-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
/***
This file is part of systemd.
#include <unistd.h>
#include <linux/fs.h>
+#include "alloc-util.h"
#include "dev-setup.h"
#include "fd-util.h"
+#include "fs-util.h"
#include "loopback-setup.h"
#include "missing.h"
#include "mkdir.h"
+#include "mount-util.h"
#include "namespace.h"
#include "path-util.h"
#include "selinux-util.h"
#include "socket-util.h"
+#include "string-table.h"
#include "string-util.h"
#include "strv.h"
+#include "umask-util.h"
+#include "user-util.h"
#include "util.h"
+#define DEV_MOUNT_OPTIONS (MS_NOSUID|MS_STRICTATIME|MS_NOEXEC)
+
typedef enum MountMode {
/* This is ordered by priority! */
INACCESSIBLE,
PRIVATE_TMP,
PRIVATE_VAR_TMP,
PRIVATE_DEV,
- PRIVATE_BUS_ENDPOINT,
- READWRITE
+ READWRITE,
} MountMode;
typedef struct BindMount {
- const char *path;
- MountMode mode;
- bool done;
- bool ignore;
+ const char *path_const; /* Memory allocated on stack or static */
+ MountMode mode:6;
+ bool ignore:1; /* Ignore if path does not exist? */
+ bool has_prefix:1; /* Already is prefixed by the root dir? */
+ char *path_malloc; /* Use this instead of 'path' if we had to allocate memory */
} BindMount;
-static int append_mounts(BindMount **p, char **strv, MountMode mode) {
+/*
+ * The following Protect tables are to protect paths and mark some of them
+ * READONLY, in case a path is covered by an option from another table, then
+ * it is marked READWRITE in the current one, and the more restrictive mode is
+ * applied from that other table. This way all options can be combined in a
+ * safe and comprehensible way for users.
+ */
+
+/* ProtectKernelTunables= option and the related filesystem APIs */
+static const BindMount protect_kernel_tunables_table[] = {
+ { "/proc/sys", READONLY, false },
+ { "/proc/sysrq-trigger", READONLY, true },
+ { "/proc/latency_stats", READONLY, true },
+ { "/proc/mtrr", READONLY, true },
+ { "/proc/apm", READONLY, true }, /* Obsolete API, there's no point in permitting access to this, ever */
+ { "/proc/acpi", READONLY, true },
+ { "/proc/timer_stats", READONLY, true },
+ { "/proc/asound", READONLY, true },
+ { "/proc/bus", READONLY, true },
+ { "/proc/fs", READONLY, true },
+ { "/proc/irq", READONLY, true },
+ { "/sys", READONLY, false },
+ { "/sys/kernel/debug", READONLY, true },
+ { "/sys/kernel/tracing", READONLY, true },
+ { "/sys/fs/cgroup", READWRITE, false }, /* READONLY is set by ProtectControlGroups= option */
+};
+
+/* ProtectKernelModules= option */
+static const BindMount protect_kernel_modules_table[] = {
+#ifdef HAVE_SPLIT_USR
+ { "/lib/modules", INACCESSIBLE, true },
+#endif
+ { "/usr/lib/modules", INACCESSIBLE, true },
+};
+
+/*
+ * ProtectHome=read-only table, protect $HOME and $XDG_RUNTIME_DIR and rest of
+ * system should be protected by ProtectSystem=
+ */
+static const BindMount protect_home_read_only_table[] = {
+ { "/home", READONLY, true },
+ { "/run/user", READONLY, true },
+ { "/root", READONLY, true },
+};
+
+/* ProtectHome=yes table */
+static const BindMount protect_home_yes_table[] = {
+ { "/home", INACCESSIBLE, true },
+ { "/run/user", INACCESSIBLE, true },
+ { "/root", INACCESSIBLE, true },
+};
+
+/* ProtectSystem=yes table */
+static const BindMount protect_system_yes_table[] = {
+ { "/usr", READONLY, false },
+ { "/boot", READONLY, true },
+ { "/efi", READONLY, true },
+};
+
+/* ProtectSystem=full includes ProtectSystem=yes */
+static const BindMount protect_system_full_table[] = {
+ { "/usr", READONLY, false },
+ { "/boot", READONLY, true },
+ { "/efi", READONLY, true },
+ { "/etc", READONLY, false },
+};
+
+/*
+ * ProtectSystem=strict table. In this strict mode, we mount everything
+ * read-only, except for /proc, /dev, /sys which are the kernel API VFS,
+ * which are left writable, but PrivateDevices= + ProtectKernelTunables=
+ * protect those, and these options should be fully orthogonal.
+ * (And of course /home and friends are also left writable, as ProtectHome=
+ * shall manage those, orthogonally).
+ */
+static const BindMount protect_system_strict_table[] = {
+ { "/", READONLY, false },
+ { "/proc", READWRITE, false }, /* ProtectKernelTunables= */
+ { "/sys", READWRITE, false }, /* ProtectKernelTunables= */
+ { "/dev", READWRITE, false }, /* PrivateDevices= */
+ { "/home", READWRITE, true }, /* ProtectHome= */
+ { "/run/user", READWRITE, true }, /* ProtectHome= */
+ { "/root", READWRITE, true }, /* ProtectHome= */
+};
+
+static const char *bind_mount_path(const BindMount *p) {
+ assert(p);
+
+ /* Returns the path of this bind mount. If the malloc()-allocated ->path_buffer field is set we return that,
+ * otherwise the stack/static ->path field is returned. */
+
+ return p->path_malloc ?: p->path_const;
+}
+
+static int append_access_mounts(BindMount **p, char **strv, MountMode mode) {
char **i;
assert(p);
- STRV_FOREACH(i, strv) {
+ /* Adds a list of user-supplied READWRITE/READONLY/INACCESSIBLE entries */
- (*p)->ignore = false;
- (*p)->done = false;
+ STRV_FOREACH(i, strv) {
+ bool ignore = false, needs_prefix = false;
+ const char *e = *i;
- if ((mode == INACCESSIBLE || mode == READONLY || mode == READWRITE) && (*i)[0] == '-') {
- (*p)->ignore = true;
- (*i)++;
+ /* Look for any prefixes */
+ if (startswith(e, "-")) {
+ e++;
+ ignore = true;
+ }
+ if (startswith(e, "+")) {
+ e++;
+ needs_prefix = true;
}
- if (!path_is_absolute(*i))
+ if (!path_is_absolute(e))
return -EINVAL;
- (*p)->path = *i;
- (*p)->mode = mode;
- (*p)++;
+ *((*p)++) = (BindMount) {
+ .path_const = e,
+ .mode = mode,
+ .ignore = ignore,
+ .has_prefix = !needs_prefix,
+ };
}
return 0;
}
+static int append_static_mounts(BindMount **p, const BindMount *mounts, unsigned n, bool ignore_protect) {
+ unsigned i;
+
+ assert(p);
+ assert(mounts);
+
+ /* Adds a list of static pre-defined entries */
+
+ for (i = 0; i < n; i++)
+ *((*p)++) = (BindMount) {
+ .path_const = bind_mount_path(mounts+i),
+ .mode = mounts[i].mode,
+ .ignore = mounts[i].ignore || ignore_protect,
+ };
+
+ return 0;
+}
+
+static int append_protect_home(BindMount **p, ProtectHome protect_home, bool ignore_protect) {
+ assert(p);
+
+ switch (protect_home) {
+
+ case PROTECT_HOME_NO:
+ return 0;
+
+ case PROTECT_HOME_READ_ONLY:
+ return append_static_mounts(p, protect_home_read_only_table, ELEMENTSOF(protect_home_read_only_table), ignore_protect);
+
+ case PROTECT_HOME_YES:
+ return append_static_mounts(p, protect_home_yes_table, ELEMENTSOF(protect_home_yes_table), ignore_protect);
+
+ default:
+ assert_not_reached("Unexpected ProtectHome= value");
+ }
+}
+
+static int append_protect_system(BindMount **p, ProtectSystem protect_system, bool ignore_protect) {
+ assert(p);
+
+ switch (protect_system) {
+
+ case PROTECT_SYSTEM_NO:
+ return 0;
+
+ case PROTECT_SYSTEM_STRICT:
+ return append_static_mounts(p, protect_system_strict_table, ELEMENTSOF(protect_system_strict_table), ignore_protect);
+
+ case PROTECT_SYSTEM_YES:
+ return append_static_mounts(p, protect_system_yes_table, ELEMENTSOF(protect_system_yes_table), ignore_protect);
+
+ case PROTECT_SYSTEM_FULL:
+ return append_static_mounts(p, protect_system_full_table, ELEMENTSOF(protect_system_full_table), ignore_protect);
+
+ default:
+ assert_not_reached("Unexpected ProtectSystem= value");
+ }
+}
+
static int mount_path_compare(const void *a, const void *b) {
const BindMount *p = a, *q = b;
int d;
- d = path_compare(p->path, q->path);
+ /* If the paths are not equal, then order prefixes first */
+ d = path_compare(bind_mount_path(p), bind_mount_path(q));
+ if (d != 0)
+ return d;
+
+ /* If the paths are equal, check the mode */
+ if (p->mode < q->mode)
+ return -1;
+
+ if (p->mode > q->mode)
+ return 1;
+
+ return 0;
+}
- if (d == 0) {
- /* If the paths are equal, check the mode */
- if (p->mode < q->mode)
- return -1;
+static int prefix_where_needed(BindMount *m, unsigned n, const char *root_directory) {
+ unsigned i;
- if (p->mode > q->mode)
- return 1;
+ /* Prefixes all paths in the bind mount table with the root directory if it is specified and the entry needs
+ * that. */
+ if (!root_directory)
return 0;
+
+ for (i = 0; i < n; i++) {
+ char *s;
+
+ if (m[i].has_prefix)
+ continue;
+
+ s = prefix_root(root_directory, bind_mount_path(m+i));
+ if (!s)
+ return -ENOMEM;
+
+ free(m[i].path_malloc);
+ m[i].path_malloc = s;
+
+ m[i].has_prefix = true;
}
- /* If the paths are not equal, then order prefixes first */
- return d;
+ return 0;
}
static void drop_duplicates(BindMount *m, unsigned *n) {
assert(m);
assert(n);
- for (f = m, t = m, previous = NULL; f < m+*n; f++) {
+ /* Drops duplicate entries. Expects that the array is properly ordered already. */
+
+ for (f = m, t = m, previous = NULL; f < m + *n; f++) {
- /* The first one wins */
- if (previous && path_equal(f->path, previous->path))
+ /* The first one wins (which is the one with the more restrictive mode), see mount_path_compare()
+ * above. */
+ if (previous && path_equal(bind_mount_path(f), bind_mount_path(previous))) {
+ log_debug("%s is duplicate.", bind_mount_path(f));
+ f->path_malloc = mfree(f->path_malloc);
continue;
+ }
*t = *f;
-
previous = t;
+ t++;
+ }
+
+ *n = t - m;
+}
+
+static void drop_inaccessible(BindMount *m, unsigned *n) {
+ BindMount *f, *t;
+ const char *clear = NULL;
+
+ assert(m);
+ assert(n);
+
+ /* Drops all entries obstructed by another entry further up the tree. Expects that the array is properly
+ * ordered already. */
+
+ for (f = m, t = m; f < m + *n; f++) {
+
+ /* If we found a path set for INACCESSIBLE earlier, and this entry has it as prefix we should drop
+ * it, as inaccessible paths really should drop the entire subtree. */
+ if (clear && path_startswith(bind_mount_path(f), clear)) {
+ log_debug("%s is masked by %s.", bind_mount_path(f), clear);
+ f->path_malloc = mfree(f->path_malloc);
+ continue;
+ }
+
+ clear = f->mode == INACCESSIBLE ? bind_mount_path(f) : NULL;
+
+ *t = *f;
+ t++;
+ }
+
+ *n = t - m;
+}
+
+static void drop_nop(BindMount *m, unsigned *n) {
+ BindMount *f, *t;
+
+ assert(m);
+ assert(n);
+
+ /* Drops all entries which have an immediate parent that has the same type, as they are redundant. Assumes the
+ * list is ordered by prefixes. */
+
+ for (f = m, t = m; f < m + *n; f++) {
+
+ /* Only suppress such subtrees for READONLY and READWRITE entries */
+ if (IN_SET(f->mode, READONLY, READWRITE)) {
+ BindMount *p;
+ bool found = false;
+
+ /* Now let's find the first parent of the entry we are looking at. */
+ for (p = t-1; p >= m; p--) {
+ if (path_startswith(bind_mount_path(f), bind_mount_path(p))) {
+ found = true;
+ break;
+ }
+ }
+
+ /* We found it, let's see if it's the same mode, if so, we can drop this entry */
+ if (found && p->mode == f->mode) {
+ log_debug("%s is redundant by %s", bind_mount_path(f), bind_mount_path(p));
+ f->path_malloc = mfree(f->path_malloc);
+ continue;
+ }
+ }
+
+ *t = *f;
+ t++;
+ }
+
+ *n = t - m;
+}
+
+static void drop_outside_root(const char *root_directory, BindMount *m, unsigned *n) {
+ BindMount *f, *t;
+
+ assert(m);
+ assert(n);
+
+ /* Nothing to do */
+ if (!root_directory)
+ return;
+
+ /* Drops all mounts that are outside of the root directory. */
+
+ for (f = m, t = m; f < m + *n; f++) {
+
+ if (!path_startswith(bind_mount_path(f), root_directory)) {
+ log_debug("%s is outside of root directory.", bind_mount_path(f));
+ f->path_malloc = mfree(f->path_malloc);
+ continue;
+ }
+ *t = *f;
t++;
}
dev = strjoina(temporary_mount, "/dev");
(void) mkdir(dev, 0755);
- if (mount("tmpfs", dev, "tmpfs", MS_NOSUID|MS_STRICTATIME, "mode=755") < 0) {
+ if (mount("tmpfs", dev, "tmpfs", DEV_MOUNT_OPTIONS, "mode=755") < 0) {
r = -errno;
goto fail;
}
* missing when the service is started with RootDirectory. This is
* consistent with mount units creating the mount points when missing.
*/
- (void) mkdir_p_label(m->path, 0755);
+ (void) mkdir_p_label(bind_mount_path(m), 0755);
- if (mount(dev, m->path, NULL, MS_MOVE, NULL) < 0) {
+ /* Unmount everything in old /dev */
+ umount_recursive(bind_mount_path(m), 0);
+ if (mount(dev, bind_mount_path(m), NULL, MS_MOVE, NULL) < 0) {
r = -errno;
goto fail;
}
return r;
}
-static int mount_kdbus(BindMount *m) {
-
- char temporary_mount[] = "/tmp/kdbus-dev-XXXXXX";
- _cleanup_free_ char *basepath = NULL;
- _cleanup_umask_ mode_t u;
- char *busnode = NULL, *root;
- struct stat st;
- int r;
-
- assert(m);
-
- u = umask(0000);
-
- if (!mkdtemp(temporary_mount))
- return log_error_errno(errno, "Failed create temp dir: %m");
-
- root = strjoina(temporary_mount, "/kdbus");
- (void) mkdir(root, 0755);
- if (mount("tmpfs", root, "tmpfs", MS_NOSUID|MS_STRICTATIME, "mode=777") < 0) {
- r = -errno;
- goto fail;
- }
-
- /* create a new /dev/null dev node copy so we have some fodder to
- * bind-mount the custom endpoint over. */
- if (stat("/dev/null", &st) < 0) {
- r = log_error_errno(errno, "Failed to stat /dev/null: %m");
- goto fail;
- }
-
- busnode = strjoina(root, "/bus");
- if (mknod(busnode, (st.st_mode & ~07777) | 0600, st.st_rdev) < 0) {
- r = log_error_errno(errno, "mknod() for %s failed: %m",
- busnode);
- goto fail;
- }
-
- r = mount(m->path, busnode, NULL, MS_BIND, NULL);
- if (r < 0) {
- r = log_error_errno(errno, "bind mount of %s failed: %m",
- m->path);
- goto fail;
- }
-
- basepath = dirname_malloc(m->path);
- if (!basepath) {
- r = -ENOMEM;
- goto fail;
- }
-
- if (mount(root, basepath, NULL, MS_MOVE, NULL) < 0) {
- r = log_error_errno(errno, "bind mount of %s failed: %m",
- basepath);
- goto fail;
- }
-
- rmdir(temporary_mount);
- return 0;
-
-fail:
- if (busnode) {
- umount(busnode);
- unlink(busnode);
- }
-
- umount(root);
- rmdir(root);
- rmdir(temporary_mount);
-
- return r;
-}
-
static int apply_mount(
BindMount *m,
const char *tmp_dir,
assert(m);
+ log_debug("Applying namespace mount on %s", bind_mount_path(m));
+
switch (m->mode) {
- case INACCESSIBLE:
+ case INACCESSIBLE: {
+ struct stat target;
/* First, get rid of everything that is below if there
* is anything... Then, overmount it with an
- * inaccessible directory. */
- umount_recursive(m->path, 0);
+ * inaccessible path. */
+ (void) umount_recursive(bind_mount_path(m), 0);
- what = "/run/systemd/inaccessible";
+ if (lstat(bind_mount_path(m), &target) < 0)
+ return log_debug_errno(errno, "Failed to lstat() %s to determine what to mount over it: %m", bind_mount_path(m));
+
+ what = mode_to_inaccessible_node(target.st_mode);
+ if (!what) {
+ log_debug("File type not supported for inaccessible mounts. Note that symlinks are not allowed");
+ return -ELOOP;
+ }
break;
+ }
case READONLY:
case READWRITE:
- /* Nothing to mount here, we just later toggle the
- * MS_RDONLY bit for the mount point */
- return 0;
+
+ r = path_is_mount_point(bind_mount_path(m), NULL, 0);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to determine whether %s is already a mount point: %m", bind_mount_path(m));
+ if (r > 0) /* Nothing to do here, it is already a mount. We just later toggle the MS_RDONLY bit for the mount point if needed. */
+ return 0;
+ /* This isn't a mount point yet, let's make it one. */
+ what = bind_mount_path(m);
+ break;
case PRIVATE_TMP:
what = tmp_dir;
case PRIVATE_DEV:
return mount_dev(m);
- case PRIVATE_BUS_ENDPOINT:
- return mount_kdbus(m);
-
default:
assert_not_reached("Unknown mode");
}
assert(what);
- r = mount(what, m->path, NULL, MS_BIND|MS_REC, NULL);
- if (r >= 0)
- log_debug("Successfully mounted %s to %s", what, m->path);
- else if (m->ignore && errno == ENOENT)
+ if (mount(what, bind_mount_path(m), NULL, MS_BIND|MS_REC, NULL) < 0)
+ return log_debug_errno(errno, "Failed to mount %s to %s: %m", what, bind_mount_path(m));
+
+ log_debug("Successfully mounted %s to %s", what, bind_mount_path(m));
+ return 0;
+}
+
+static int make_read_only(BindMount *m, char **blacklist) {
+ int r = 0;
+
+ assert(m);
+
+ if (IN_SET(m->mode, INACCESSIBLE, READONLY))
+ r = bind_remount_recursive(bind_mount_path(m), true, blacklist);
+ else if (m->mode == PRIVATE_DEV) { /* Can be readonly but the submounts can't*/
+ if (mount(NULL, bind_mount_path(m), NULL, MS_REMOUNT|DEV_MOUNT_OPTIONS|MS_RDONLY, NULL) < 0)
+ r = -errno;
+ } else
return 0;
+ /* Not that we only turn on the MS_RDONLY flag here, we never turn it off. Something that was marked read-only
+ * already stays this way. This improves compatibility with container managers, where we won't attempt to undo
+ * read-only mounts already applied. */
+
return r;
}
-static int make_read_only(BindMount *m) {
- int r;
+/* Chase symlinks and remove failed paths from mounts */
+static int chase_all_symlinks(const char *root_directory, BindMount *m, unsigned *n) {
+ BindMount *f, *t;
+ int r = 0;
assert(m);
+ assert(n);
- if (IN_SET(m->mode, INACCESSIBLE, READONLY))
- r = bind_remount_recursive(m->path, true);
- else if (IN_SET(m->mode, READWRITE, PRIVATE_TMP, PRIVATE_VAR_TMP, PRIVATE_DEV))
- r = bind_remount_recursive(m->path, false);
- else
- r = 0;
+ /* Since mount() will always follow symlinks and we need to take the different root directory into account we
+ * chase the symlinks on our own first. This call wil do so for all entries and remove all entries where we
+ * can't resolve the path, and which have been marked for such removal. */
- if (m->ignore && r == -ENOENT)
- return 0;
+ for (f = m, t = m; f < m + *n; f++) {
+ _cleanup_free_ char *chased = NULL;
+ int k;
+
+ k = chase_symlinks(bind_mount_path(f), root_directory, &chased);
+ if (k < 0) {
+ /* Get only real errors */
+ if (r >= 0 && (k != -ENOENT || !f->ignore))
+ r = k;
+
+ /* Doesn't exist or failed? Then remove it and continue! */
+ log_debug_errno(k, "Failed to chase symlinks for %s: %m", bind_mount_path(f));
+ f->path_malloc = mfree(f->path_malloc);
+ continue;
+ }
+
+ if (!path_equal(bind_mount_path(f), chased)) {
+ log_debug("Chased %s → %s", bind_mount_path(f), chased);
+ free(f->path_malloc);
+ f->path_malloc = chased;
+ chased = NULL;
+ }
+
+ *t = *f;
+ t++;
+ }
+
+ *n = t - m;
return r;
}
+static unsigned namespace_calculate_mounts(
+ const NameSpaceInfo *ns_info,
+ char** read_write_paths,
+ char** read_only_paths,
+ char** inaccessible_paths,
+ const char* tmp_dir,
+ const char* var_tmp_dir,
+ ProtectHome protect_home,
+ ProtectSystem protect_system) {
+
+ unsigned protect_home_cnt;
+ unsigned protect_system_cnt =
+ (protect_system == PROTECT_SYSTEM_STRICT ?
+ ELEMENTSOF(protect_system_strict_table) :
+ ((protect_system == PROTECT_SYSTEM_FULL) ?
+ ELEMENTSOF(protect_system_full_table) :
+ ((protect_system == PROTECT_SYSTEM_YES) ?
+ ELEMENTSOF(protect_system_yes_table) : 0)));
+
+ protect_home_cnt =
+ (protect_home == PROTECT_HOME_YES ?
+ ELEMENTSOF(protect_home_yes_table) :
+ ((protect_home == PROTECT_HOME_READ_ONLY) ?
+ ELEMENTSOF(protect_home_read_only_table) : 0));
+
+ return !!tmp_dir + !!var_tmp_dir +
+ strv_length(read_write_paths) +
+ strv_length(read_only_paths) +
+ strv_length(inaccessible_paths) +
+ ns_info->private_dev +
+ (ns_info->protect_kernel_tunables ? ELEMENTSOF(protect_kernel_tunables_table) : 0) +
+ (ns_info->protect_control_groups ? 1 : 0) +
+ (ns_info->protect_kernel_modules ? ELEMENTSOF(protect_kernel_modules_table) : 0) +
+ protect_home_cnt + protect_system_cnt;
+}
+
int setup_namespace(
const char* root_directory,
- char** read_write_dirs,
- char** read_only_dirs,
- char** inaccessible_dirs,
+ const NameSpaceInfo *ns_info,
+ char** read_write_paths,
+ char** read_only_paths,
+ char** inaccessible_paths,
const char* tmp_dir,
const char* var_tmp_dir,
- const char* bus_endpoint_path,
- bool private_dev,
ProtectHome protect_home,
ProtectSystem protect_system,
unsigned long mount_flags) {
BindMount *m, *mounts = NULL;
- unsigned n;
+ bool make_slave = false;
+ unsigned n_mounts;
int r = 0;
if (mount_flags == 0)
mount_flags = MS_SHARED;
- if (unshare(CLONE_NEWNS) < 0)
- return -errno;
+ n_mounts = namespace_calculate_mounts(ns_info,
+ read_write_paths,
+ read_only_paths,
+ inaccessible_paths,
+ tmp_dir, var_tmp_dir,
+ protect_home, protect_system);
+
+ /* Set mount slave mode */
+ if (root_directory || n_mounts > 0)
+ make_slave = true;
- n = !!tmp_dir + !!var_tmp_dir + !!bus_endpoint_path +
- strv_length(read_write_dirs) +
- strv_length(read_only_dirs) +
- strv_length(inaccessible_dirs) +
- private_dev +
- (protect_home != PROTECT_HOME_NO ? 3 : 0) +
- (protect_system != PROTECT_SYSTEM_NO ? 2 : 0) +
- (protect_system == PROTECT_SYSTEM_FULL ? 1 : 0);
-
- if (n > 0) {
- m = mounts = (BindMount *) alloca0(n * sizeof(BindMount));
- r = append_mounts(&m, read_write_dirs, READWRITE);
+ if (n_mounts > 0) {
+ m = mounts = (BindMount *) alloca0(n_mounts * sizeof(BindMount));
+ r = append_access_mounts(&m, read_write_paths, READWRITE);
if (r < 0)
- return r;
+ goto finish;
- r = append_mounts(&m, read_only_dirs, READONLY);
+ r = append_access_mounts(&m, read_only_paths, READONLY);
if (r < 0)
- return r;
+ goto finish;
- r = append_mounts(&m, inaccessible_dirs, INACCESSIBLE);
+ r = append_access_mounts(&m, inaccessible_paths, INACCESSIBLE);
if (r < 0)
- return r;
+ goto finish;
if (tmp_dir) {
- m->path = prefix_roota(root_directory, "/tmp");
- m->mode = PRIVATE_TMP;
- m++;
+ *(m++) = (BindMount) {
+ .path_const = "/tmp",
+ .mode = PRIVATE_TMP,
+ };
}
if (var_tmp_dir) {
- m->path = prefix_roota(root_directory, "/var/tmp");
- m->mode = PRIVATE_VAR_TMP;
- m++;
+ *(m++) = (BindMount) {
+ .path_const = "/var/tmp",
+ .mode = PRIVATE_VAR_TMP,
+ };
+ }
+
+ if (ns_info->private_dev) {
+ *(m++) = (BindMount) {
+ .path_const = "/dev",
+ .mode = PRIVATE_DEV,
+ };
}
- if (private_dev) {
- m->path = prefix_roota(root_directory, "/dev");
- m->mode = PRIVATE_DEV;
- m++;
+ if (ns_info->protect_kernel_tunables) {
+ r = append_static_mounts(&m, protect_kernel_tunables_table, ELEMENTSOF(protect_kernel_tunables_table), ns_info->ignore_protect_paths);
+ if (r < 0)
+ goto finish;
}
- if (bus_endpoint_path) {
- m->path = prefix_roota(root_directory, bus_endpoint_path);
- m->mode = PRIVATE_BUS_ENDPOINT;
- m++;
+ if (ns_info->protect_kernel_modules) {
+ r = append_static_mounts(&m, protect_kernel_modules_table, ELEMENTSOF(protect_kernel_modules_table), ns_info->ignore_protect_paths);
+ if (r < 0)
+ goto finish;
}
- if (protect_home != PROTECT_HOME_NO) {
- const char *home_dir, *run_user_dir, *root_dir;
+ if (ns_info->protect_control_groups) {
+ *(m++) = (BindMount) {
+ .path_const = "/sys/fs/cgroup",
+ .mode = READONLY,
+ };
+ }
- home_dir = prefix_roota(root_directory, "/home");
- home_dir = strjoina("-", home_dir);
- run_user_dir = prefix_roota(root_directory, "/run/user");
- run_user_dir = strjoina("-", run_user_dir);
- root_dir = prefix_roota(root_directory, "/root");
- root_dir = strjoina("-", root_dir);
+ r = append_protect_home(&m, protect_home, ns_info->ignore_protect_paths);
+ if (r < 0)
+ goto finish;
- r = append_mounts(&m, STRV_MAKE(home_dir, run_user_dir, root_dir),
- protect_home == PROTECT_HOME_READ_ONLY ? READONLY : INACCESSIBLE);
- if (r < 0)
- return r;
- }
+ r = append_protect_system(&m, protect_system, false);
+ if (r < 0)
+ goto finish;
- if (protect_system != PROTECT_SYSTEM_NO) {
- const char *usr_dir, *boot_dir, *etc_dir;
+ assert(mounts + n_mounts == m);
- usr_dir = prefix_roota(root_directory, "/usr");
- boot_dir = prefix_roota(root_directory, "/boot");
- boot_dir = strjoina("-", boot_dir);
- etc_dir = prefix_roota(root_directory, "/etc");
+ /* Prepend the root directory where that's necessary */
+ r = prefix_where_needed(mounts, n_mounts, root_directory);
+ if (r < 0)
+ goto finish;
- r = append_mounts(&m, protect_system == PROTECT_SYSTEM_FULL
- ? STRV_MAKE(usr_dir, boot_dir, etc_dir)
- : STRV_MAKE(usr_dir, boot_dir), READONLY);
- if (r < 0)
- return r;
- }
+ /* Resolve symlinks manually first, as mount() will always follow them relative to the host's
+ * root. Moreover we want to suppress duplicates based on the resolved paths. This of course is a bit
+ * racy. */
+ r = chase_all_symlinks(root_directory, mounts, &n_mounts);
+ if (r < 0)
+ goto finish;
- assert(mounts + n == m);
+ qsort(mounts, n_mounts, sizeof(BindMount), mount_path_compare);
- qsort(mounts, n, sizeof(BindMount), mount_path_compare);
- drop_duplicates(mounts, &n);
+ drop_duplicates(mounts, &n_mounts);
+ drop_outside_root(root_directory, mounts, &n_mounts);
+ drop_inaccessible(mounts, &n_mounts);
+ drop_nop(mounts, &n_mounts);
+ }
+
+ if (unshare(CLONE_NEWNS) < 0) {
+ r = -errno;
+ goto finish;
}
- if (n > 0 || root_directory) {
+ if (make_slave) {
/* Remount / as SLAVE so that nothing now mounted in the namespace
shows up in the parent */
- if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) < 0)
- return -errno;
+ if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) < 0) {
+ r = -errno;
+ goto finish;
+ }
}
if (root_directory) {
- /* Turn directory into bind mount */
- if (mount(root_directory, root_directory, NULL, MS_BIND|MS_REC, NULL) < 0)
- return -errno;
+ /* Turn directory into bind mount, if it isn't one yet */
+ r = path_is_mount_point(root_directory, NULL, AT_SYMLINK_FOLLOW);
+ if (r < 0)
+ goto finish;
+ if (r == 0) {
+ if (mount(root_directory, root_directory, NULL, MS_BIND|MS_REC, NULL) < 0) {
+ r = -errno;
+ goto finish;
+ }
+ }
}
- if (n > 0) {
- for (m = mounts; m < mounts + n; ++m) {
+ if (n_mounts > 0) {
+ char **blacklist;
+ unsigned j;
+
+ /* First round, add in all special mounts we need */
+ for (m = mounts; m < mounts + n_mounts; ++m) {
r = apply_mount(m, tmp_dir, var_tmp_dir);
if (r < 0)
- goto fail;
+ goto finish;
}
- for (m = mounts; m < mounts + n; ++m) {
- r = make_read_only(m);
+ /* Create a blacklist we can pass to bind_mount_recursive() */
+ blacklist = newa(char*, n_mounts+1);
+ for (j = 0; j < n_mounts; j++)
+ blacklist[j] = (char*) bind_mount_path(mounts+j);
+ blacklist[j] = NULL;
+
+ /* Second round, flip the ro bits if necessary. */
+ for (m = mounts; m < mounts + n_mounts; ++m) {
+ r = make_read_only(m, blacklist);
if (r < 0)
- goto fail;
+ goto finish;
}
}
if (root_directory) {
/* MS_MOVE does not work on MS_SHARED so the remount MS_SHARED will be done later */
r = mount_move_root(root_directory);
-
- /* at this point, we cannot rollback */
if (r < 0)
- return r;
+ goto finish;
}
/* Remount / as the desired mode. Not that this will not
* reestablish propagation from our side to the host, since
* what's disconnected is disconnected. */
- if (mount(NULL, "/", NULL, mount_flags | MS_REC, NULL) < 0)
- /* at this point, we cannot rollback */
- return -errno;
+ if (mount(NULL, "/", NULL, mount_flags | MS_REC, NULL) < 0) {
+ r = -errno;
+ goto finish;
+ }
- return 0;
+ r = 0;
-fail:
- if (n > 0) {
- for (m = mounts; m < mounts + n; ++m)
- if (m->done)
- (void) umount2(m->path, MNT_DETACH);
- }
+finish:
+ for (m = mounts; m < mounts + n_mounts; m++)
+ free(m->path_malloc);
return r;
}
if (r < 0)
return r;
- x = strjoin(prefix, "/systemd-private-", sd_id128_to_string(boot_id, bid), "-", id, "-XXXXXX", NULL);
+ x = strjoin(prefix, "/systemd-private-", sd_id128_to_string(boot_id, bid), "-", id, "-XXXXXX");
if (!x)
return -ENOMEM;
}
fail:
- lockf(netns_storage_socket[0], F_ULOCK, 0);
+ (void) lockf(netns_storage_socket[0], F_ULOCK, 0);
return r;
}
[PROTECT_SYSTEM_NO] = "no",
[PROTECT_SYSTEM_YES] = "yes",
[PROTECT_SYSTEM_FULL] = "full",
+ [PROTECT_SYSTEM_STRICT] = "strict",
};
DEFINE_STRING_TABLE_LOOKUP(protect_system, ProtectSystem);
projects / thirdparty / systemd.git / blobdiff