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Diffstat (limited to 'src/nspawn/nspawn.c')
-rw-r--r--src/nspawn/nspawn.c183
1 files changed, 122 insertions, 61 deletions
diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c
index 3e32f59f75..40e3d5a3fe 100644
--- a/src/nspawn/nspawn.c
+++ b/src/nspawn/nspawn.c
@@ -181,10 +181,9 @@ static char *arg_image = NULL;
static VolatileMode arg_volatile_mode = VOLATILE_NO;
static ExposePort *arg_expose_ports = NULL;
static char **arg_property = NULL;
-static bool arg_userns = false;
-static bool arg_userns_chown = false;
+static UserNamespaceMode arg_userns_mode = USER_NAMESPACE_NO;
static uid_t arg_uid_shift = UID_INVALID, arg_uid_range = 0x10000U;
-static bool arg_uid_shift_pick = false;
+static bool arg_userns_chown = false;
static int arg_kill_signal = 0;
static bool arg_unified_cgroup_hierarchy = false;
static SettingsMask arg_settings_mask = 0;
@@ -284,7 +283,7 @@ static int custom_mounts_prepare(void) {
for (i = 0; i < arg_n_custom_mounts; i++) {
CustomMount *m = &arg_custom_mounts[i];
- if (path_equal(m->destination, "/") && arg_userns) {
+ if (path_equal(m->destination, "/") && arg_userns_mode != USER_NAMESPACE_NO) {
if (arg_userns_chown) {
log_error("--private-users-chown may not be combined with custom root mounts.");
@@ -817,56 +816,67 @@ static int parse_argv(int argc, char *argv[]) {
break;
case ARG_PRIVATE_USERS:
- if (optarg) {
+
+ r = optarg ? parse_boolean(optarg) : 1;
+ if (r == 0) {
+ /* no: User namespacing off */
+ arg_userns_mode = USER_NAMESPACE_NO;
+ arg_uid_shift = UID_INVALID;
+ arg_uid_range = UINT32_C(0x10000);
+ } else if (r > 0) {
+ /* yes: User namespacing on, UID range is read from root dir */
+ arg_userns_mode = USER_NAMESPACE_FIXED;
+ arg_uid_shift = UID_INVALID;
+ arg_uid_range = UINT32_C(0x10000);
+ } else if (streq(optarg, "pick")) {
+ /* pick: User namespacing on, UID range is picked randomly */
+ arg_userns_mode = USER_NAMESPACE_PICK;
+ arg_uid_shift = UID_INVALID;
+ arg_uid_range = UINT32_C(0x10000);
+ } else {
_cleanup_free_ char *buffer = NULL;
const char *range, *shift;
- if (streq(optarg, "pick")) {
- arg_uid_shift = UID_INVALID;
- arg_uid_range = 0x10000U;
- arg_uid_shift_pick = true;
- } else {
- range = strchr(optarg, ':');
- if (range) {
- buffer = strndup(optarg, range - optarg);
- if (!buffer)
- return log_oom();
- shift = buffer;
-
- range++;
- if (safe_atou32(range, &arg_uid_range) < 0 || arg_uid_range <= 0) {
- log_error("Failed to parse UID range: %s", range);
- return -EINVAL;
- }
- } else
- shift = optarg;
-
- if (parse_uid(shift, &arg_uid_shift) < 0) {
- log_error("Failed to parse UID: %s", optarg);
+ /* anything else: User namespacing on, UID range is explicitly configured */
+
+ range = strchr(optarg, ':');
+ if (range) {
+ buffer = strndup(optarg, range - optarg);
+ if (!buffer)
+ return log_oom();
+ shift = buffer;
+
+ range++;
+ if (safe_atou32(range, &arg_uid_range) < 0 || arg_uid_range <= 0) {
+ log_error("Failed to parse UID range: %s", range);
return -EINVAL;
}
+ } else
+ shift = optarg;
- arg_uid_shift_pick = false;
+ if (parse_uid(shift, &arg_uid_shift) < 0) {
+ log_error("Failed to parse UID: %s", optarg);
+ return -EINVAL;
}
- } else {
- arg_uid_shift = UID_INVALID;
- arg_uid_range = 0x10000U;
- arg_uid_shift_pick = false;
+
+ arg_userns_mode = USER_NAMESPACE_FIXED;
}
- arg_userns = true;
+ arg_settings_mask |= SETTING_USERNS;
break;
- case ARG_PRIVATE_USERS_CHOWN:
- arg_userns_chown = true;
+ case 'U':
+ arg_userns_mode = USER_NAMESPACE_PICK;
+ arg_uid_shift = UID_INVALID;
+ arg_uid_range = UINT32_C(0x10000);
+
+ arg_settings_mask |= SETTING_USERNS;
break;
- case 'U':
- arg_userns = true;
+ case ARG_PRIVATE_USERS_CHOWN:
arg_userns_chown = true;
- arg_uid_shift = UID_INVALID;
- arg_uid_range = 0x10000U;
- arg_uid_shift_pick = true;
+
+ arg_settings_mask |= SETTING_USERNS;
break;
case ARG_KILL_SIGNAL:
@@ -937,7 +947,7 @@ static int parse_argv(int argc, char *argv[]) {
if (arg_share_system)
arg_register = false;
- if (arg_uid_shift_pick)
+ if (arg_userns_mode == USER_NAMESPACE_PICK)
arg_userns_chown = true;
if (arg_start_mode != START_PID1 && arg_share_system) {
@@ -980,7 +990,7 @@ static int parse_argv(int argc, char *argv[]) {
return -EINVAL;
}
- if (arg_userns && access("/proc/self/uid_map", F_OK) < 0) {
+ if (arg_userns_mode != USER_NAMESPACE_NO && access("/proc/self/uid_map", F_OK) < 0) {
log_error("--private-users= is not supported, kernel compiled without user namespace support.");
return -EOPNOTSUPP;
}
@@ -1047,7 +1057,7 @@ static int verify_arguments(void) {
static int userns_lchown(const char *p, uid_t uid, gid_t gid) {
assert(p);
- if (!arg_userns)
+ if (arg_userns_mode == USER_NAMESPACE_NO)
return 0;
if (uid == UID_INVALID && gid == GID_INVALID)
@@ -2277,7 +2287,7 @@ static int recursive_chown(const char *directory, uid_t shift, uid_t range) {
assert(directory);
- if (!arg_userns || !arg_userns_chown)
+ if (arg_userns_mode == USER_NAMESPACE_NO || !arg_userns_chown)
return 0;
r = path_patch_uid(directory, arg_uid_shift, arg_uid_range);
@@ -2512,7 +2522,7 @@ static int determine_names(void) {
static int determine_uid_shift(const char *directory) {
int r;
- if (!arg_userns) {
+ if (arg_userns_mode == USER_NAMESPACE_NO) {
arg_uid_shift = 0;
return 0;
}
@@ -2575,7 +2585,7 @@ static int inner_child(
cg_unified_flush();
- if (arg_userns) {
+ if (arg_userns_mode != USER_NAMESPACE_NO) {
/* Tell the parent, that it now can write the UID map. */
(void) barrier_place(barrier); /* #1 */
@@ -2586,7 +2596,14 @@ static int inner_child(
}
}
- r = mount_all(NULL, arg_userns, true, arg_uid_shift, arg_private_network, arg_uid_range, arg_selinux_apifs_context);
+ r = mount_all(NULL,
+ arg_userns_mode != USER_NAMESPACE_NO,
+ true,
+ arg_private_network,
+ arg_uid_shift,
+ arg_uid_range,
+ arg_selinux_apifs_context);
+
if (r < 0)
return r;
@@ -2825,7 +2842,7 @@ static int outer_child(
if (r < 0)
return r;
- if (arg_userns) {
+ if (arg_userns_mode != USER_NAMESPACE_NO) {
/* Let the parent know which UID shift we read from the image */
l = send(uid_shift_socket, &arg_uid_shift, sizeof(arg_uid_shift), MSG_NOSIGNAL);
if (l < 0)
@@ -2835,7 +2852,7 @@ static int outer_child(
return -EIO;
}
- if (arg_uid_shift_pick) {
+ if (arg_userns_mode == USER_NAMESPACE_PICK) {
/* When we are supposed to pick the UID shift, the parent will check now whether the UID shift
* we just read from the image is available. If yes, it will send the UID shift back to us, if
* not it will pick a different one, and send it back to us. */
@@ -2860,11 +2877,23 @@ static int outer_child(
if (r < 0)
return r;
- r = setup_volatile(directory, arg_volatile_mode, arg_userns, arg_uid_shift, arg_uid_range, arg_selinux_context);
+ r = setup_volatile(
+ directory,
+ arg_volatile_mode,
+ arg_userns_mode != USER_NAMESPACE_NO,
+ arg_uid_shift,
+ arg_uid_range,
+ arg_selinux_context);
if (r < 0)
return r;
- r = setup_volatile_state(directory, arg_volatile_mode, arg_userns, arg_uid_shift, arg_uid_range, arg_selinux_context);
+ r = setup_volatile_state(
+ directory,
+ arg_volatile_mode,
+ arg_userns_mode != USER_NAMESPACE_NO,
+ arg_uid_shift,
+ arg_uid_range,
+ arg_selinux_context);
if (r < 0)
return r;
@@ -2878,7 +2907,13 @@ static int outer_child(
return log_error_errno(r, "Failed to make tree read-only: %m");
}
- r = mount_all(directory, arg_userns, false, arg_private_network, arg_uid_shift, arg_uid_range, arg_selinux_apifs_context);
+ r = mount_all(directory,
+ arg_userns_mode != USER_NAMESPACE_NO,
+ false,
+ arg_private_network,
+ arg_uid_shift,
+ arg_uid_range,
+ arg_selinux_apifs_context);
if (r < 0)
return r;
@@ -2920,11 +2955,24 @@ static int outer_child(
if (r < 0)
return r;
- r = mount_custom(directory, arg_custom_mounts, arg_n_custom_mounts, arg_userns, arg_uid_shift, arg_uid_range, arg_selinux_apifs_context);
+ r = mount_custom(
+ directory,
+ arg_custom_mounts,
+ arg_n_custom_mounts,
+ arg_userns_mode != USER_NAMESPACE_NO,
+ arg_uid_shift,
+ arg_uid_range,
+ arg_selinux_apifs_context);
if (r < 0)
return r;
- r = mount_cgroups(directory, arg_unified_cgroup_hierarchy, arg_userns, arg_uid_shift, arg_uid_range, arg_selinux_apifs_context);
+ r = mount_cgroups(
+ directory,
+ arg_unified_cgroup_hierarchy,
+ arg_userns_mode != USER_NAMESPACE_NO,
+ arg_uid_shift,
+ arg_uid_range,
+ arg_selinux_apifs_context);
if (r < 0)
return r;
@@ -2935,7 +2983,7 @@ static int outer_child(
pid = raw_clone(SIGCHLD|CLONE_NEWNS|
(arg_share_system ? 0 : CLONE_NEWIPC|CLONE_NEWPID|CLONE_NEWUTS) |
(arg_private_network ? CLONE_NEWNET : 0) |
- (arg_userns ? CLONE_NEWUSER : 0),
+ (arg_userns_mode != USER_NAMESPACE_NO ? CLONE_NEWUSER : 0),
NULL);
if (pid < 0)
return log_error_errno(errno, "Failed to fork inner child: %m");
@@ -2986,7 +3034,7 @@ static int uid_shift_pick(uid_t *shift, LockFile *ret_lock_file) {
assert(shift);
assert(ret_lock_file);
- assert(arg_uid_shift_pick);
+ assert(arg_userns_mode == USER_NAMESPACE_PICK);
assert(arg_uid_range == 0x10000U);
candidate = *shift;
@@ -3265,6 +3313,19 @@ static int load_settings(void) {
}
}
+ if ((arg_settings_mask & SETTING_USERNS) == 0 &&
+ settings->userns_mode != _USER_NAMESPACE_MODE_INVALID) {
+
+ if (!arg_settings_trusted)
+ log_warning("Ignoring PrivateUsers= and PrivateUsersChown= settings, file %s is not trusted.", p);
+ else {
+ arg_userns_mode = settings->userns_mode;
+ arg_uid_shift = settings->uid_shift;
+ arg_uid_range = settings->uid_range;
+ arg_userns_chown = settings->userns_chown;
+ }
+ }
+
return 0;
}
@@ -3525,7 +3586,7 @@ int main(int argc, char *argv[]) {
int ifi = 0;
ssize_t l;
- if (arg_uid_shift_pick) {
+ if (arg_userns_mode == USER_NAMESPACE_PICK) {
/* When we shall pick the UID/GID range, let's first lock /etc/passwd, so that we can safely
* check with getpwuid() if the specific user already exists. Note that /etc might be
* read-only, in which case this will fail with EROFS. But that's really OK, as in that case we
@@ -3566,7 +3627,7 @@ int main(int argc, char *argv[]) {
goto finish;
}
- if (arg_userns)
+ if (arg_userns_mode != USER_NAMESPACE_NO)
if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, uid_shift_socket_pair) < 0) {
r = log_error_errno(errno, "Failed to create uid shift socket pair: %m");
goto finish;
@@ -3642,7 +3703,7 @@ int main(int argc, char *argv[]) {
uuid_socket_pair[1] = safe_close(uuid_socket_pair[1]);
uid_shift_socket_pair[1] = safe_close(uid_shift_socket_pair[1]);
- if (arg_userns) {
+ if (arg_userns_mode != USER_NAMESPACE_NO) {
/* The child just let us know the UID shift it might have read from the image. */
l = recv(uid_shift_socket_pair[0], &arg_uid_shift, sizeof(arg_uid_shift), 0);
if (l < 0) {
@@ -3655,7 +3716,7 @@ int main(int argc, char *argv[]) {
goto finish;
}
- if (arg_uid_shift_pick) {
+ if (arg_userns_mode == USER_NAMESPACE_PICK) {
/* If we are supposed to pick the UID shift, let's try to use the shift read from the
* image, but if that's already in use, pick a new one, and report back to the child,
* which one we now picked. */
@@ -3715,7 +3776,7 @@ int main(int argc, char *argv[]) {
log_debug("Init process invoked as PID " PID_FMT, pid);
- if (arg_userns) {
+ if (arg_userns_mode != USER_NAMESPACE_NO) {
if (!barrier_place_and_sync(&barrier)) { /* #1 */
log_error("Child died too early.");
r = -ESRCH;
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-17 07:33:29 +0000