/* SPDX-License-Identifier: LGPL-2.1+ */
-/***
- This file is part of systemd.
-
- Copyright 2015 Lennart Poettering
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
#include <sys/mount.h>
#include <linux/magic.h>
#include "alloc-util.h"
#include "escape.h"
#include "fd-util.h"
-#include "fileio.h"
#include "fs-util.h"
#include "label.h"
#include "mkdir.h"
#include "mount-util.h"
+#include "mountpoint-util.h"
#include "nspawn-mount.h"
#include "parse-util.h"
#include "path-util.h"
#include "stat-util.h"
#include "string-util.h"
#include "strv.h"
+#include "tmpfile-util.h"
#include "user-util.h"
#include "util.h"
-CustomMount* custom_mount_add(CustomMount **l, unsigned *n, CustomMountType t) {
+CustomMount* custom_mount_add(CustomMount **l, size_t *n, CustomMountType t) {
CustomMount *c, *ret;
assert(l);
assert(t >= 0);
assert(t < _CUSTOM_MOUNT_TYPE_MAX);
- c = realloc_multiply(*l, (*n + 1), sizeof(CustomMount));
+ c = reallocarray(*l, *n + 1, sizeof(CustomMount));
if (!c)
return NULL;
return ret;
}
-void custom_mount_free_all(CustomMount *l, unsigned n) {
- unsigned i;
+void custom_mount_free_all(CustomMount *l, size_t n) {
+ size_t i;
for (i = 0; i < n; i++) {
CustomMount *m = l + i;
free(l);
}
-static int custom_mount_compare(const void *a, const void *b) {
- const CustomMount *x = a, *y = b;
+static int custom_mount_compare(const CustomMount *a, const CustomMount *b) {
int r;
- r = path_compare(x->destination, y->destination);
+ r = path_compare(a->destination, b->destination);
if (r != 0)
return r;
- if (x->type < y->type)
- return -1;
- if (x->type > y->type)
- return 1;
-
- return 0;
+ return CMP(a->type, b->type);
}
static bool source_path_is_valid(const char *p) {
return strdup(source);
}
-int custom_mount_prepare_all(const char *dest, CustomMount *l, unsigned n) {
- unsigned i;
+int custom_mount_prepare_all(const char *dest, CustomMount *l, size_t n) {
+ size_t i;
int r;
/* Prepare all custom mounts. This will make source we know all temporary directories. This is called in the
assert(l || n == 0);
/* Order the custom mounts, and make sure we have a working directory */
- qsort_safe(l, n, sizeof(CustomMount), custom_mount_compare);
+ typesafe_qsort(l, n, custom_mount_compare);
for (i = 0; i < n; i++) {
CustomMount *m = l + i;
if (!s)
return log_oom();
- free(m->source);
- m->source = s;
+ free_and_replace(m->source, s);
} else {
/* No source specified? In that case, use a throw-away temporary directory in /var/tmp */
if (!s)
return log_oom();
- free(*j);
- *j = s;
+ free_and_replace(*j, s);
}
if (m->work_dir) {
if (!s)
return log_oom();
- free(m->work_dir);
- m->work_dir = s;
+ free_and_replace(m->work_dir, s);
} else {
assert(m->source);
return 0;
}
-int bind_mount_parse(CustomMount **l, unsigned *n, const char *s, bool read_only) {
+int bind_mount_parse(CustomMount **l, size_t *n, const char *s, bool read_only) {
_cleanup_free_ char *source = NULL, *destination = NULL, *opts = NULL;
const char *p = s;
CustomMount *m;
return 0;
}
-int tmpfs_mount_parse(CustomMount **l, unsigned *n, const char *s) {
+int tmpfs_mount_parse(CustomMount **l, size_t *n, const char *s) {
_cleanup_free_ char *path = NULL, *opts = NULL;
const char *p = s;
CustomMount *m;
if (!m)
return -ENOMEM;
- m->destination = path;
- m->options = opts;
+ m->destination = TAKE_PTR(path);
+ m->options = TAKE_PTR(opts);
- path = opts = NULL;
return 0;
}
-int overlay_mount_parse(CustomMount **l, unsigned *n, const char *s, bool read_only) {
+int overlay_mount_parse(CustomMount **l, size_t *n, const char *s, bool read_only) {
_cleanup_free_ char *upper = NULL, *destination = NULL;
_cleanup_strv_free_ char **lower = NULL;
CustomMount *m;
!source_path_is_valid(lower[1]))
return -EINVAL;
- upper = lower[1];
- lower[1] = NULL;
+ upper = TAKE_PTR(lower[1]);
destination = strdup(upper[0] == '+' ? upper+1 : upper); /* take the destination without "+" prefix */
if (!destination)
* the "upper", and all before that the "lower" directories. */
destination = lower[k - 1];
- upper = lower[k - 2];
- lower[k - 2] = NULL;
+ upper = TAKE_PTR(lower[k - 2]);
STRV_FOREACH(i, lower)
if (!source_path_is_valid(*i))
if (!m)
return -ENOMEM;
- m->destination = destination;
- m->source = upper;
- m->lower = lower;
+ m->destination = TAKE_PTR(destination);
+ m->source = TAKE_PTR(upper);
+ m->lower = TAKE_PTR(lower);
m->read_only = read_only;
- upper = destination = NULL;
- lower = NULL;
-
return 0;
}
-static int tmpfs_patch_options(
+int tmpfs_patch_options(
const char *options,
- bool userns,
- uid_t uid_shift, uid_t uid_range,
- bool patch_ids,
+ uid_t uid_shift,
const char *selinux_apifs_context,
char **ret) {
char *buf = NULL;
- if ((userns && uid_shift != 0) || patch_ids) {
- assert(uid_shift != UID_INVALID);
-
+ if (uid_shift != UID_INVALID) {
if (asprintf(&buf, "%s%suid=" UID_FMT ",gid=" UID_FMT,
strempty(options), options ? "," : "",
uid_shift, uid_shift) < 0)
/* Create mountpoint for cgroups. Otherwise we are not allowed since we
* remount /sys read-only.
*/
- if (cg_ns_supported()) {
- x = prefix_roota(top, "/fs/cgroup");
- (void) mkdir_p(x, 0755);
- }
+ x = prefix_roota(top, "/fs/cgroup");
+ (void) mkdir_p(x, 0755);
return mount_verbose(LOG_ERR, NULL, top, NULL,
MS_BIND|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT|extra_flags, NULL);
}
-static int mkdir_userns(const char *path, mode_t mode, MountSettingsMask mask, uid_t uid_shift) {
+static int mkdir_userns(const char *path, mode_t mode, uid_t uid_shift) {
int r;
assert(path);
if (r < 0 && r != -EEXIST)
return r;
- if ((mask & MOUNT_USE_USERNS) == 0)
- return 0;
-
- if (mask & MOUNT_IN_USERNS)
+ if (uid_shift == UID_INVALID)
return 0;
if (lchown(path, uid_shift, uid_shift) < 0)
return 0;
}
-static int mkdir_userns_p(const char *prefix, const char *path, mode_t mode, MountSettingsMask mask, uid_t uid_shift) {
+static int mkdir_userns_p(const char *prefix, const char *path, mode_t mode, uid_t uid_shift) {
const char *p, *e;
int r;
if (prefix && path_startswith(prefix, t))
continue;
- r = mkdir_userns(t, mode, mask, uid_shift);
+ r = mkdir_userns(t, mode, uid_shift);
if (r < 0)
return r;
}
- return mkdir_userns(path, mode, mask, uid_shift);
+ return mkdir_userns(path, mode, uid_shift);
}
int mount_all(const char *dest,
MountSettingsMask mount_settings,
- uid_t uid_shift, uid_t uid_range,
+ uid_t uid_shift,
const char *selinux_apifs_context) {
+#define PROC_INACCESSIBLE(path) \
+ { NULL, (path), NULL, NULL, MS_BIND, \
+ MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO|MOUNT_INACCESSIBLE_REG }, /* Bind mount first ... */ \
+ { NULL, (path), NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, \
+ MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO } /* Then, make it r/o */
+
+#define PROC_READ_ONLY(path) \
+ { (path), (path), NULL, NULL, MS_BIND, \
+ MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* Bind mount first ... */ \
+ { NULL, (path), NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, \
+ MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO } /* Then, make it r/o */
+
typedef struct MountPoint {
const char *what;
const char *where;
} MountPoint;
static const MountPoint mount_table[] = {
- /* inner child mounts */
- { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, MOUNT_FATAL|MOUNT_IN_USERNS },
- { "/proc/sys", "/proc/sys", NULL, NULL, MS_BIND, MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* Bind mount first ... */
- { "/proc/sys/net", "/proc/sys/net", NULL, NULL, MS_BIND, MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO|MOUNT_APPLY_APIVFS_NETNS }, /* (except for this) */
- { NULL, "/proc/sys", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* ... then, make it r/o */
- { "/proc/sysrq-trigger", "/proc/sysrq-trigger", NULL, NULL, MS_BIND, MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* Bind mount first ... */
- { NULL, "/proc/sysrq-trigger", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* ... then, make it r/o */
-
- /* outer child mounts */
- { "tmpfs", "/tmp", "tmpfs", "mode=1777", MS_NOSUID|MS_NODEV|MS_STRICTATIME, MOUNT_FATAL },
- { "tmpfs", "/sys", "tmpfs", "mode=755", MS_NOSUID|MS_NOEXEC|MS_NODEV, MOUNT_FATAL|MOUNT_APPLY_APIVFS_NETNS },
- { "sysfs", "/sys", "sysfs", NULL, MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, MOUNT_FATAL|MOUNT_APPLY_APIVFS_RO }, /* skipped if above was mounted */
- { "sysfs", "/sys", "sysfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, MOUNT_FATAL }, /* skipped if above was mounted */
-
- { "tmpfs", "/dev", "tmpfs", "mode=755", MS_NOSUID|MS_STRICTATIME, MOUNT_FATAL },
- { "tmpfs", "/dev/shm", "tmpfs", "mode=1777", MS_NOSUID|MS_NODEV|MS_STRICTATIME, MOUNT_FATAL },
- { "tmpfs", "/run", "tmpfs", "mode=755", MS_NOSUID|MS_NODEV|MS_STRICTATIME, MOUNT_FATAL },
+ /* First we list inner child mounts (i.e. mounts applied *after* entering user namespacing) */
+ { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV,
+ MOUNT_FATAL|MOUNT_IN_USERNS },
+
+ { "/proc/sys", "/proc/sys", NULL, NULL, MS_BIND,
+ MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* Bind mount first ... */
+
+ { "/proc/sys/net", "/proc/sys/net", NULL, NULL, MS_BIND,
+ MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO|MOUNT_APPLY_APIVFS_NETNS }, /* (except for this) */
+
+ { NULL, "/proc/sys", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT,
+ MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* ... then, make it r/o */
+
+ /* Make these files inaccessible to container payloads: they potentially leak information about kernel
+ * internals or the host's execution environment to the container */
+ PROC_INACCESSIBLE("/proc/kallsyms"),
+ PROC_INACCESSIBLE("/proc/kcore"),
+ PROC_INACCESSIBLE("/proc/keys"),
+ PROC_INACCESSIBLE("/proc/sysrq-trigger"),
+ PROC_INACCESSIBLE("/proc/timer_list"),
+
+ /* Make these directories read-only to container payloads: they show hardware information, and in some
+ * cases contain tunables the container really shouldn't have access to. */
+ PROC_READ_ONLY("/proc/acpi"),
+ PROC_READ_ONLY("/proc/apm"),
+ PROC_READ_ONLY("/proc/asound"),
+ PROC_READ_ONLY("/proc/bus"),
+ PROC_READ_ONLY("/proc/fs"),
+ PROC_READ_ONLY("/proc/irq"),
+ PROC_READ_ONLY("/proc/scsi"),
+
+ /* Then we list outer child mounts (i.e. mounts applied *before* entering user namespacing) */
+ { "tmpfs", "/tmp", "tmpfs", "mode=1777", MS_NOSUID|MS_NODEV|MS_STRICTATIME,
+ MOUNT_FATAL|MOUNT_APPLY_TMPFS_TMP },
+ { "tmpfs", "/sys", "tmpfs", "mode=555", MS_NOSUID|MS_NOEXEC|MS_NODEV,
+ MOUNT_FATAL|MOUNT_APPLY_APIVFS_NETNS },
+ { "sysfs", "/sys", "sysfs", NULL, MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV,
+ MOUNT_FATAL|MOUNT_APPLY_APIVFS_RO }, /* skipped if above was mounted */
+ { "sysfs", "/sys", "sysfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV,
+ MOUNT_FATAL }, /* skipped if above was mounted */
+ { "tmpfs", "/dev", "tmpfs", "mode=755", MS_NOSUID|MS_STRICTATIME,
+ MOUNT_FATAL },
+ { "tmpfs", "/dev/shm", "tmpfs", "mode=1777", MS_NOSUID|MS_NODEV|MS_STRICTATIME,
+ MOUNT_FATAL },
+ { "tmpfs", "/run", "tmpfs", "mode=755", MS_NOSUID|MS_NODEV|MS_STRICTATIME,
+ MOUNT_FATAL },
+ { "mqueue", "/dev/mqueue", "mqueue", NULL, 0,
+ MOUNT_FATAL },
+
#if HAVE_SELINUX
- { "/sys/fs/selinux", "/sys/fs/selinux", NULL, NULL, MS_BIND, 0 }, /* Bind mount first */
- { NULL, "/sys/fs/selinux", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, 0 }, /* Then, make it r/o */
+ { "/sys/fs/selinux", "/sys/fs/selinux", NULL, NULL, MS_BIND,
+ 0 }, /* Bind mount first */
+ { NULL, "/sys/fs/selinux", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT,
+ 0 }, /* Then, make it r/o */
#endif
};
- unsigned k;
- int r;
+ _cleanup_(unlink_and_freep) char *inaccessible = NULL;
bool use_userns = (mount_settings & MOUNT_USE_USERNS);
bool netns = (mount_settings & MOUNT_APPLY_APIVFS_NETNS);
bool ro = (mount_settings & MOUNT_APPLY_APIVFS_RO);
bool in_userns = (mount_settings & MOUNT_IN_USERNS);
+ bool tmpfs_tmp = (mount_settings & MOUNT_APPLY_TMPFS_TMP);
+ size_t k;
+ int r;
for (k = 0; k < ELEMENTSOF(mount_table); k++) {
_cleanup_free_ char *where = NULL, *options = NULL;
- const char *o;
+ const char *o, *what;
bool fatal = (mount_table[k].mount_settings & MOUNT_FATAL);
if (in_userns != (bool)(mount_table[k].mount_settings & MOUNT_IN_USERNS))
if (!ro && (bool)(mount_table[k].mount_settings & MOUNT_APPLY_APIVFS_RO))
continue;
+ if (!tmpfs_tmp && (bool)(mount_table[k].mount_settings & MOUNT_APPLY_TMPFS_TMP))
+ continue;
+
r = chase_symlinks(mount_table[k].where, dest, CHASE_NONEXISTENT|CHASE_PREFIX_ROOT, &where);
if (r < 0)
return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, mount_table[k].where);
+ if (mount_table[k].mount_settings & MOUNT_INACCESSIBLE_REG) {
+
+ if (!inaccessible) {
+ _cleanup_free_ char *np = NULL;
+
+ r = tempfn_random_child(NULL, "inaccessible", &np);
+ if (r < 0)
+ return log_error_errno(r, "Failed to generate inaccessible file node path: %m");
+
+ r = touch_file(np, false, USEC_INFINITY, UID_INVALID, GID_INVALID, 0000);
+ if (r < 0)
+ return log_error_errno(r, "Failed to create inaccessible file node '%s': %m", np);
+
+ inaccessible = TAKE_PTR(np);
+ }
+
+ what = inaccessible;
+ } else
+ what = mount_table[k].what;
+
r = path_is_mount_point(where, NULL, 0);
if (r < 0 && r != -ENOENT)
return log_error_errno(r, "Failed to detect whether %s is a mount point: %m", where);
/* Skip this entry if it is not a remount. */
- if (mount_table[k].what && r > 0)
+ if (what && r > 0)
continue;
- r = mkdir_userns_p(dest, where, 0755, mount_settings, uid_shift);
+ r = mkdir_userns_p(dest, where, 0755, (use_userns && !in_userns) ? uid_shift : UID_INVALID);
if (r < 0 && r != -EEXIST) {
if (fatal && r != -EROFS)
return log_error_errno(r, "Failed to create directory %s: %m", where);
o = mount_table[k].options;
if (streq_ptr(mount_table[k].type, "tmpfs")) {
- if (in_userns)
- r = tmpfs_patch_options(o, use_userns, 0, uid_range, true, selinux_apifs_context, &options);
- else
- r = tmpfs_patch_options(o, use_userns, uid_shift, uid_range, false, selinux_apifs_context, &options);
+ r = tmpfs_patch_options(o, in_userns ? 0 : uid_shift, selinux_apifs_context, &options);
if (r < 0)
return log_oom();
if (r > 0)
}
r = mount_verbose(fatal ? LOG_ERR : LOG_DEBUG,
- mount_table[k].what,
+ what,
where,
mount_table[k].type,
mount_table[k].flags,
if (stat(where, &dest_st) < 0)
return log_error_errno(errno, "Failed to stat %s: %m", where);
- if (S_ISDIR(source_st.st_mode) && !S_ISDIR(dest_st.st_mode)) {
- log_error("Cannot bind mount directory %s on file %s.", m->source, where);
- return -EINVAL;
- }
+ if (S_ISDIR(source_st.st_mode) && !S_ISDIR(dest_st.st_mode))
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+ "Cannot bind mount directory %s on file %s.",
+ m->source, where);
- if (!S_ISDIR(source_st.st_mode) && S_ISDIR(dest_st.st_mode)) {
- log_error("Cannot bind mount file %s on directory %s.", m->source, where);
- return -EINVAL;
- }
+ if (!S_ISDIR(source_st.st_mode) && S_ISDIR(dest_st.st_mode))
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+ "Cannot bind mount file %s on directory %s.",
+ m->source, where);
} else { /* Path doesn't exist yet? */
r = mkdir_parents_label(where, 0755);
return log_error_errno(r, "Creating mount point for tmpfs %s failed: %m", where);
}
- r = tmpfs_patch_options(m->options, userns, uid_shift, uid_range, false, selinux_apifs_context, &buf);
+ r = tmpfs_patch_options(m->options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf);
if (r < 0)
return log_oom();
options = r > 0 ? buf : m->options;
int mount_custom(
const char *dest,
- CustomMount *mounts, unsigned n,
+ CustomMount *mounts, size_t n,
bool userns, uid_t uid_shift, uid_t uid_range,
const char *selinux_apifs_context) {
- unsigned i;
+ size_t i;
int r;
assert(dest);
return 0;
}
-/* Retrieve existing subsystems. This function is called in a new cgroup
- * namespace.
- */
-static int get_process_controllers(Set **ret) {
- _cleanup_set_free_free_ Set *controllers = NULL;
- _cleanup_fclose_ FILE *f = NULL;
- int r;
-
- assert(ret);
-
- controllers = set_new(&string_hash_ops);
- if (!controllers)
- return -ENOMEM;
-
- f = fopen("/proc/self/cgroup", "re");
- if (!f)
- return errno == ENOENT ? -ESRCH : -errno;
-
- for (;;) {
- _cleanup_free_ char *line = NULL;
- char *e, *l;
-
- r = read_line(f, LONG_LINE_MAX, &line);
- if (r < 0)
- return r;
- if (r == 0)
- break;
-
- l = strchr(line, ':');
- if (!l)
- continue;
-
- l++;
- e = strchr(l, ':');
- if (!e)
- continue;
-
- *e = 0;
-
- if (STR_IN_SET(l, "", "name=systemd", "name=unified"))
- continue;
-
- r = set_put_strdup(controllers, l);
- if (r < 0)
- return r;
- }
-
- *ret = controllers;
- controllers = NULL;
-
- return 0;
-}
-
-static int mount_legacy_cgroup_hierarchy(
- const char *dest,
- const char *controller,
- const char *hierarchy,
- bool read_only) {
-
- const char *to, *fstype, *opts;
- int r;
-
- to = strjoina(strempty(dest), "/sys/fs/cgroup/", hierarchy);
-
- r = path_is_mount_point(to, dest, 0);
- if (r < 0 && r != -ENOENT)
- return log_error_errno(r, "Failed to determine if %s is mounted already: %m", to);
- if (r > 0)
- return 0;
-
- mkdir_p(to, 0755);
-
- /* The superblock mount options of the mount point need to be
- * identical to the hosts', and hence writable... */
- if (streq(controller, SYSTEMD_CGROUP_CONTROLLER_HYBRID)) {
- fstype = "cgroup2";
- opts = NULL;
- } else if (streq(controller, SYSTEMD_CGROUP_CONTROLLER_LEGACY)) {
- fstype = "cgroup";
- opts = "none,name=systemd,xattr";
- } else {
- fstype = "cgroup";
- opts = controller;
- }
-
- r = mount_verbose(LOG_ERR, "cgroup", to, fstype, MS_NOSUID|MS_NOEXEC|MS_NODEV, opts);
- if (r < 0)
- return r;
-
- /* ... hence let's only make the bind mount read-only, not the superblock. */
- if (read_only) {
- r = mount_verbose(LOG_ERR, NULL, to, NULL,
- MS_BIND|MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, NULL);
- if (r < 0)
- return r;
- }
-
- return 1;
-}
-
-/* Mount a legacy cgroup hierarchy when cgroup namespaces are supported. */
-static int mount_legacy_cgns_supported(
- const char *dest,
- CGroupUnified unified_requested,
- bool userns,
- uid_t uid_shift,
- uid_t uid_range,
- const char *selinux_apifs_context) {
-
- _cleanup_set_free_free_ Set *controllers = NULL;
- const char *cgroup_root = "/sys/fs/cgroup", *c;
- int r;
-
- (void) mkdir_p(cgroup_root, 0755);
-
- /* Mount a tmpfs to /sys/fs/cgroup if it's not mounted there yet. */
- r = path_is_mount_point(cgroup_root, dest, AT_SYMLINK_FOLLOW);
- if (r < 0)
- return log_error_errno(r, "Failed to determine if /sys/fs/cgroup is already mounted: %m");
- if (r == 0) {
- _cleanup_free_ char *options = NULL;
-
- /* When cgroup namespaces are enabled and user namespaces are
- * used then the mount of the cgroupfs is done *inside* the new
- * user namespace. We're root in the new user namespace and the
- * kernel will happily translate our uid/gid to the correct
- * uid/gid as seen from e.g. /proc/1/mountinfo. So we simply
- * pass uid 0 and not uid_shift to tmpfs_patch_options().
- */
- r = tmpfs_patch_options("mode=755", userns, 0, uid_range, true, selinux_apifs_context, &options);
- if (r < 0)
- return log_oom();
-
- r = mount_verbose(LOG_ERR, "tmpfs", cgroup_root, "tmpfs",
- MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME, options);
- if (r < 0)
- return r;
- }
-
- r = cg_all_unified();
- if (r < 0)
- return r;
- if (r > 0)
- goto skip_controllers;
-
- r = get_process_controllers(&controllers);
- if (r < 0)
- return log_error_errno(r, "Failed to determine cgroup controllers: %m");
-
- for (;;) {
- _cleanup_free_ const char *controller = NULL;
-
- controller = set_steal_first(controllers);
- if (!controller)
- break;
-
- r = mount_legacy_cgroup_hierarchy("", controller, controller, !userns);
- if (r < 0)
- return r;
-
- /* When multiple hierarchies are co-mounted, make their
- * constituting individual hierarchies a symlink to the
- * co-mount.
- */
- c = controller;
- for (;;) {
- _cleanup_free_ char *target = NULL, *tok = NULL;
-
- r = extract_first_word(&c, &tok, ",", 0);
- if (r < 0)
- return log_error_errno(r, "Failed to extract co-mounted cgroup controller: %m");
- if (r == 0)
- break;
-
- if (streq(controller, tok))
- break;
-
- target = prefix_root("/sys/fs/cgroup/", tok);
- if (!target)
- return log_oom();
-
- r = symlink_idempotent(controller, target);
- if (r == -EINVAL)
- return log_error_errno(r, "Invalid existing symlink for combined hierarchy: %m");
- if (r < 0)
- return log_error_errno(r, "Failed to create symlink for combined hierarchy: %m");
- }
- }
-
-skip_controllers:
- if (unified_requested >= CGROUP_UNIFIED_SYSTEMD) {
- r = mount_legacy_cgroup_hierarchy("", SYSTEMD_CGROUP_CONTROLLER_HYBRID, "unified", false);
- if (r < 0)
- return r;
- }
-
- r = mount_legacy_cgroup_hierarchy("", SYSTEMD_CGROUP_CONTROLLER_LEGACY, "systemd", false);
- if (r < 0)
- return r;
-
- if (!userns)
- return mount_verbose(LOG_ERR, NULL, cgroup_root, NULL,
- MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME|MS_RDONLY, "mode=755");
-
- return 0;
-}
-
-/* Mount legacy cgroup hierarchy when cgroup namespaces are unsupported. */
-static int mount_legacy_cgns_unsupported(
- const char *dest,
- CGroupUnified unified_requested,
- bool userns,
- uid_t uid_shift,
- uid_t uid_range,
- const char *selinux_apifs_context) {
-
- _cleanup_set_free_free_ Set *controllers = NULL;
- const char *cgroup_root;
- int r;
-
- cgroup_root = prefix_roota(dest, "/sys/fs/cgroup");
-
- (void) mkdir_p(cgroup_root, 0755);
-
- /* Mount a tmpfs to /sys/fs/cgroup if it's not mounted there yet. */
- r = path_is_mount_point(cgroup_root, dest, AT_SYMLINK_FOLLOW);
- if (r < 0)
- return log_error_errno(r, "Failed to determine if /sys/fs/cgroup is already mounted: %m");
- if (r == 0) {
- _cleanup_free_ char *options = NULL;
-
- r = tmpfs_patch_options("mode=755", userns, uid_shift, uid_range, false, selinux_apifs_context, &options);
- if (r < 0)
- return log_oom();
-
- r = mount_verbose(LOG_ERR, "tmpfs", cgroup_root, "tmpfs",
- MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME, options);
- if (r < 0)
- return r;
- }
-
- r = cg_all_unified();
- if (r < 0)
- return r;
- if (r > 0)
- goto skip_controllers;
-
- r = cg_kernel_controllers(&controllers);
- if (r < 0)
- return log_error_errno(r, "Failed to determine cgroup controllers: %m");
-
- for (;;) {
- _cleanup_free_ char *controller = NULL, *origin = NULL, *combined = NULL;
-
- controller = set_steal_first(controllers);
- if (!controller)
- break;
-
- origin = prefix_root("/sys/fs/cgroup/", controller);
- if (!origin)
- return log_oom();
-
- r = readlink_malloc(origin, &combined);
- if (r == -EINVAL) {
- /* Not a symbolic link, but directly a single cgroup hierarchy */
-
- r = mount_legacy_cgroup_hierarchy(dest, controller, controller, true);
- if (r < 0)
- return r;
-
- } else if (r < 0)
- return log_error_errno(r, "Failed to read link %s: %m", origin);
- else {
- _cleanup_free_ char *target = NULL;
-
- target = prefix_root(dest, origin);
- if (!target)
- return log_oom();
-
- /* A symbolic link, a combination of controllers in one hierarchy */
-
- if (!filename_is_valid(combined)) {
- log_warning("Ignoring invalid combined hierarchy %s.", combined);
- continue;
- }
-
- r = mount_legacy_cgroup_hierarchy(dest, combined, combined, true);
- if (r < 0)
- return r;
-
- r = symlink_idempotent(combined, target);
- if (r == -EINVAL)
- return log_error_errno(r, "Invalid existing symlink for combined hierarchy: %m");
- if (r < 0)
- return log_error_errno(r, "Failed to create symlink for combined hierarchy: %m");
- }
- }
-
-skip_controllers:
- if (unified_requested >= CGROUP_UNIFIED_SYSTEMD) {
- r = mount_legacy_cgroup_hierarchy(dest, SYSTEMD_CGROUP_CONTROLLER_HYBRID, "unified", false);
- if (r < 0)
- return r;
- }
-
- r = mount_legacy_cgroup_hierarchy(dest, SYSTEMD_CGROUP_CONTROLLER_LEGACY, "systemd", false);
- if (r < 0)
- return r;
-
- return mount_verbose(LOG_ERR, NULL, cgroup_root, NULL,
- MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME|MS_RDONLY, "mode=755");
-}
-
-static int mount_unified_cgroups(const char *dest) {
- const char *p;
- int r;
-
- assert(dest);
-
- p = prefix_roota(dest, "/sys/fs/cgroup");
-
- (void) mkdir_p(p, 0755);
-
- r = path_is_mount_point(p, dest, AT_SYMLINK_FOLLOW);
- if (r < 0)
- return log_error_errno(r, "Failed to determine if %s is mounted already: %m", p);
- if (r > 0) {
- p = prefix_roota(dest, "/sys/fs/cgroup/cgroup.procs");
- if (access(p, F_OK) >= 0)
- return 0;
- if (errno != ENOENT)
- return log_error_errno(errno, "Failed to determine if mount point %s contains the unified cgroup hierarchy: %m", p);
-
- log_error("%s is already mounted but not a unified cgroup hierarchy. Refusing.", p);
- return -EINVAL;
- }
-
- return mount_verbose(LOG_ERR, "cgroup", p, "cgroup2", MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL);
-}
-
-int mount_cgroups(
- const char *dest,
- CGroupUnified unified_requested,
- bool userns,
- uid_t uid_shift,
- uid_t uid_range,
- const char *selinux_apifs_context,
- bool use_cgns) {
-
- if (unified_requested >= CGROUP_UNIFIED_ALL)
- return mount_unified_cgroups(dest);
- if (use_cgns)
- return mount_legacy_cgns_supported(dest, unified_requested, userns, uid_shift, uid_range, selinux_apifs_context);
-
- return mount_legacy_cgns_unsupported(dest, unified_requested, userns, uid_shift, uid_range, selinux_apifs_context);
-}
-
-static int mount_systemd_cgroup_writable_one(const char *root, const char *own) {
- int r;
-
- assert(root);
- assert(own);
-
- /* Make our own cgroup a (writable) bind mount */
- r = mount_verbose(LOG_ERR, own, own, NULL, MS_BIND, NULL);
- if (r < 0)
- return r;
-
- /* And then remount the systemd cgroup root read-only */
- return mount_verbose(LOG_ERR, NULL, root, NULL,
- MS_BIND|MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, NULL);
-}
-
-int mount_systemd_cgroup_writable(
- const char *dest,
- CGroupUnified unified_requested) {
-
- _cleanup_free_ char *own_cgroup_path = NULL;
- const char *root, *own;
- int r;
-
- assert(dest);
-
- r = cg_pid_get_path(NULL, 0, &own_cgroup_path);
- if (r < 0)
- return log_error_errno(r, "Failed to determine our own cgroup path: %m");
-
- /* If we are living in the top-level, then there's nothing to do... */
- if (path_equal(own_cgroup_path, "/"))
- return 0;
-
- if (unified_requested >= CGROUP_UNIFIED_ALL) {
-
- root = prefix_roota(dest, "/sys/fs/cgroup");
- own = strjoina(root, own_cgroup_path);
-
- } else {
-
- if (unified_requested >= CGROUP_UNIFIED_SYSTEMD) {
- root = prefix_roota(dest, "/sys/fs/cgroup/unified");
- own = strjoina(root, own_cgroup_path);
-
- r = mount_systemd_cgroup_writable_one(root, own);
- if (r < 0)
- return r;
- }
-
- root = prefix_roota(dest, "/sys/fs/cgroup/systemd");
- own = strjoina(root, own_cgroup_path);
- }
-
- return mount_systemd_cgroup_writable_one(root, own);
-}
-
int setup_volatile_state(
const char *directory,
VolatileMode mode,
return log_error_errno(errno, "Failed to create %s: %m", directory);
options = "mode=755";
- r = tmpfs_patch_options(options, userns, uid_shift, uid_range, false, selinux_apifs_context, &buf);
+ r = tmpfs_patch_options(options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf);
if (r < 0)
return log_oom();
if (r > 0)
return log_error_errno(errno, "Failed to create temporary directory: %m");
options = "mode=755";
- r = tmpfs_patch_options(options, userns, uid_shift, uid_range, false, selinux_apifs_context, &buf);
+ r = tmpfs_patch_options(options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf);
if (r < 0)
return log_oom();
if (r > 0)
projects / thirdparty / systemd.git / blobdiff