT */ + fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_RDONLY); + if (fd < 0 && (errno == EINVAL || errno == EOPNOTSUPP)) { + SKIP(free(handle); close(ns_fd); + return, + "open_by_handle_at with FD_NSFS_ROOT not supported"); + } + ASSERT_GE(fd, 0); + + /* Verify we opened the correct namespace */ + ASSERT_EQ(fstat(ns_fd, &st1), 0); + ASSERT_EQ(fstat(fd, &st2), 0); + ASSERT_EQ(st1.st_ino, st2.st_ino); + ASSERT_EQ(st1.st_dev, st2.st_dev); + + close(fd); + close(ns_fd); + free(handle); +} + +TEST(nsfs_user_handle) +{ + struct file_handle *handle; + int mount_id; + int ret; + int fd; + int ns_fd; + struct stat st1, st2; + + /* Drop to unprivileged uid/gid */ + ASSERT_EQ(setresgid(65534, 65534, 65534), 0); /* nogroup */ + ASSERT_EQ(setresuid(65534, 65534, 65534), 0); /* nobody */ + + handle = malloc(sizeof(*handle) + MAX_HANDLE_SZ); + ASSERT_NE(handle, NULL); + + /* Open user namespace file descriptor */ + ns_fd = open("/proc/self/ns/user", O_RDONLY); + ASSERT_GE(ns_fd, 0); + + /* Get handle for the namespace */ + handle->handle_bytes = MAX_HANDLE_SZ; + ret = name_to_handle_at(ns_fd, "", handle, &mount_id, AT_EMPTY_PATH); + if (ret < 0 && errno == EOPNOTSUPP) { + SKIP(free(handle); close(ns_fd); + return, "nsfs doesn't support file handles"); + } + ASSERT_EQ(ret, 0); + ASSERT_GT(handle->handle_bytes, 0); + + /* Try to open using FD_NSFS_ROOT */ + fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_RDONLY); + if (fd < 0 && (errno == EINVAL || errno == EOPNOTSUPP)) { + SKIP(free(handle); close(ns_fd); + return, + "open_by_handle_at with FD_NSFS_ROOT not supported"); + } + ASSERT_GE(fd, 0); + + /* Verify we opened the correct namespace */ + ASSERT_EQ(fstat(ns_fd, &st1), 0); + ASSERT_EQ(fstat(fd, &st2), 0); + ASSERT_EQ(st1.st_ino, st2.st_ino); + ASSERT_EQ(st1.st_dev, st2.st_dev); + + close(fd); + close(ns_fd); + free(handle); +} + +TEST(nsfs_cgroup_handle) +{ + struct file_handle *handle; + int mount_id; + int ret; + int fd; + int ns_fd; + struct stat st1, st2; + + /* Drop to unprivileged uid/gid */ + ASSERT_EQ(setresgid(65534, 65534, 65534), 0); /* nogroup */ + ASSERT_EQ(setresuid(65534, 65534, 65534), 0); /* nobody */ + + handle = malloc(sizeof(*handle) + MAX_HANDLE_SZ); + ASSERT_NE(handle, NULL); + + /* Open cgroup namespace file descriptor */ + ns_fd = open("/proc/self/ns/cgroup", O_RDONLY); + if (ns_fd < 0) { + SKIP(free(handle); return, "cgroup namespace not available"); + } + + /* Get handle for the namespace */ + handle->handle_bytes = MAX_HANDLE_SZ; + ret = name_to_handle_at(ns_fd, "", handle, &mount_id, AT_EMPTY_PATH); + if (ret < 0 && errno == EOPNOTSUPP) { + SKIP(free(handle); close(ns_fd); + return, "nsfs doesn't support file handles"); + } + ASSERT_EQ(ret, 0); + ASSERT_GT(handle->handle_bytes, 0); + + /* Try to open using FD_NSFS_ROOT */ + fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_RDONLY); + if (fd < 0 && (errno == EINVAL || errno == EOPNOTSUPP)) { + SKIP(free(handle); close(ns_fd); + return, + "open_by_handle_at with FD_NSFS_ROOT not supported"); + } + ASSERT_GE(fd, 0); + + /* Verify we opened the correct namespace */ + ASSERT_EQ(fstat(ns_fd, &st1), 0); + ASSERT_EQ(fstat(fd, &st2), 0); + ASSERT_EQ(st1.st_ino, st2.st_ino); + ASSERT_EQ(st1.st_dev, st2.st_dev); + + close(fd); + close(ns_fd); + free(handle); +} + +TEST(nsfs_time_handle) +{ + struct file_handle *handle; + int mount_id; + int ret; + int fd; + int ns_fd; + struct stat st1, st2; + + /* Drop to unprivileged uid/gid */ + ASSERT_EQ(setresgid(65534, 65534, 65534), 0); /* nogroup */ + ASSERT_EQ(setresuid(65534, 65534, 65534), 0); /* nobody */ + + handle = malloc(sizeof(*handle) + MAX_HANDLE_SZ); + ASSERT_NE(handle, NULL); + + /* Open time namespace file descriptor */ + ns_fd = open("/proc/self/ns/time", O_RDONLY); + if (ns_fd < 0) { + SKIP(free(handle); return, "time namespace not available"); + } + + /* Get handle for the namespace */ + handle->handle_bytes = MAX_HANDLE_SZ; + ret = name_to_handle_at(ns_fd, "", handle, &mount_id, AT_EMPTY_PATH); + if (ret < 0 && errno == EOPNOTSUPP) { + SKIP(free(handle); close(ns_fd); + return, "nsfs doesn't support file handles"); + } + ASSERT_EQ(ret, 0); + ASSERT_GT(handle->handle_bytes, 0); + + /* Try to open using FD_NSFS_ROOT */ + fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_RDONLY); + if (fd < 0 && (errno == EINVAL || errno == EOPNOTSUPP)) { + SKIP(free(handle); close(ns_fd); + return, + "open_by_handle_at with FD_NSFS_ROOT not supported"); + } + ASSERT_GE(fd, 0); + + /* Verify we opened the correct namespace */ + ASSERT_EQ(fstat(ns_fd, &st1), 0); + ASSERT_EQ(fstat(fd, &st2), 0); + ASSERT_EQ(st1.st_ino, st2.st_ino); + ASSERT_EQ(st1.st_dev, st2.st_dev); + + close(fd); + close(ns_fd); + free(handle); +} + +TEST(nsfs_user_net_namespace_isolation) +{ + struct file_handle *handle; + int mount_id; + int ret; + int fd; + int ns_fd; + pid_t pid; + int status; + int pipefd[2]; + char result; + + handle = malloc(sizeof(*handle) + MAX_HANDLE_SZ); + ASSERT_NE(handle, NULL); + + /* Create pipe for communication */ + ASSERT_EQ(pipe(pipefd), 0); + + /* Get handle for current network namespace */ + ns_fd = open("/proc/self/ns/net", O_RDONLY); + ASSERT_GE(ns_fd, 0); + + handle->handle_bytes = MAX_HANDLE_SZ; + ret = name_to_handle_at(ns_fd, "", handle, &mount_id, AT_EMPTY_PATH); + if (ret < 0 && errno == EOPNOTSUPP) { + SKIP(free(handle); close(ns_fd); close(pipefd[0]); + close(pipefd[1]); + return, "nsfs doesn't support file handles"); + } + ASSERT_EQ(ret, 0); + close(ns_fd); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) { + /* Child process */ + close(pipefd[0]); + + /* First create new user namespace to drop privileges */ + ret = unshare(CLONE_NEWUSER); + if (ret < 0) { + write(pipefd[1], "U", + 1); /* Unable to create user namespace */ + close(pipefd[1]); + exit(0); + } + + /* Write uid/gid mappings to maintain some capabilities */ + int uid_map_fd = open("/proc/self/uid_map", O_WRONLY); + int gid_map_fd = open("/proc/self/gid_map", O_WRONLY); + int setgroups_fd = open("/proc/self/setgroups", O_WRONLY); + + if (uid_map_fd < 0 || gid_map_fd < 0 || setgroups_fd < 0) { + write(pipefd[1], "M", 1); /* Unable to set mappings */ + close(pipefd[1]); + exit(0); + } + + /* Disable setgroups to allow gid mapping */ + write(setgroups_fd, "deny", 4); + close(setgroups_fd); + + /* Map current uid/gid to root in the new namespace */ + char mapping[64]; + snprintf(mapping, sizeof(mapping), "0 %d 1", getuid()); + write(uid_map_fd, mapping, strlen(mapping)); + close(uid_map_fd); + + snprintf(mapping, sizeof(mapping), "0 %d 1", getgid()); + write(gid_map_fd, mapping, strlen(mapping)); + close(gid_map_fd); + + /* Now create new network namespace */ + ret = unshare(CLONE_NEWNET); + if (ret < 0) { + write(pipefd[1], "N", + 1); /* Unable to create network namespace */ + close(pipefd[1]); + exit(0); + } + + /* Try to open parent's network namespace handle from new user+net namespace */ + fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_RDONLY); + + if (fd >= 0) { + /* Should NOT succeed - we're in a different user namespace */ + write(pipefd[1], "S", 1); /* Unexpected success */ + close(fd); + } else if (errno == ESTALE) { + /* Expected: Stale file handle */ + write(pipefd[1], "P", 1); + } else { + /* Other error */ + write(pipefd[1], "F", 1); + } + + close(pipefd[1]); + exit(0); + } + + /* Parent process */ + close(pipefd[1]); + ASSERT_EQ(read(pipefd[0], &result, 1), 1); + + waitpid(pid, &status, 0); + ASSERT_TRUE(WIFEXITED(status)); + ASSERT_EQ(WEXITSTATUS(status), 0); + + if (result == 'U') { + SKIP(free(handle); close(pipefd[0]); + return, "Cannot create new user namespace"); + } + if (result == 'M') { + SKIP(free(handle); close(pipefd[0]); + return, "Cannot set uid/gid mappings"); + } + if (result == 'N') { + SKIP(free(handle); close(pipefd[0]); + return, "Cannot create new network namespace"); + } + + /* Should fail with permission denied since we're in a different user namespace */ + ASSERT_EQ(result, 'P'); + + close(pipefd[0]); + free(handle); +} + +TEST(nsfs_user_uts_namespace_isolation) +{ + struct file_handle *handle; + int mount_id; + int ret; + int fd; + int ns_fd; + pid_t pid; + int status; + int pipefd[2]; + char result; + + handle = malloc(sizeof(*handle) + MAX_HANDLE_SZ); + ASSERT_NE(handle, NULL); + + /* Create pipe for communication */ + ASSERT_EQ(pipe(pipefd), 0); + + /* Get handle for current UTS namespace */ + ns_fd = open("/proc/self/ns/uts", O_RDONLY); + ASSERT_GE(ns_fd, 0); + + handle->handle_bytes = MAX_HANDLE_SZ; + ret = name_to_handle_at(ns_fd, "", handle, &mount_id, AT_EMPTY_PATH); + if (ret < 0 && errno == EOPNOTSUPP) { + SKIP(free(handle); close(ns_fd); close(pipefd[0]); + close(pipefd[1]); + return, "nsfs doesn't support file handles"); + } + ASSERT_EQ(ret, 0); + close(ns_fd); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) { + /* Child process */ + close(pipefd[0]); + + /* First create new user namespace to drop privileges */ + ret = unshare(CLONE_NEWUSER); + if (ret < 0) { + write(pipefd[1], "U", + 1); /* Unable to create user namespace */ + close(pipefd[1]); + exit(0); + } + + /* Write uid/gid mappings to maintain some capabilities */ + int uid_map_fd = open("/proc/self/uid_map", O_WRONLY); + int gid_map_fd = open("/proc/self/gid_map", O_WRONLY); + int setgroups_fd = open("/proc/self/setgroups", O_WRONLY); + + if (uid_map_fd < 0 || gid_map_fd < 0 || setgroups_fd < 0) { + write(pipefd[1], "M", 1); /* Unable to set mappings */ + close(pipefd[1]); + exit(0); + } + + /* Disable setgroups to allow gid mapping */ + write(setgroups_fd, "deny", 4); + close(setgroups_fd); + + /* Map current uid/gid to root in the new namespace */ + char mapping[64]; + snprintf(mapping, sizeof(mapping), "0 %d 1", getuid()); + write(uid_map_fd, mapping, strlen(mapping)); + close(uid_map_fd); + + snprintf(mapping, sizeof(mapping), "0 %d 1", getgid()); + write(gid_map_fd, mapping, strlen(mapping)); + close(gid_map_fd); + + /* Now create new UTS namespace */ + ret = unshare(CLONE_NEWUTS); + if (ret < 0) { + write(pipefd[1], "N", + 1); /* Unable to create UTS namespace */ + close(pipefd[1]); + exit(0); + } + + /* Try to open parent's UTS namespace handle from new user+uts namespace */ + fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_RDONLY); + + if (fd >= 0) { + /* Should NOT succeed - we're in a different user namespace */ + write(pipefd[1], "S", 1); /* Unexpected success */ + close(fd); + } else if (errno == ESTALE) { + /* Expected: Stale file handle */ + write(pipefd[1], "P", 1); + } else { + /* Other error */ + write(pipefd[1], "F", 1); + } + + close(pipefd[1]); + exit(0); + } + + /* Parent process */ + close(pipefd[1]); + ASSERT_EQ(read(pipefd[0], &result, 1), 1); + + waitpid(pid, &status, 0); + ASSERT_TRUE(WIFEXITED(status)); + ASSERT_EQ(WEXITSTATUS(status), 0); + + if (result == 'U') { + SKIP(free(handle); close(pipefd[0]); + return, "Cannot create new user namespace"); + } + if (result == 'M') { + SKIP(free(handle); close(pipefd[0]); + return, "Cannot set uid/gid mappings"); + } + if (result == 'N') { + SKIP(free(handle); close(pipefd[0]); + return, "Cannot create new UTS namespace"); + } + + /* Should fail with ESTALE since we're in a different user namespace */ + ASSERT_EQ(result, 'P'); + + close(pipefd[0]); + free(handle); +} + +TEST(nsfs_user_ipc_namespace_isolation) +{ + struct file_handle *handle; + int mount_id; + int ret; + int fd; + int ns_fd; + pid_t pid; + int status; + int pipefd[2]; + char result; + + handle = malloc(sizeof(*handle) + MAX_HANDLE_SZ); + ASSERT_NE(handle, NULL); + + /* Create pipe for communication */ + ASSERT_EQ(pipe(pipefd), 0); + + /* Get handle for current IPC namespace */ + ns_fd = open("/proc/self/ns/ipc", O_RDONLY); + ASSERT_GE(ns_fd, 0); + + handle->handle_bytes = MAX_HANDLE_SZ; + ret = name_to_handle_at(ns_fd, "", handle, &mount_id, AT_EMPTY_PATH); + if (ret < 0 && errno == EOPNOTSUPP) { + SKIP(free(handle); close(ns_fd); close(pipefd[0]); + close(pipefd[1]); + return, "nsfs doesn't support file handles"); + } + ASSERT_EQ(ret, 0); + close(ns_fd); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) { + /* Child process */ + close(pipefd[0]); + + /* First create new user namespace to drop privileges */ + ret = unshare(CLONE_NEWUSER); + if (ret < 0) { + write(pipefd[1], "U", + 1); /* Unable to create user namespace */ + close(pipefd[1]); + exit(0); + } + + /* Write uid/gid mappings to maintain some capabilities */ + int uid_map_fd = open("/proc/self/uid_map", O_WRONLY); + int gid_map_fd = open("/proc/self/gid_map", O_WRONLY); + int setgroups_fd = open("/proc/self/setgroups", O_WRONLY); + + if (uid_map_fd < 0 || gid_map_fd < 0 || setgroups_fd < 0) { + write(pipefd[1], "M", 1); /* Unable to set mappings */ + close(pipefd[1]); + exit(0); + } + + /* Disable setgroups to allow gid mapping */ + write(setgroups_fd, "deny", 4); + close(setgroups_fd); + + /* Map current uid/gid to root in the new namespace */ + char mapping[64]; + snprintf(mapping, sizeof(mapping), "0 %d 1", getuid()); + write(uid_map_fd, mapping, strlen(mapping)); + close(uid_map_fd); + + snprintf(mapping, sizeof(mapping), "0 %d 1", getgid()); + write(gid_map_fd, mapping, strlen(mapping)); + close(gid_map_fd); + + /* Now create new IPC namespace */ + ret = unshare(CLONE_NEWIPC); + if (ret < 0) { + write(pipefd[1], "N", + 1); /* Unable to create IPC namespace */ + close(pipefd[1]); + exit(0); + } + + /* Try to open parent's IPC namespace handle from new user+ipc namespace */ + fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_RDONLY); + + if (fd >= 0) { + /* Should NOT succeed - we're in a different user namespace */ + write(pipefd[1], "S", 1); /* Unexpected success */ + close(fd); + } else if (errno == ESTALE) { + /* Expected: Stale file handle */ + write(pipefd[1], "P", 1); + } else { + /* Other error */ + write(pipefd[1], "F", 1); + } + + close(pipefd[1]); + exit(0); + } + + /* Parent process */ + close(pipefd[1]); + ASSERT_EQ(read(pipefd[0], &result, 1), 1); + + waitpid(pid, &status, 0); + ASSERT_TRUE(WIFEXITED(status)); + ASSERT_EQ(WEXITSTATUS(status), 0); + + if (result == 'U') { + SKIP(free(handle); close(pipefd[0]); + return, "Cannot create new user namespace"); + } + if (result == 'M') { + SKIP(free(handle); close(pipefd[0]); + return, "Cannot set uid/gid mappings"); + } + if (result == 'N') { + SKIP(free(handle); close(pipefd[0]); + return, "Cannot create new IPC namespace"); + } + + /* Should fail with ESTALE since we're in a different user namespace */ + ASSERT_EQ(result, 'P'); + + close(pipefd[0]); + free(handle); +} + +TEST(nsfs_user_mnt_namespace_isolation) +{ + struct file_handle *handle; + int mount_id; + int ret; + int fd; + int ns_fd; + pid_t pid; + int status; + int pipefd[2]; + char result; + + handle = malloc(sizeof(*handle) + MAX_HANDLE_SZ); + ASSERT_NE(handle, NULL); + + /* Create pipe for communication */ + ASSERT_EQ(pipe(pipefd), 0); + + /* Get handle for current mount namespace */ + ns_fd = open("/proc/self/ns/mnt", O_RDONLY); + ASSERT_GE(ns_fd, 0); + + handle->handle_bytes = MAX_HANDLE_SZ; + ret = name_to_handle_at(ns_fd, "", handle, &mount_id, AT_EMPTY_PATH); + if (ret < 0 && errno == EOPNOTSUPP) { + SKIP(free(handle); close(ns_fd); close(pipefd[0]); + close(pipefd[1]); + return, "nsfs doesn't support file handles"); + } + ASSERT_EQ(ret, 0); + close(ns_fd); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) { + /* Child process */ + close(pipefd[0]); + + /* First create new user namespace to drop privileges */ + ret = unshare(CLONE_NEWUSER); + if (ret < 0) { + write(pipefd[1], "U", + 1); /* Unable to create user namespace */ + close(pipefd[1]); + exit(0); + } + + /* Write uid/gid mappings to maintain some capabilities */ + int uid_map_fd = open("/proc/self/uid_map", O_WRONLY); + int gid_map_fd = open("/proc/self/gid_map", O_WRONLY); + int setgroups_fd = open("/proc/self/setgroups", O_WRONLY); + + if (uid_map_fd < 0 || gid_map_fd < 0 || setgroups_fd < 0) { + write(pipefd[1], "M", 1); /* Unable to set mappings */ + close(pipefd[1]); + exit(0); + } + + /* Disable setgroups to allow gid mapping */ + write(setgroups_fd, "deny", 4); + close(setgroups_fd); + + /* Map current uid/gid to root in the new namespace */ + char mapping[64]; + snprintf(mapping, sizeof(mapping), "0 %d 1", getuid()); + write(uid_map_fd, mapping, strlen(mapping)); + close(uid_map_fd); + + snprintf(mapping, sizeof(mapping), "0 %d 1", getgid()); + write(gid_map_fd, mapping, strlen(mapping)); + close(gid_map_fd); + + /* Now create new mount namespace */ + ret = unshare(CLONE_NEWNS); + if (ret < 0) { + write(pipefd[1], "N", + 1); /* Unable to create mount namespace */ + close(pipefd[1]); + exit(0); + } + + /* Try to open parent's mount namespace handle from new user+mnt namespace */ + fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_RDONLY); + + if (fd >= 0) { + /* Should NOT succeed - we're in a different user namespace */ + write(pipefd[1], "S", 1); /* Unexpected success */ + close(fd); + } else if (errno == ESTALE) { + /* Expected: Stale file handle */ + write(pipefd[1], "P", 1); + } else { + /* Other error */ + write(pipefd[1], "F", 1); + } + + close(pipefd[1]); + exit(0); + } + + /* Parent process */ + close(pipefd[1]); + ASSERT_EQ(read(pipefd[0], &result, 1), 1); + + waitpid(pid, &status, 0); + ASSERT_TRUE(WIFEXITED(status)); + ASSERT_EQ(WEXITSTATUS(status), 0); + + if (result == 'U') { + SKIP(free(handle); close(pipefd[0]); + return, "Cannot create new user namespace"); + } + if (result == 'M') { + SKIP(free(handle); close(pipefd[0]); + return, "Cannot set uid/gid mappings"); + } + if (result == 'N') { + SKIP(free(handle); close(pipefd[0]); + return, "Cannot create new mount namespace"); + } + + /* Should fail with ESTALE since we're in a different user namespace */ + ASSERT_EQ(result, 'P'); + + close(pipefd[0]); + free(handle); +} + +TEST(nsfs_user_cgroup_namespace_isolation) +{ + struct file_handle *handle; + int mount_id; + int ret; + int fd; + int ns_fd; + pid_t pid; + int status; + int pipefd[2]; + char result; + + handle = malloc(sizeof(*handle) + MAX_HANDLE_SZ); + ASSERT_NE(handle, NULL); + + /* Create pipe for communication */ + ASSERT_EQ(pipe(pipefd), 0); + + /* Get handle for current cgroup namespace */ + ns_fd = open("/proc/self/ns/cgroup", O_RDONLY); + if (ns_fd < 0) { + SKIP(free(handle); close(pipefd[0]); close(pipefd[1]); + return, "cgroup namespace not available"); + } + + handle->handle_bytes = MAX_HANDLE_SZ; + ret = name_to_handle_at(ns_fd, "", handle, &mount_id, AT_EMPTY_PATH); + if (ret < 0 && errno == EOPNOTSUPP) { + SKIP(free(handle); close(ns_fd); close(pipefd[0]); + close(pipefd[1]); + return, "nsfs doesn't support file handles"); + } + ASSERT_EQ(ret, 0); + close(ns_fd); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) { + /* Child process */ + close(pipefd[0]); + + /* First create new user namespace to drop privileges */ + ret = unshare(CLONE_NEWUSER); + if (ret < 0) { + write(pipefd[1], "U", + 1); /* Unable to create user namespace */ + close(pipefd[1]); + exit(0); + } + + /* Write uid/gid mappings to maintain some capabilities */ + int uid_map_fd = open("/proc/self/uid_map", O_WRONLY); + int gid_map_fd = open("/proc/self/gid_map", O_WRONLY); + int setgroups_fd = open("/proc/self/setgroups", O_WRONLY); + + if (uid_map_fd < 0 || gid_map_fd < 0 || setgroups_fd < 0) { + write(pipefd[1], "M", 1); /* Unable to set mappings */ + close(pipefd[1]); + exit(0); + } + + /* Disable setgroups to allow gid mapping */ + write(setgroups_fd, "deny", 4); + close(setgroups_fd); + + /* Map current uid/gid to root in the new namespace */ + char mapping[64]; + snprintf(mapping, sizeof(mapping), "0 %d 1", getuid()); + write(uid_map_fd, mapping, strlen(mapping)); + close(uid_map_fd); + + snprintf(mapping, sizeof(mapping), "0 %d 1", getgid()); + write(gid_map_fd, mapping, strlen(mapping)); + close(gid_map_fd); + + /* Now create new cgroup namespace */ + ret = unshare(CLONE_NEWCGROUP); + if (ret < 0) { + write(pipefd[1], "N", + 1); /* Unable to create cgroup namespace */ + close(pipefd[1]); + exit(0); + } + + /* Try to open parent's cgroup namespace handle from new user+cgroup namespace */ + fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_RDONLY); + + if (fd >= 0) { + /* Should NOT succeed - we're in a different user namespace */ + write(pipefd[1], "S", 1); /* Unexpected success */ + close(fd); + } else if (errno == ESTALE) { + /* Expected: Stale file handle */ + write(pipefd[1], "P", 1); + } else { + /* Other error */ + write(pipefd[1], "F", 1); + } + + close(pipefd[1]); + exit(0); + } + + /* Parent process */ + close(pipefd[1]); + ASSERT_EQ(read(pipefd[0], &result, 1), 1); + + waitpid(pid, &status, 0); + ASSERT_TRUE(WIFEXITED(status)); + ASSERT_EQ(WEXITSTATUS(status), 0); + + if (result == 'U') { + SKIP(free(handle); close(pipefd[0]); + return, "Cannot create new user namespace"); + } + if (result == 'M') { + SKIP(free(handle); close(pipefd[0]); + return, "Cannot set uid/gid mappings"); + } + if (result == 'N') { + SKIP(free(handle); close(pipefd[0]); + return, "Cannot create new cgroup namespace"); + } + + /* Should fail with ESTALE since we're in a different user namespace */ + ASSERT_EQ(result, 'P'); + + close(pipefd[0]); + free(handle); +} + +TEST(nsfs_user_pid_namespace_isolation) +{ + struct file_handle *handle; + int mount_id; + int ret; + int fd; + int ns_fd; + pid_t pid; + int status; + int pipefd[2]; + char result; + + handle = malloc(sizeof(*handle) + MAX_HANDLE_SZ); + ASSERT_NE(handle, NULL); + + /* Create pipe for communication */ + ASSERT_EQ(pipe(pipefd), 0); + + /* Get handle for current PID namespace */ + ns_fd = open("/proc/self/ns/pid", O_RDONLY); + ASSERT_GE(ns_fd, 0); + + handle->handle_bytes = MAX_HANDLE_SZ; + ret = name_to_handle_at(ns_fd, "", handle, &mount_id, AT_EMPTY_PATH); + if (ret < 0 && errno == EOPNOTSUPP) { + SKIP(free(handle); close(ns_fd); close(pipefd[0]); + close(pipefd[1]); + return, "nsfs doesn't support file handles"); + } + ASSERT_EQ(ret, 0); + close(ns_fd); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) { + /* Child process */ + close(pipefd[0]); + + /* First create new user namespace to drop privileges */ + ret = unshare(CLONE_NEWUSER); + if (ret < 0) { + write(pipefd[1], "U", + 1); /* Unable to create user namespace */ + close(pipefd[1]); + exit(0); + } + + /* Write uid/gid mappings to maintain some capabilities */ + int uid_map_fd = open("/proc/self/uid_map", O_WRONLY); + int gid_map_fd = open("/proc/self/gid_map", O_WRONLY); + int setgroups_fd = open("/proc/self/setgroups", O_WRONLY); + + if (uid_map_fd < 0 || gid_map_fd < 0 || setgroups_fd < 0) { + write(pipefd[1], "M", 1); /* Unable to set mappings */ + close(pipefd[1]); + exit(0); + } + + /* Disable setgroups to allow gid mapping */ + write(setgroups_fd, "deny", 4); + close(setgroups_fd); + + /* Map current uid/gid to root in the new namespace */ + char mapping[64]; + snprintf(mapping, sizeof(mapping), "0 %d 1", getuid()); + write(uid_map_fd, mapping, strlen(mapping)); + close(uid_map_fd); + + snprintf(mapping, sizeof(mapping), "0 %d 1", getgid()); + write(gid_map_fd, mapping, strlen(mapping)); + close(gid_map_fd); + + /* Now create new PID namespace - requires fork to take effect */ + ret = unshare(CLONE_NEWPID); + if (ret < 0) { + write(pipefd[1], "N", + 1); /* Unable to create PID namespace */ + close(pipefd[1]); + exit(0); + } + + /* Fork again for PID namespace to take effect */ + pid_t child_pid = fork(); + if (child_pid < 0) { + write(pipefd[1], "N", + 1); /* Unable to fork in PID namespace */ + close(pipefd[1]); + exit(0); + } + + if (child_pid == 0) { + /* Grandchild in new PID namespace */ + /* Try to open parent's PID namespace handle from new user+pid namespace */ + fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_RDONLY); + + if (fd >= 0) { + /* Should NOT succeed - we're in a different user namespace */ + write(pipefd[1], "S", + 1); /* Unexpected success */ + close(fd); + } else if (errno == ESTALE) { + /* Expected: Stale file handle */ + write(pipefd[1], "P", 1); + } else { + /* Other error */ + write(pipefd[1], "F", 1); + } + + close(pipefd[1]); + exit(0); + } + + /* Wait for grandchild */ + waitpid(child_pid, NULL, 0); + exit(0); + } + + /* Parent process */ + close(pipefd[1]); + ASSERT_EQ(read(pipefd[0], &result, 1), 1); + + waitpid(pid, &status, 0); + ASSERT_TRUE(WIFEXITED(status)); + ASSERT_EQ(WEXITSTATUS(status), 0); + + if (result == 'U') { + SKIP(free(handle); close(pipefd[0]); + return, "Cannot create new user namespace"); + } + if (result == 'M') { + SKIP(free(handle); close(pipefd[0]); + return, "Cannot set uid/gid mappings"); + } + if (result == 'N') { + SKIP(free(handle); close(pipefd[0]); + return, "Cannot create new PID namespace"); + } + + /* Should fail with ESTALE since we're in a different user namespace */ + ASSERT_EQ(result, 'P'); + + close(pipefd[0]); + free(handle); +} + +TEST(nsfs_user_time_namespace_isolation) +{ + struct file_handle *handle; + int mount_id; + int ret; + int fd; + int ns_fd; + pid_t pid; + int status; + int pipefd[2]; + char result; + + handle = malloc(sizeof(*handle) + MAX_HANDLE_SZ); + ASSERT_NE(handle, NULL); + + /* Create pipe for communication */ + ASSERT_EQ(pipe(pipefd), 0); + + /* Get handle for current time namespace */ + ns_fd = open("/proc/self/ns/time", O_RDONLY); + if (ns_fd < 0) { + SKIP(free(handle); close(pipefd[0]); close(pipefd[1]); + return, "time namespace not available"); + } + + handle->handle_bytes = MAX_HANDLE_SZ; + ret = name_to_handle_at(ns_fd, "", handle, &mount_id, AT_EMPTY_PATH); + if (ret < 0 && errno == EOPNOTSUPP) { + SKIP(free(handle); close(ns_fd); close(pipefd[0]); + close(pipefd[1]); + return, "nsfs doesn't support file handles"); + } + ASSERT_EQ(ret, 0); + close(ns_fd); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) { + /* Child process */ + close(pipefd[0]); + + /* First create new user namespace to drop privileges */ + ret = unshare(CLONE_NEWUSER); + if (ret < 0) { + write(pipefd[1], "U", + 1); /* Unable to create user namespace */ + close(pipefd[1]); + exit(0); + } + + /* Write uid/gid mappings to maintain some capabilities */ + int uid_map_fd = open("/proc/self/uid_map", O_WRONLY); + int gid_map_fd = open("/proc/self/gid_map", O_WRONLY); + int setgroups_fd = open("/proc/self/setgroups", O_WRONLY); + + if (uid_map_fd < 0 || gid_map_fd < 0 || setgroups_fd < 0) { + write(pipefd[1], "M", 1); /* Unable to set mappings */ + close(pipefd[1]); + exit(0); + } + + /* Disable setgroups to allow gid mapping */ + write(setgroups_fd, "deny", 4); + close(setgroups_fd); + + /* Map current uid/gid to root in the new namespace */ + char mapping[64]; + snprintf(mapping, sizeof(mapping), "0 %d 1", getuid()); + write(uid_map_fd, mapping, strlen(mapping)); + close(uid_map_fd); + + snprintf(mapping, sizeof(mapping), "0 %d 1", getgid()); + write(gid_map_fd, mapping, strlen(mapping)); + close(gid_map_fd); + + /* Now create new time namespace - requires fork to take effect */ + ret = unshare(CLONE_NEWTIME); + if (ret < 0) { + write(pipefd[1], "N", + 1); /* Unable to create time namespace */ + close(pipefd[1]); + exit(0); + } + + /* Fork again for time namespace to take effect */ + pid_t child_pid = fork(); + if (child_pid < 0) { + write(pipefd[1], "N", + 1); /* Unable to fork in time namespace */ + close(pipefd[1]); + exit(0); + } + + if (child_pid == 0) { + /* Grandchild in new time namespace */ + /* Try to open parent's time namespace handle from new user+time namespace */ + fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_RDONLY); + + if (fd >= 0) { + /* Should NOT succeed - we're in a different user namespace */ + write(pipefd[1], "S", + 1); /* Unexpected success */ + close(fd); + } else if (errno == ESTALE) { + /* Expected: Stale file handle */ + write(pipefd[1], "P", 1); + } else { + /* Other error */ + write(pipefd[1], "F", 1); + } + + close(pipefd[1]); + exit(0); + } + + /* Wait for grandchild */ + waitpid(child_pid, NULL, 0); + exit(0); + } + + /* Parent process */ + close(pipefd[1]); + ASSERT_EQ(read(pipefd[0], &result, 1), 1); + + waitpid(pid, &status, 0); + ASSERT_TRUE(WIFEXITED(status)); + ASSERT_EQ(WEXITSTATUS(status), 0); + + if (result == 'U') { + SKIP(free(handle); close(pipefd[0]); + return, "Cannot create new user namespace"); + } + if (result == 'M') { + SKIP(free(handle); close(pipefd[0]); + return, "Cannot set uid/gid mappings"); + } + if (result == 'N') { + SKIP(free(handle); close(pipefd[0]); + return, "Cannot create new time namespace"); + } + + /* Should fail with ESTALE since we're in a different user namespace */ + ASSERT_EQ(result, 'P'); + + close(pipefd[0]); + free(handle); +} + +TEST(nsfs_open_flags) +{ + struct file_handle *handle; + int mount_id; + int ret; + int fd; + int ns_fd; + + handle = malloc(sizeof(*handle) + MAX_HANDLE_SZ); + ASSERT_NE(handle, NULL); + + /* Open a namespace file descriptor */ + ns_fd = open("/proc/self/ns/net", O_RDONLY); + ASSERT_GE(ns_fd, 0); + + /* Get handle for the namespace */ + handle->handle_bytes = MAX_HANDLE_SZ; + ret = name_to_handle_at(ns_fd, "", handle, &mount_id, AT_EMPTY_PATH); + if (ret < 0 && errno == EOPNOTSUPP) { + SKIP(free(handle); close(ns_fd); + return, "nsfs doesn't support file handles"); + } + ASSERT_EQ(ret, 0); + ASSERT_GT(handle->handle_bytes, 0); + + /* Test invalid flags that should fail */ + fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_WRONLY); + ASSERT_LT(fd, 0); + ASSERT_EQ(errno, EPERM); + + fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_RDWR); + ASSERT_LT(fd, 0); + ASSERT_EQ(errno, EPERM); + + fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_TRUNC); + ASSERT_LT(fd, 0); + ASSERT_EQ(errno, EPERM); + + fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_DIRECT); + ASSERT_LT(fd, 0); + ASSERT_EQ(errno, EINVAL); + + fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_TMPFILE); + ASSERT_LT(fd, 0); + ASSERT_EQ(errno, EINVAL); + + fd = open_by_handle_at(FD_NSFS_ROOT, handle, O_DIRECTORY); + ASSERT_LT(fd, 0); + ASSERT_EQ(errno, ENOTDIR); + + close(ns_fd); + free(handle); +} + +TEST_HARNESS_MAIN