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-rw-r--r--src/nspawn/nspawn-gperf.gperf4
-rw-r--r--src/nspawn/nspawn-settings.c86
-rw-r--r--src/nspawn/nspawn-settings.h15
-rw-r--r--src/nspawn/nspawn.c183
4 files changed, 225 insertions, 63 deletions
diff --git a/src/nspawn/nspawn-gperf.gperf b/src/nspawn/nspawn-gperf.gperf
index 116655cdd2..34e1310e29 100644
--- a/src/nspawn/nspawn-gperf.gperf
+++ b/src/nspawn/nspawn-gperf.gperf
@@ -16,7 +16,7 @@ struct ConfigPerfItem;
%includes
%%
Exec.Boot, config_parse_boot, 0, 0
-Exec.ProcessTwo, config_parse_pid2, 0, 0,
+Exec.ProcessTwo, config_parse_pid2, 0, 0
Exec.Parameters, config_parse_strv, 0, offsetof(Settings, parameters)
Exec.Environment, config_parse_strv, 0, offsetof(Settings, environment)
Exec.User, config_parse_string, 0, offsetof(Settings, user)
@@ -26,11 +26,13 @@ Exec.KillSignal, config_parse_signal, 0, offsetof(Settings,
Exec.Personality, config_parse_personality, 0, offsetof(Settings, personality)
Exec.MachineID, config_parse_id128, 0, offsetof(Settings, machine_id)
Exec.WorkingDirectory, config_parse_path, 0, offsetof(Settings, working_directory)
+Exec.PrivateUsers, config_parse_private_users, 0, 0
Files.ReadOnly, config_parse_tristate, 0, offsetof(Settings, read_only)
Files.Volatile, config_parse_volatile_mode, 0, offsetof(Settings, volatile_mode)
Files.Bind, config_parse_bind, 0, 0
Files.BindReadOnly, config_parse_bind, 1, 0
Files.TemporaryFileSystem, config_parse_tmpfs, 0, 0
+Files.PrivateUsersChown, config_parse_tristate, 0, offsetof(Settings, userns_chown)
Network.Private, config_parse_tristate, 0, offsetof(Settings, private_network)
Network.Interface, config_parse_strv, 0, offsetof(Settings, network_interfaces)
Network.MACVLAN, config_parse_strv, 0, offsetof(Settings, network_macvlan)
diff --git a/src/nspawn/nspawn-settings.c b/src/nspawn/nspawn-settings.c
index 4fb0054698..b98a79fd09 100644
--- a/src/nspawn/nspawn-settings.c
+++ b/src/nspawn/nspawn-settings.c
@@ -25,7 +25,9 @@
#include "parse-util.h"
#include "process-util.h"
#include "strv.h"
+#include "user-util.h"
#include "util.h"
+#include "string-util.h"
int settings_load(FILE *f, const char *path, Settings **ret) {
_cleanup_(settings_freep) Settings *s = NULL;
@@ -40,9 +42,13 @@ int settings_load(FILE *f, const char *path, Settings **ret) {
s->start_mode = _START_MODE_INVALID;
s->personality = PERSONALITY_INVALID;
+ s->userns_mode = _USER_NAMESPACE_MODE_INVALID;
+ s->uid_shift = UID_INVALID;
+ s->uid_range = UID_INVALID;
s->read_only = -1;
s->volatile_mode = _VOLATILE_MODE_INVALID;
+ s->userns_chown = -1;
s->private_network = -1;
s->network_veth = -1;
@@ -59,6 +65,16 @@ int settings_load(FILE *f, const char *path, Settings **ret) {
if (r < 0)
return r;
+ /* Make sure that if userns_mode is set, userns_chown is set to something appropriate, and vice versa. Either
+ * both fields shall be initialized or neither. */
+ if (s->userns_mode == USER_NAMESPACE_PICK)
+ s->userns_chown = true;
+ else if (s->userns_mode != _USER_NAMESPACE_MODE_INVALID && s->userns_chown < 0)
+ s->userns_chown = false;
+
+ if (s->userns_chown >= 0 && s->userns_mode == _USER_NAMESPACE_MODE_INVALID)
+ s->userns_mode = USER_NAMESPACE_NO;
+
*ret = s;
s = NULL;
@@ -392,3 +408,73 @@ conflict:
log_syntax(unit, LOG_ERR, filename, line, r, "Conflicting Boot= or ProcessTwo= setting found. Ignoring.");
return 0;
}
+
+int config_parse_private_users(
+ const char *unit,
+ const char *filename,
+ unsigned line,
+ const char *section,
+ unsigned section_line,
+ const char *lvalue,
+ int ltype,
+ const char *rvalue,
+ void *data,
+ void *userdata) {
+
+ Settings *settings = data;
+ int r;
+
+ assert(filename);
+ assert(lvalue);
+ assert(rvalue);
+
+ r = parse_boolean(rvalue);
+ if (r == 0) {
+ /* no: User namespacing off */
+ settings->userns_mode = USER_NAMESPACE_NO;
+ settings->uid_shift = UID_INVALID;
+ settings->uid_range = UINT32_C(0x10000);
+ } else if (r > 0) {
+ /* yes: User namespacing on, UID range is read from root dir */
+ settings->userns_mode = USER_NAMESPACE_FIXED;
+ settings->uid_shift = UID_INVALID;
+ settings->uid_range = UINT32_C(0x10000);
+ } else if (streq(rvalue, "pick")) {
+ /* pick: User namespacing on, UID range is picked randomly */
+ settings->userns_mode = USER_NAMESPACE_PICK;
+ settings->uid_shift = UID_INVALID;
+ settings->uid_range = UINT32_C(0x10000);
+ } else {
+ const char *range, *shift;
+ uid_t sh, rn;
+
+ /* anything else: User namespacing on, UID range is explicitly configured */
+
+ range = strchr(rvalue, ':');
+ if (range) {
+ shift = strndupa(rvalue, range - rvalue);
+ range++;
+
+ r = safe_atou32(range, &rn);
+ if (r < 0 || rn <= 0) {
+ log_syntax(unit, LOG_ERR, filename, line, r, "UID/GID range invalid, ignoring: %s", range);
+ return 0;
+ }
+ } else {
+ shift = rvalue;
+ rn = UINT32_C(0x10000);
+ }
+
+ r = parse_uid(shift, &sh);
+ if (r < 0) {
+ log_syntax(unit, LOG_ERR, filename, line, r, "UID/GID shift invalid, ignoring: %s", range);
+ return 0;
+ }
+
+ settings->userns_mode = USER_NAMESPACE_FIXED;
+ settings->uid_shift = sh;
+ settings->uid_range = rn;
+ }
+
+ return 0;
+}
diff --git a/src/nspawn/nspawn-settings.h b/src/nspawn/nspawn-settings.h
index a017405cd9..e12e91b886 100644
--- a/src/nspawn/nspawn-settings.h
+++ b/src/nspawn/nspawn-settings.h
@@ -33,6 +33,14 @@ typedef enum StartMode {
_START_MODE_INVALID = -1
} StartMode;
+typedef enum UserNamespaceMode {
+ USER_NAMESPACE_NO,
+ USER_NAMESPACE_FIXED,
+ USER_NAMESPACE_PICK,
+ _USER_NAMESPACE_MODE_MAX,
+ _USER_NAMESPACE_MODE_INVALID = -1,
+} UserNamespaceMode;
+
typedef enum SettingsMask {
SETTING_START_MODE = 1 << 0,
SETTING_ENVIRONMENT = 1 << 1,
@@ -47,7 +55,8 @@ typedef enum SettingsMask {
SETTING_VOLATILE_MODE = 1 << 10,
SETTING_CUSTOM_MOUNTS = 1 << 11,
SETTING_WORKING_DIRECTORY = 1 << 12,
- _SETTINGS_MASK_ALL = (1 << 13) -1
+ SETTING_USERNS = 1 << 13,
+ _SETTINGS_MASK_ALL = (1 << 14) -1
} SettingsMask;
typedef struct Settings {
@@ -62,12 +71,15 @@ typedef struct Settings {
unsigned long personality;
sd_id128_t machine_id;
char *working_directory;
+ UserNamespaceMode userns_mode;
+ uid_t uid_shift, uid_range;
/* [Image] */
int read_only;
VolatileMode volatile_mode;
CustomMount *custom_mounts;
unsigned n_custom_mounts;
+ int userns_chown;
/* [Network] */
int private_network;
@@ -99,3 +111,4 @@ int config_parse_tmpfs(const char *unit, const char *filename, unsigned line, co
int config_parse_veth_extra(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_boot(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_pid2(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_private_users(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
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 2024-11-27 12:25:01 +0000