diff options
| -rw-r--r-- | src/nspawn/nspawn-gperf.gperf | 4 | ||||
| -rw-r--r-- | src/nspawn/nspawn-settings.c | 86 | ||||
| -rw-r--r-- | src/nspawn/nspawn-settings.h | 15 | ||||
| -rw-r--r-- | src/nspawn/nspawn.c | 183 |
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; |