20977275812

Committed 13 Jan 2026 03:18AM UTC coverage: 72.685% (+0.3%) from 72.39%

Build # 20977275812

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push

github

Committed by

web-flow

Commit Message

Bump kernel requirements to >= 5.10, and recommend >= 5.14 (#38977)

Then, this drops several unnecessary code for older kernels.

Run Details

83 of 98 new or added lines in 14 files covered. (84.69%)

267 existing lines in 44 files now uncovered.

310058 of 426578 relevant lines covered (72.68%)

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Source File
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53.53

/src/shared/mount-setup.c

/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include <sys/mount.h>
#include <unistd.h>

#include "alloc-util.h"
#include "conf-files.h"
#include "dev-setup.h"
#include "efivars.h"
#include "errno-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "label-util.h"
#include "log.h"
#include "mkdir-label.h"
#include "mount-setup.h"
#include "mount-util.h"
#include "mountpoint-util.h"
#include "path-util.h"
#include "recurse-dir.h"
#include "smack-util.h"
#include "string-util.h"
#include "strv.h"
#include "time-util.h"
#include "virt.h"

typedef enum MountMode {
        MNT_FATAL             = 1 << 0,
        MNT_IN_CONTAINER      = 1 << 1,
        MNT_CHECK_WRITABLE    = 1 << 2,
        MNT_FOLLOW_SYMLINK    = 1 << 3,
} MountMode;

typedef struct MountPoint {
        const char *what;
        const char *where;
        const char *type;
        const char *options;
        int (*options_fn)(int priority, const char *type, char **ret);
        unsigned long flags;
        MountMode mode;
        bool (*condition_fn)(void);
} MountPoint;

static int cgroupfs_mount_options(int priority, const char *type, char **ret) {
        int r;

        assert(type);
        assert(streq(type, "cgroup2"));
        assert(ret);

        /* memory_hugetlb_accounting mount option is since kernel v6.7 (8cba9576df601c384abd334a503c3f6e1e29eefb). */

        r = mount_option_supported("cgroup2", "memory_hugetlb_accounting", /* value= */ NULL);
        if (r <= 0) {
                if (r < 0)
                        log_full_errno(priority, r, "Failed to determine whether cgroupfs supports 'memory_hugetlb_accounting' mount option, assuming not: %m");
                else
                        log_debug("'memory_hugetlb_accounting' not supported by cgroupfs, not using mount option.");

                *ret = NULL;
                return 0;
        }

        return strdup_to(ret, "memory_hugetlb_accounting");
}

int mount_cgroupfs(const char *path) {
        int r;

        assert(path);

        /* Mount a separate cgroupfs instance, taking all options we initial set into account. This is
         * especially useful when cgroup namespace is *not* employed, since the kernel overrides all
         * previous options if a new mount is established in initial cgns (c.f.
         * https://github.com/torvalds/linux/blob/b69bb476dee99d564d65d418e9a20acca6f32c3f/kernel/cgroup/cgroup.c#L1984)
         */

        _cleanup_free_ char *opts = NULL;
        r = cgroupfs_mount_options(LOG_WARNING, "cgroup2", &opts);
        if (r < 0)
                return r;

        /* These options shall be kept in sync with those in mount_table below. */
        if (!strprepend_with_separator(&opts, ",", "nsdelegate,memory_recursiveprot"))
                return log_oom();

        return mount_nofollow_verbose(LOG_ERR, "cgroup2", path, "cgroup2", MS_NOSUID|MS_NOEXEC|MS_NODEV, opts);
}

static int usrquota_mount_option(int priority, const char *type, char **ret) {
        _cleanup_free_ char *o = NULL;
        int r;

        assert(type);
        assert(ret);

        r = mount_option_supported(type, "usrquota", /* value= */ NULL);
        if (r < 0)
                log_full_errno(priority, r, "Unable to determine whether %s supports 'usrquota' mount option, assuming not: %m", type);
        else if (r == 0)
                log_debug("Not enabling 'usrquota' for '%s' as kernel lacks support for it.", type);
        else {
                o = strdup("usrquota");
                if (!o)
                        return log_oom_full(priority);
        }

        *ret = TAKE_PTR(o);
        return 0;
}

static const MountPoint mount_table[] = {
        {
                .what = "proc",
                .where = "/proc",
                .type = "proc",
                .flags = MS_NOSUID|MS_NOEXEC|MS_NODEV,
                .mode = MNT_FATAL|MNT_IN_CONTAINER|MNT_FOLLOW_SYMLINK,
        },
        {
                .what = "sysfs",
                .where = "/sys",
                .type = "sysfs",
                .flags = MS_NOSUID|MS_NOEXEC|MS_NODEV,
                .mode = MNT_FATAL|MNT_IN_CONTAINER,
        },
        {
                .what = "devtmpfs",
                .where = "/dev",
                .type = "devtmpfs",
                .options = "mode=0755" TMPFS_LIMITS_DEV,
                .flags = MS_NOSUID|MS_STRICTATIME,
                .mode = MNT_FATAL|MNT_IN_CONTAINER,
        },
        {
                .what = "securityfs",
                .where = "/sys/kernel/security",
                .type = "securityfs",
                .flags = MS_NOSUID|MS_NOEXEC|MS_NODEV,
        },
#if ENABLE_SMACK
        {
                .what = "smackfs",
                .where = "/sys/fs/smackfs",
                .type = "smackfs",
                .options = "smackfsdef=*",
                .flags = MS_NOSUID|MS_NOEXEC|MS_NODEV,
                .mode = MNT_FATAL,
                .condition_fn = mac_smack_use,
        },
        {
                .what = "tmpfs",
                .where = "/dev/shm",
                .type = "tmpfs",
                .options = "mode=01777,smackfsroot=*",
                .options_fn = usrquota_mount_option,
                .flags = MS_NOSUID|MS_NODEV|MS_STRICTATIME,
                .mode = MNT_FATAL,
                .condition_fn = mac_smack_use,
        },
#endif
        {
                .what = "tmpfs",
                .where = "/dev/shm",
                .type = "tmpfs",
                .options = "mode=01777",
                .options_fn = usrquota_mount_option,
                .flags = MS_NOSUID|MS_NODEV|MS_STRICTATIME,
                .mode = MNT_FATAL|MNT_IN_CONTAINER,
        },
        {
                .what = "devpts",
                .where = "/dev/pts",
                .type = "devpts",
                .options = "mode=" STRINGIFY(TTY_MODE) ",gid=" STRINGIFY(TTY_GID),
                .flags = MS_NOSUID|MS_NOEXEC,
                .mode = MNT_IN_CONTAINER,
        },
#if ENABLE_SMACK
        {
                .what = "tmpfs",
                .where = "/run",
                .type = "tmpfs",
                .options = "mode=0755,smackfsroot=*" TMPFS_LIMITS_RUN,
                .flags = MS_NOSUID|MS_NODEV|MS_STRICTATIME,
                .mode = MNT_FATAL,
                .condition_fn = mac_smack_use,
        },
#endif
        {
                .what = "tmpfs",
                .where = "/run",
                .type = "tmpfs",
                .options = "mode=0755" TMPFS_LIMITS_RUN,
                .flags = MS_NOSUID|MS_NODEV|MS_STRICTATIME,
                .mode = MNT_FATAL|MNT_IN_CONTAINER,
        },
        {
                .what = "cgroup2",
                .where = "/sys/fs/cgroup",
                .type = "cgroup2",
                .options = "nsdelegate,memory_recursiveprot",
                .options_fn = cgroupfs_mount_options,
                .flags = MS_NOSUID|MS_NOEXEC|MS_NODEV,
                .mode = MNT_FATAL|MNT_IN_CONTAINER|MNT_CHECK_WRITABLE,
        },
#if ENABLE_PSTORE
        {
                .what = "pstore",
                .where = "/sys/fs/pstore",
                .type = "pstore",
                .flags = MS_NOSUID|MS_NOEXEC|MS_NODEV,
        },
#endif
#if ENABLE_EFI
        {
                .what = "efivarfs",
                .where = "/sys/firmware/efi/efivars",
                .type = "efivarfs",
                .flags = MS_NOSUID|MS_NOEXEC|MS_NODEV,
                .condition_fn = is_efi_boot,
        },
#endif
        {
                .what = "bpf",
                .where = "/sys/fs/bpf",
                .type = "bpf",
                .options = "mode=0700",
                .flags = MS_NOSUID|MS_NOEXEC|MS_NODEV,
        },
};

/* The first three entries we might need before SELinux is up. The
 * fourth (securityfs) is needed by IMA to load a custom policy. The
 * other ones we can delay until SELinux and IMA are loaded. When
 * SMACK is enabled we need smackfs, too, so it's a fifth one. */
#if ENABLE_SMACK
#define N_EARLY_MOUNT 5
#else
#define N_EARLY_MOUNT 4
#endif

assert_cc(N_EARLY_MOUNT <= ELEMENTSOF(mount_table));

bool mount_point_is_api(const char *path) {
        /* Checks if this mount point is considered "API", and hence
         * should be ignored */

        FOREACH_ELEMENT(i, mount_table)
                if (path_equal(path, i->where))
                        return true;

        return path_startswith(path, "/sys/fs/cgroup/");
}

bool mount_point_ignore(const char *path) {
        /* These are API file systems that might be mounted by other software, we just list them here so that
         * we know that we should ignore them. */
        FOREACH_STRING(i,
                       /* SELinux file systems */
                       "/sys/fs/selinux",
                       /* Container bind mounts */
                       "/dev/console",
                       "/proc/kmsg",
                       "/proc/sys",
                       "/proc/sys/kernel/random/boot_id")
                if (path_equal(path, i))
                        return true;

        if (path_startswith(path, "/run/host")) /* All mounts passed in from the container manager are
                                                 * something we better ignore. */
                return true;

        return false;
}

static int mount_one(const MountPoint *p, bool relabel) {
        int r, priority;

        assert(p);
        assert(p->what);
        assert(p->where);
        assert(p->type);

        priority = FLAGS_SET(p->mode, MNT_FATAL) ? LOG_ERR : LOG_DEBUG;

        if (p->condition_fn && !p->condition_fn())
                return 0;

        /* Relabel first, just in case */
        if (relabel)
                (void) label_fix(p->where, LABEL_IGNORE_ENOENT|LABEL_IGNORE_EROFS);

        r = path_is_mount_point_full(p->where, /* root= */ NULL, AT_SYMLINK_FOLLOW);
        if (r < 0 && r != -ENOENT) {
                log_full_errno(priority, r, "Failed to determine whether %s is a mount point: %m", p->where);
                return FLAGS_SET(p->mode, MNT_FATAL) ? r : 0;
        }
        if (r > 0)
                return 0;

        if (!FLAGS_SET(p->mode, MNT_IN_CONTAINER) && detect_container() > 0)
                return 0;

        /* The access mode here doesn't really matter too much, since
         * the mounted file system will take precedence anyway. */
        if (relabel)
                (void) mkdir_p_label(p->where, 0755);
        else
                (void) mkdir_p(p->where, 0755);

        _cleanup_free_ char *extend_options = NULL;
        const char *o;
        if (p->options_fn) {
                r = p->options_fn(priority, p->type, &extend_options);
                if (r < 0)
                        return r;

                if (!strprepend_with_separator(&extend_options, ",", p->options))
                        return log_oom();

                o = extend_options;
        } else
                o = p->options;

        r = mount_verbose_full(priority, p->what, p->where, p->type, p->flags, o, FLAGS_SET(p->mode, MNT_FOLLOW_SYMLINK));
        if (r < 0)
                return FLAGS_SET(p->mode, MNT_FATAL) ? r : 0;

        /* Relabel again, since we now mounted something fresh here */
        if (relabel)
                (void) label_fix(p->where, 0);

        if (FLAGS_SET(p->mode, MNT_CHECK_WRITABLE))
                if (access(p->where, W_OK) < 0) {
                        r = -errno;

                        (void) umount2(p->where, UMOUNT_NOFOLLOW);
                        (void) rmdir(p->where);

                        log_full_errno(priority, r, "Mount point '%s' not writable after mounting, undoing: %m", p->where);
                        return FLAGS_SET(p->mode, MNT_FATAL) ? r : 0;
                }

        return 1;
}

static int mount_points_setup(size_t n, bool loaded_policy) {
        int r = 0;

        assert(n <= ELEMENTSOF(mount_table));

        FOREACH_ARRAY(mp, mount_table, n)
                RET_GATHER(r, mount_one(mp, loaded_policy));

        return r;
}

int mount_setup_early(void) {
        /* Do a minimal mount of /proc and friends to enable the most basic stuff, such as SELinux */
        return mount_points_setup(N_EARLY_MOUNT, /* loaded_policy= */ false);
}

#if HAVE_SELINUX || ENABLE_SMACK
static int relabel_cb(
                RecurseDirEvent event,
                const char *path,
                int dir_fd,
                int inode_fd,
                const struct dirent *de,
                const struct statx *sx,
                void *userdata) {

        switch (event) {

        case RECURSE_DIR_LEAVE:
        case RECURSE_DIR_SKIP_MOUNT:
                /* If we already saw this dirent when entering it or this is a dirent that on a different
                 * mount, don't relabel it. */
                return RECURSE_DIR_CONTINUE;

        case RECURSE_DIR_ENTER:
                /* /run/initramfs/ + /run/nextroot/ are static data and big, no need to dynamically relabel
                 * its contents at boot... */
                if (PATH_STARTSWITH_SET(path, "/run/initramfs", "/run/nextroot"))
                        return RECURSE_DIR_SKIP_ENTRY;

                _fallthrough_;

        default:
                /* Otherwise, label it, even if we had trouble stat()ing it and similar. SELinux can figure this out */
                (void) label_fix(path, 0);
                return RECURSE_DIR_CONTINUE;
        }
}

static int relabel_tree(const char *path) {
        int r;

        r = recurse_dir_at(AT_FDCWD, path, 0, UINT_MAX, RECURSE_DIR_ENSURE_TYPE|RECURSE_DIR_SAME_MOUNT, relabel_cb, NULL);
        if (r < 0)
                log_debug_errno(r, "Failed to recursively relabel '%s': %m", path);

        return r;
}

static int relabel_extra(void) {
        _cleanup_strv_free_ char **files = NULL;
        int r, c = 0;

        /* Support for relabelling additional files or directories after loading the policy. For this, code in the
         * initrd simply has to drop in *.relabel files into /run/systemd/relabel-extra.d/. We'll read all such files
         * expecting one absolute path by line and will relabel each (and everyone below that in case the path refers
         * to a directory). These drop-in files are supposed to be absolutely minimal, and do not understand comments
         * and such. After the operation succeeded the files are removed, and the drop-in directory as well, if
         * possible.
         */

        r = conf_files_list(&files, ".relabel", NULL,
                            CONF_FILES_FILTER_MASKED | CONF_FILES_REGULAR,
                            "/run/systemd/relabel-extra.d/");
        if (r < 0)
                return log_error_errno(r, "Failed to enumerate /run/systemd/relabel-extra.d/, ignoring: %m");

        STRV_FOREACH(file, files) {
                _cleanup_fclose_ FILE *f = NULL;

                f = fopen(*file, "re");
                if (!f) {
                        log_warning_errno(errno, "Failed to open %s, ignoring: %m", *file);
                        continue;
                }

                for (;;) {
                        _cleanup_free_ char *line = NULL;

                        r = read_line(f, LONG_LINE_MAX, &line);
                        if (r < 0) {
                                log_warning_errno(r, "Failed to read %s, ignoring: %m", *file);
                                break;
                        }
                        if (r == 0) /* EOF */
                                break;

                        path_simplify(line);

                        if (!path_is_normalized(line)) {
                                log_warning("Path to relabel is not normalized, ignoring: %s", line);
                                continue;
                        }

                        if (!path_is_absolute(line)) {
                                log_warning("Path to relabel is not absolute, ignoring: %s", line);
                                continue;
                        }

                        log_debug("Relabelling additional file/directory '%s'.", line);
                        (void) label_fix(line, 0);
                        (void) relabel_tree(line);
                        c++;
                }

                if (unlink(*file) < 0)
                        log_warning_errno(errno, "Failed to remove %s, ignoring: %m", *file);
        }

        /* Remove when we complete things. */
        if (rmdir("/run/systemd/relabel-extra.d") < 0 &&
            errno != ENOENT)
                log_warning_errno(errno, "Failed to remove /run/systemd/relabel-extra.d/ directory: %m");

        return c;
}
#endif

int mount_setup(bool loaded_policy, bool leave_propagation) {
        int r;

        r = mount_points_setup(ELEMENTSOF(mount_table), loaded_policy);
        if (r < 0)
                return r;

#if HAVE_SELINUX || ENABLE_SMACK
        /* Nodes in devtmpfs and /run need to be manually updated for
         * the appropriate labels, after mounting. The other virtual
         * API file systems like /sys and /proc do not need that, they
         * use the same label for all their files. */
        if (loaded_policy) {
                usec_t before_relabel, after_relabel;
                int n_extra;

                before_relabel = now(CLOCK_MONOTONIC);

                FOREACH_STRING(i, "/dev", "/dev/shm", "/run")
                        (void) relabel_tree(i);

                n_extra = relabel_extra();

                after_relabel = now(CLOCK_MONOTONIC);

                log_info("Relabeled /dev/, /dev/shm/, /run/%s in %s.",
                         n_extra > 0 ? ", and additional files" : "",
                         FORMAT_TIMESPAN(after_relabel - before_relabel, 0));
        }
#endif

        /* Create a few default symlinks, which are normally created
         * by udevd, but some scripts might need them before we start
         * udevd. */
        dev_setup(NULL, UID_INVALID, GID_INVALID);

        /* Mark the root directory as shared in regards to mount propagation. The kernel defaults to "private", but we
         * think it makes more sense to have a default of "shared" so that nspawn and the container tools work out of
         * the box. If specific setups need other settings they can reset the propagation mode to private if
         * needed. Note that we set this only when we are invoked directly by the kernel. If we are invoked by a
         * container manager we assume the container manager knows what it is doing (for example, because it set up
         * some directories with different propagation modes). */
        if (detect_container() <= 0 && !leave_propagation)
                if (mount(NULL, "/", NULL, MS_REC|MS_SHARED, NULL) < 0)
                        log_warning_errno(errno, "Failed to set up the root directory for shared mount propagation: %m");

        /* Create a few directories we always want around, Note that sd_booted() checks for /run/systemd/system, so
         * this mkdir really needs to stay for good, otherwise software that copied sd-daemon.c into their sources will
         * misdetect systemd. */
        (void) mkdir_label("/run/systemd", 0755);
        (void) mkdir_label("/run/systemd/system", 0755);

        /* Make sure there's always a place where sandboxed environments can mount root file systems they are
         * about to move into, even when unprivileged, without having to create a temporary one in /tmp/
         * (which they then have to keep track of and clean) */
        (void) mkdir_label("/run/systemd/mount-rootfs", 0555);

        /* Make sure we have a mount point to hide in sandboxes */
        (void) mkdir_label("/run/credentials", 0755);

        /* Also create /run/systemd/inaccessible nodes, so that we always have something to mount
         * inaccessible nodes from. If we run in a container the host might have created these for us already
         * in /run/host/inaccessible/. Use those if we can, since that way we likely get access to block/char
         * device nodes that are inaccessible, and if userns is used to nodes that are on mounts owned by a
         * userns outside the container and thus nicely read-only and not remountable. */
        if (access("/run/host/inaccessible/", F_OK) < 0) {
                if (errno != ENOENT)
                        log_debug_errno(errno, "Failed to check if /run/host/inaccessible exists, ignoring: %m");

                (void) make_inaccessible_nodes("/run/systemd", UID_INVALID, GID_INVALID);
        } else
                (void) symlink("../host/inaccessible", "/run/systemd/inaccessible");

        return 0;
}

1	/* SPDX-License-Identifier: LGPL-2.1-or-later */
2
3	#include <sys/mount.h>
4	#include <unistd.h>
5
6	#include "alloc-util.h"
7	#include "conf-files.h"
8	#include "dev-setup.h"
9	#include "efivars.h"
10	#include "errno-util.h"
11	#include "fd-util.h"
12	#include "fileio.h"
13	#include "label-util.h"
14	#include "log.h"
15	#include "mkdir-label.h"
16	#include "mount-setup.h"
17	#include "mount-util.h"
18	#include "mountpoint-util.h"
19	#include "path-util.h"
20	#include "recurse-dir.h"
21	#include "smack-util.h"
22	#include "string-util.h"
23	#include "strv.h"
24	#include "time-util.h"
25	#include "virt.h"
26
27	typedef enum MountMode {
28	MNT_FATAL = 1 << 0,
29	MNT_IN_CONTAINER = 1 << 1,
30	MNT_CHECK_WRITABLE = 1 << 2,
31	MNT_FOLLOW_SYMLINK = 1 << 3,
32	} MountMode;
33
34	typedef struct MountPoint {
35	const char *what;
36	const char *where;
37	const char *type;
38	const char *options;
39	int (options_fn)(int priority, const char type, char **ret);
40	unsigned long flags;
41	MountMode mode;
42	bool (*condition_fn)(void);
43	} MountPoint;
44
45	static int cgroupfs_mount_options(int priority, const char type, char *ret) {	148✔
46	int r;	148✔
47
48	assert(type);	148✔
49	assert(streq(type, "cgroup2"));	148✔
50	assert(ret);	148✔
51
52	/* memory_hugetlb_accounting mount option is since kernel v6.7 (8cba9576df601c384abd334a503c3f6e1e29eefb). */
53
54	r = mount_option_supported("cgroup2", "memory_hugetlb_accounting", /* value= */ NULL);	148✔
55	if (r <= 0) {	148✔
UNCOV 56	if (r < 0)	×
NEW 57	log_full_errno(priority, r, "Failed to determine whether cgroupfs supports 'memory_hugetlb_accounting' mount option, assuming not: %m");	×
58	else
NEW 59	log_debug("'memory_hugetlb_accounting' not supported by cgroupfs, not using mount option.");	×
60
NEW 61	*ret = NULL;	×
NEW 62	return 0;	×
63	}
64
65	return strdup_to(ret, "memory_hugetlb_accounting");	148✔
66	}
67
68	int mount_cgroupfs(const char *path) {	134✔
69	int r;	134✔
70
71	assert(path);	134✔
72
73	/* Mount a separate cgroupfs instance, taking all options we initial set into account. This is
74	* especially useful when cgroup namespace is not employed, since the kernel overrides all
75	* previous options if a new mount is established in initial cgns (c.f.
76	* https://github.com/torvalds/linux/blob/b69bb476dee99d564d65d418e9a20acca6f32c3f/kernel/cgroup/cgroup.c#L1984)
77	*/
78
79	_cleanup_free_ char *opts = NULL;	134✔
80	r = cgroupfs_mount_options(LOG_WARNING, "cgroup2", &opts);	134✔
81	if (r < 0)	134✔
82	return r;
83
84	/* These options shall be kept in sync with those in mount_table below. */
85	if (!strprepend_with_separator(&opts, ",", "nsdelegate,memory_recursiveprot"))	268✔
86	return log_oom();	×
87
88	return mount_nofollow_verbose(LOG_ERR, "cgroup2", path, "cgroup2", MS_NOSUID\|MS_NOEXEC\|MS_NODEV, opts);	134✔
89	}
90
91	static int usrquota_mount_option(int priority, const char type, char *ret) {	14✔
92	_cleanup_free_ char *o = NULL;	14✔
93	int r;	14✔
94
95	assert(type);	14✔
96	assert(ret);	14✔
97
98	r = mount_option_supported(type, "usrquota", /* value= */ NULL);	14✔
99	if (r < 0)	14✔
100	log_full_errno(priority, r, "Unable to determine whether %s supports 'usrquota' mount option, assuming not: %m", type);	×
101	else if (r == 0)	14✔
102	log_debug("Not enabling 'usrquota' for '%s' as kernel lacks support for it.", type);	×
103	else {
104	o = strdup("usrquota");	14✔
105	if (!o)	14✔
106	return log_oom_full(priority);	×
107	}
108
109	*ret = TAKE_PTR(o);	14✔
110	return 0;	14✔
111	}
112
113	static const MountPoint mount_table[] = {
114	{
115	.what = "proc",
116	.where = "/proc",
117	.type = "proc",
118	.flags = MS_NOSUID\|MS_NOEXEC\|MS_NODEV,
119	.mode = MNT_FATAL\|MNT_IN_CONTAINER\|MNT_FOLLOW_SYMLINK,
120	},
121	{
122	.what = "sysfs",
123	.where = "/sys",
124	.type = "sysfs",
125	.flags = MS_NOSUID\|MS_NOEXEC\|MS_NODEV,
126	.mode = MNT_FATAL\|MNT_IN_CONTAINER,
127	},
128	{
129	.what = "devtmpfs",
130	.where = "/dev",
131	.type = "devtmpfs",
132	.options = "mode=0755" TMPFS_LIMITS_DEV,
133	.flags = MS_NOSUID\|MS_STRICTATIME,
134	.mode = MNT_FATAL\|MNT_IN_CONTAINER,
135	},
136	{
137	.what = "securityfs",
138	.where = "/sys/kernel/security",
139	.type = "securityfs",
140	.flags = MS_NOSUID\|MS_NOEXEC\|MS_NODEV,
141	},
142	#if ENABLE_SMACK
143	{
144	.what = "smackfs",
145	.where = "/sys/fs/smackfs",
146	.type = "smackfs",
147	.options = "smackfsdef=*",
148	.flags = MS_NOSUID\|MS_NOEXEC\|MS_NODEV,
149	.mode = MNT_FATAL,
150	.condition_fn = mac_smack_use,
151	},
152	{
153	.what = "tmpfs",
154	.where = "/dev/shm",
155	.type = "tmpfs",
156	.options = "mode=01777,smackfsroot=*",
157	.options_fn = usrquota_mount_option,
158	.flags = MS_NOSUID\|MS_NODEV\|MS_STRICTATIME,
159	.mode = MNT_FATAL,
160	.condition_fn = mac_smack_use,
161	},
162	#endif
163	{
164	.what = "tmpfs",
165	.where = "/dev/shm",
166	.type = "tmpfs",
167	.options = "mode=01777",
168	.options_fn = usrquota_mount_option,
169	.flags = MS_NOSUID\|MS_NODEV\|MS_STRICTATIME,
170	.mode = MNT_FATAL\|MNT_IN_CONTAINER,
171	},
172	{
173	.what = "devpts",
174	.where = "/dev/pts",
175	.type = "devpts",
176	.options = "mode=" STRINGIFY(TTY_MODE) ",gid=" STRINGIFY(TTY_GID),
177	.flags = MS_NOSUID\|MS_NOEXEC,
178	.mode = MNT_IN_CONTAINER,
179	},
180	#if ENABLE_SMACK
181	{
182	.what = "tmpfs",
183	.where = "/run",
184	.type = "tmpfs",
185	.options = "mode=0755,smackfsroot=*" TMPFS_LIMITS_RUN,
186	.flags = MS_NOSUID\|MS_NODEV\|MS_STRICTATIME,
187	.mode = MNT_FATAL,
188	.condition_fn = mac_smack_use,
189	},
190	#endif
191	{
192	.what = "tmpfs",
193	.where = "/run",
194	.type = "tmpfs",
195	.options = "mode=0755" TMPFS_LIMITS_RUN,
196	.flags = MS_NOSUID\|MS_NODEV\|MS_STRICTATIME,
197	.mode = MNT_FATAL\|MNT_IN_CONTAINER,
198	},
199	{
200	.what = "cgroup2",
201	.where = "/sys/fs/cgroup",
202	.type = "cgroup2",
203	.options = "nsdelegate,memory_recursiveprot",
204	.options_fn = cgroupfs_mount_options,
205	.flags = MS_NOSUID\|MS_NOEXEC\|MS_NODEV,
206	.mode = MNT_FATAL\|MNT_IN_CONTAINER\|MNT_CHECK_WRITABLE,
207	},
208	#if ENABLE_PSTORE
209	{
210	.what = "pstore",
211	.where = "/sys/fs/pstore",
212	.type = "pstore",
213	.flags = MS_NOSUID\|MS_NOEXEC\|MS_NODEV,
214	},
215	#endif
216	#if ENABLE_EFI
217	{
218	.what = "efivarfs",
219	.where = "/sys/firmware/efi/efivars",
220	.type = "efivarfs",
221	.flags = MS_NOSUID\|MS_NOEXEC\|MS_NODEV,
222	.condition_fn = is_efi_boot,
223	},
224	#endif
225	{
226	.what = "bpf",
227	.where = "/sys/fs/bpf",
228	.type = "bpf",
229	.options = "mode=0700",
230	.flags = MS_NOSUID\|MS_NOEXEC\|MS_NODEV,
231	},
232	};
233
234	/* The first three entries we might need before SELinux is up. The
235	* fourth (securityfs) is needed by IMA to load a custom policy. The
236	* other ones we can delay until SELinux and IMA are loaded. When
237	* SMACK is enabled we need smackfs, too, so it's a fifth one. */
238	#if ENABLE_SMACK
239	#define N_EARLY_MOUNT 5
240	#else
241	#define N_EARLY_MOUNT 4
242	#endif
243
244	assert_cc(N_EARLY_MOUNT <= ELEMENTSOF(mount_table));
245
246	bool mount_point_is_api(const char *path) {	150,852✔
247	/* Checks if this mount point is considered "API", and hence
248	* should be ignored */
249
250	FOREACH_ELEMENT(i, mount_table)	1,923,945✔
251	if (path_equal(path, i->where))	1,814,419✔
252	return true;
253
254	return path_startswith(path, "/sys/fs/cgroup/");	109,526✔
255	}
256
257	bool mount_point_ignore(const char *path) {	109,514✔
258	/* These are API file systems that might be mounted by other software, we just list them here so that
259	* we know that we should ignore them. */
260	FOREACH_STRING(i,	647,466✔
261	/* SELinux file systems */
262	"/sys/fs/selinux",
263	/* Container bind mounts */
264	"/dev/console",
265	"/proc/kmsg",
266	"/proc/sys",
267	"/proc/sys/kernel/random/boot_id")
268	if (path_equal(path, i))	543,448✔
269	return true;	5,496✔
270
271	if (path_startswith(path, "/run/host")) /* All mounts passed in from the container manager are	104,018✔
272	* something we better ignore. */
273	return true;	8,244✔
274
275	return false;
276	}
277
278	static int mount_one(const MountPoint *p, bool relabel) {	813✔
279	int r, priority;	813✔
280
281	assert(p);	813✔
282	assert(p->what);	813✔
283	assert(p->where);	813✔
284	assert(p->type);	813✔
285
286	priority = FLAGS_SET(p->mode, MNT_FATAL) ? LOG_ERR : LOG_DEBUG;	813✔
287
288	if (p->condition_fn && !p->condition_fn())	813✔
289	return 0;	813✔
290
291	/* Relabel first, just in case */
292	if (relabel)	600✔
293	(void) label_fix(p->where, LABEL_IGNORE_ENOENT\|LABEL_IGNORE_EROFS);	×
294
295	r = path_is_mount_point_full(p->where, /* root= */ NULL, AT_SYMLINK_FOLLOW);	600✔
296	if (r < 0 && r != -ENOENT) {	600✔
297	log_full_errno(priority, r, "Failed to determine whether %s is a mount point: %m", p->where);	×
298	return FLAGS_SET(p->mode, MNT_FATAL) ? r : 0;	×
299	}
300	if (r > 0)	600✔
301	return 0;
302
303	if (!FLAGS_SET(p->mode, MNT_IN_CONTAINER) && detect_container() > 0)	236✔
304	return 0;
305
306	/* The access mode here doesn't really matter too much, since
307	* the mounted file system will take precedence anyway. */
308	if (relabel)	146✔
309	(void) mkdir_p_label(p->where, 0755);	×
310	else
311	(void) mkdir_p(p->where, 0755);	146✔
312
313	_cleanup_free_ char *extend_options = NULL;	146✔
314	const char *o;	146✔
315	if (p->options_fn) {	146✔
316	r = p->options_fn(priority, p->type, &extend_options);	28✔
317	if (r < 0)	28✔
318	return r;
319
320	if (!strprepend_with_separator(&extend_options, ",", p->options))	56✔
321	return log_oom();	×
322
323	o = extend_options;	28✔
324	} else
325	o = p->options;	118✔
326
327	r = mount_verbose_full(priority, p->what, p->where, p->type, p->flags, o, FLAGS_SET(p->mode, MNT_FOLLOW_SYMLINK));	146✔
328	if (r < 0)	146✔
329	return FLAGS_SET(p->mode, MNT_FATAL) ? r : 0;	×
330
331	/* Relabel again, since we now mounted something fresh here */
332	if (relabel)	146✔
333	(void) label_fix(p->where, 0);	×
334
335	if (FLAGS_SET(p->mode, MNT_CHECK_WRITABLE))	146✔
336	if (access(p->where, W_OK) < 0) {	14✔
337	r = -errno;	×
338
339	(void) umount2(p->where, UMOUNT_NOFOLLOW);	×
340	(void) rmdir(p->where);	×
341
342	log_full_errno(priority, r, "Mount point '%s' not writable after mounting, undoing: %m", p->where);	×
343	return FLAGS_SET(p->mode, MNT_FATAL) ? r : 0;	×
344	}
345
346	return 1;
347	}
348
349	static int mount_points_setup(size_t n, bool loaded_policy) {	69✔
350	int r = 0;	69✔
351
352	assert(n <= ELEMENTSOF(mount_table));	69✔
353
354	FOREACH_ARRAY(mp, mount_table, n)	882✔
355	RET_GATHER(r, mount_one(mp, loaded_policy));	813✔
356
357	return r;	69✔
358	}
359
360	int mount_setup_early(void) {	17✔
361	/* Do a minimal mount of /proc and friends to enable the most basic stuff, such as SELinux */
362	return mount_points_setup(N_EARLY_MOUNT, /* loaded_policy= */ false);	17✔
363	}
364
365	#if HAVE_SELINUX \|\| ENABLE_SMACK
366	static int relabel_cb(	×
367	RecurseDirEvent event,
368	const char *path,
369	int dir_fd,
370	int inode_fd,
371	const struct dirent *de,
372	const struct statx *sx,
373	void *userdata) {
374
375	switch (event) {	×
376
377	case RECURSE_DIR_LEAVE:
378	case RECURSE_DIR_SKIP_MOUNT:
379	/* If we already saw this dirent when entering it or this is a dirent that on a different
380	* mount, don't relabel it. */
381	return RECURSE_DIR_CONTINUE;
382
383	case RECURSE_DIR_ENTER:	×
384	/* /run/initramfs/ + /run/nextroot/ are static data and big, no need to dynamically relabel
385	* its contents at boot... */
386	if (PATH_STARTSWITH_SET(path, "/run/initramfs", "/run/nextroot"))	×
387	return RECURSE_DIR_SKIP_ENTRY;	×
388
389	_fallthrough_;	×
390
391	default:
392	/* Otherwise, label it, even if we had trouble stat()ing it and similar. SELinux can figure this out */
393	(void) label_fix(path, 0);	×
394	return RECURSE_DIR_CONTINUE;	×
395	}
396	}
397
398	static int relabel_tree(const char *path) {	×
399	int r;	×
400
401	r = recurse_dir_at(AT_FDCWD, path, 0, UINT_MAX, RECURSE_DIR_ENSURE_TYPE\|RECURSE_DIR_SAME_MOUNT, relabel_cb, NULL);	×
402	if (r < 0)	×
403	log_debug_errno(r, "Failed to recursively relabel '%s': %m", path);	×
404
405	return r;	×
406	}
407
408	static int relabel_extra(void) {	×
409	_cleanup_strv_free_ char **files = NULL;	×
410	int r, c = 0;	×
411
412	/* Support for relabelling additional files or directories after loading the policy. For this, code in the
413	* initrd simply has to drop in *.relabel files into /run/systemd/relabel-extra.d/. We'll read all such files
414	* expecting one absolute path by line and will relabel each (and everyone below that in case the path refers
415	* to a directory). These drop-in files are supposed to be absolutely minimal, and do not understand comments
416	* and such. After the operation succeeded the files are removed, and the drop-in directory as well, if
417	* possible.
418	*/
419
420	r = conf_files_list(&files, ".relabel", NULL,	×
421	CONF_FILES_FILTER_MASKED \| CONF_FILES_REGULAR,
422	"/run/systemd/relabel-extra.d/");
423	if (r < 0)	×
424	return log_error_errno(r, "Failed to enumerate /run/systemd/relabel-extra.d/, ignoring: %m");	×
425
426	STRV_FOREACH(file, files) {	×
427	_cleanup_fclose_ FILE *f = NULL;	×
428
429	f = fopen(*file, "re");	×
430	if (!f) {	×
431	log_warning_errno(errno, "Failed to open %s, ignoring: %m", *file);	×
432	continue;	×
433	}
434
435	for (;;) {	×
436	_cleanup_free_ char *line = NULL;	×
437
438	r = read_line(f, LONG_LINE_MAX, &line);	×
439	if (r < 0) {	×
440	log_warning_errno(r, "Failed to read %s, ignoring: %m", *file);	×
441	break;
442	}
443	if (r == 0) /* EOF */	×
444	break;
445
446	path_simplify(line);	×
447
448	if (!path_is_normalized(line)) {	×
449	log_warning("Path to relabel is not normalized, ignoring: %s", line);	×
450	continue;	×
451	}
452
453	if (!path_is_absolute(line)) {	×
454	log_warning("Path to relabel is not absolute, ignoring: %s", line);	×
455	continue;	×
456	}
457
458	log_debug("Relabelling additional file/directory '%s'.", line);	×
459	(void) label_fix(line, 0);	×
460	(void) relabel_tree(line);	×
461	c++;	×
462	}
463
464	if (unlink(*file) < 0)	×
465	log_warning_errno(errno, "Failed to remove %s, ignoring: %m", *file);	×
466	}
467
468	/* Remove when we complete things. */
469	if (rmdir("/run/systemd/relabel-extra.d") < 0 &&	×
470	errno != ENOENT)	×
471	log_warning_errno(errno, "Failed to remove /run/systemd/relabel-extra.d/ directory: %m");	×
472
473	return c;
474	}
475	#endif
476
477	int mount_setup(bool loaded_policy, bool leave_propagation) {	52✔
478	int r;	52✔
479
480	r = mount_points_setup(ELEMENTSOF(mount_table), loaded_policy);	52✔
481	if (r < 0)	52✔
482	return r;
483
484	#if HAVE_SELINUX \|\| ENABLE_SMACK
485	/* Nodes in devtmpfs and /run need to be manually updated for
486	* the appropriate labels, after mounting. The other virtual
487	* API file systems like /sys and /proc do not need that, they
488	* use the same label for all their files. */
489	if (loaded_policy) {	52✔
490	usec_t before_relabel, after_relabel;	×
491	int n_extra;	×
492
493	before_relabel = now(CLOCK_MONOTONIC);	×
494
495	FOREACH_STRING(i, "/dev", "/dev/shm", "/run")	×
496	(void) relabel_tree(i);	×
497
498	n_extra = relabel_extra();	×
499
500	after_relabel = now(CLOCK_MONOTONIC);	×
501
502	log_info("Relabeled /dev/, /dev/shm/, /run/%s in %s.",	×
503	n_extra > 0 ? ", and additional files" : "",
504	FORMAT_TIMESPAN(after_relabel - before_relabel, 0));
505	}
506	#endif
507
508	/* Create a few default symlinks, which are normally created
509	* by udevd, but some scripts might need them before we start
510	* udevd. */
511	dev_setup(NULL, UID_INVALID, GID_INVALID);	52✔
512
513	/* Mark the root directory as shared in regards to mount propagation. The kernel defaults to "private", but we
514	* think it makes more sense to have a default of "shared" so that nspawn and the container tools work out of
515	* the box. If specific setups need other settings they can reset the propagation mode to private if
516	* needed. Note that we set this only when we are invoked directly by the kernel. If we are invoked by a
517	* container manager we assume the container manager knows what it is doing (for example, because it set up
518	* some directories with different propagation modes). */
519	if (detect_container() <= 0 && !leave_propagation)	52✔
520	if (mount(NULL, "/", NULL, MS_REC\|MS_SHARED, NULL) < 0)	17✔
521	log_warning_errno(errno, "Failed to set up the root directory for shared mount propagation: %m");	×
522
523	/* Create a few directories we always want around, Note that sd_booted() checks for /run/systemd/system, so
524	* this mkdir really needs to stay for good, otherwise software that copied sd-daemon.c into their sources will
525	* misdetect systemd. */
526	(void) mkdir_label("/run/systemd", 0755);	52✔
527	(void) mkdir_label("/run/systemd/system", 0755);	52✔
528
529	/* Make sure there's always a place where sandboxed environments can mount root file systems they are
530	* about to move into, even when unprivileged, without having to create a temporary one in /tmp/
531	* (which they then have to keep track of and clean) */
532	(void) mkdir_label("/run/systemd/mount-rootfs", 0555);	52✔
533
534	/* Make sure we have a mount point to hide in sandboxes */
535	(void) mkdir_label("/run/credentials", 0755);	52✔
536
537	/* Also create /run/systemd/inaccessible nodes, so that we always have something to mount
538	* inaccessible nodes from. If we run in a container the host might have created these for us already
539	* in /run/host/inaccessible/. Use those if we can, since that way we likely get access to block/char
540	* device nodes that are inaccessible, and if userns is used to nodes that are on mounts owned by a
541	* userns outside the container and thus nicely read-only and not remountable. */
542	if (access("/run/host/inaccessible/", F_OK) < 0) {	52✔
543	if (errno != ENOENT)	22✔
544	log_debug_errno(errno, "Failed to check if /run/host/inaccessible exists, ignoring: %m");	×
545
546	(void) make_inaccessible_nodes("/run/systemd", UID_INVALID, GID_INVALID);	22✔
547	} else
548	(void) symlink("../host/inaccessible", "/run/systemd/inaccessible");	30✔
549
550	return 0;
551	}

systemd / systemd / 20977275812

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