If a user is created with a strictly-speaking invalid name such as '0day' and a
unit created to run as that user, systemd rejects the username and runs the unit
as root.

CVE: CVE-2017-1000082
Upstream-Status: Backport
Signed-off-by: Ross Burton <ross.burton@intel.com>

From e0c4eb1435d50cb3797cf94100d4886dc2022bce Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Thu, 14 Jul 2016 12:23:39 +0200
Subject: [PATCH 1/3] sysusers: move various user credential validity checks to
 src/basic/

This way we can reuse them for validating User=/Group= settings in unit files
(to be added in a later commit).

Also, add some tests for them.
---
 src/basic/user-util.c     | 93 +++++++++++++++++++++++++++++++++++++++++++++++
 src/basic/user-util.h     |  5 +++
 src/sysusers/sysusers.c   | 75 --------------------------------------
 src/test/test-user-util.c | 87 ++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 185 insertions(+), 75 deletions(-)

diff --git a/src/basic/user-util.c b/src/basic/user-util.c
index f65ca3eda..c85b5c6a8 100644
--- a/src/basic/user-util.c
+++ b/src/basic/user-util.c
@@ -29,6 +29,7 @@
 #include <string.h>
 #include <sys/stat.h>
 #include <unistd.h>
+#include <utmp.h>
 
 #include "missing.h"
 #include "alloc-util.h"
@@ -39,6 +40,7 @@
 #include "path-util.h"
 #include "string-util.h"
 #include "user-util.h"
+#include "utf8.h"
 
 bool uid_is_valid(uid_t uid) {
 
@@ -479,3 +481,94 @@ int take_etc_passwd_lock(const char *root) {
 
         return fd;
 }
+
+bool valid_user_group_name(const char *u) {
+        const char *i;
+        long sz;
+
+        /* Checks if the specified name is a valid user/group name. */
+
+        if (isempty(u))
+                return false;
+
+        if (!(u[0] >= 'a' && u[0] <= 'z') &&
+            !(u[0] >= 'A' && u[0] <= 'Z') &&
+            u[0] != '_')
+                return false;
+
+        for (i = u+1; *i; i++) {
+                if (!(*i >= 'a' && *i <= 'z') &&
+                    !(*i >= 'A' && *i <= 'Z') &&
+                    !(*i >= '0' && *i <= '9') &&
+                    *i != '_' &&
+                    *i != '-')
+                        return false;
+        }
+
+        sz = sysconf(_SC_LOGIN_NAME_MAX);
+        assert_se(sz > 0);
+
+        if ((size_t) (i-u) > (size_t) sz)
+                return false;
+
+        if ((size_t) (i-u) > UT_NAMESIZE - 1)
+                return false;
+
+        return true;
+}
+
+bool valid_user_group_name_or_id(const char *u) {
+
+        /* Similar as above, but is also fine with numeric UID/GID specifications, as long as they are in the right
+         * range, and not the invalid user ids. */
+
+        if (isempty(u))
+                return false;
+
+        if (valid_user_group_name(u))
+                return true;
+
+        return parse_uid(u, NULL) >= 0;
+}
+
+bool valid_gecos(const char *d) {
+
+        if (!d)
+                return false;
+
+        if (!utf8_is_valid(d))
+                return false;
+
+        if (string_has_cc(d, NULL))
+                return false;
+
+        /* Colons are used as field separators, and hence not OK */
+        if (strchr(d, ':'))
+                return false;
+
+        return true;
+}
+
+bool valid_home(const char *p) {
+
+        if (isempty(p))
+                return false;
+
+        if (!utf8_is_valid(p))
+                return false;
+
+        if (string_has_cc(p, NULL))
+                return false;
+
+        if (!path_is_absolute(p))
+                return false;
+
+        if (!path_is_safe(p))
+                return false;
+
+        /* Colons are used as field separators, and hence not OK */
+        if (strchr(p, ':'))
+                return false;
+
+        return true;
+}
diff --git a/src/basic/user-util.h b/src/basic/user-util.h
index 8026eca3f..36f71fb00 100644
--- a/src/basic/user-util.h
+++ b/src/basic/user-util.h
@@ -68,3 +68,8 @@ int take_etc_passwd_lock(const char *root);
 static inline bool userns_supported(void) {
         return access("/proc/self/uid_map", F_OK) >= 0;
 }
+
+bool valid_user_group_name(const char *u);
+bool valid_user_group_name_or_id(const char *u);
+bool valid_gecos(const char *d);
+bool valid_home(const char *p);
diff --git a/src/sysusers/sysusers.c b/src/sysusers/sysusers.c
index 4377f1b91..df3b7de30 100644
--- a/src/sysusers/sysusers.c
+++ b/src/sysusers/sysusers.c
@@ -1299,81 +1299,6 @@ static bool item_equal(Item *a, Item *b) {
         return true;
 }
 
-static bool valid_user_group_name(const char *u) {
-        const char *i;
-        long sz;
-
-        if (isempty(u))
-                return false;
-
-        if (!(u[0] >= 'a' && u[0] <= 'z') &&
-            !(u[0] >= 'A' && u[0] <= 'Z') &&
-            u[0] != '_')
-                return false;
-
-        for (i = u+1; *i; i++) {
-                if (!(*i >= 'a' && *i <= 'z') &&
-                    !(*i >= 'A' && *i <= 'Z') &&
-                    !(*i >= '0' && *i <= '9') &&
-                    *i != '_' &&
-                    *i != '-')
-                        return false;
-        }
-
-        sz = sysconf(_SC_LOGIN_NAME_MAX);
-        assert_se(sz > 0);
-
-        if ((size_t) (i-u) > (size_t) sz)
-                return false;
-
-        if ((size_t) (i-u) > UT_NAMESIZE - 1)
-                return false;
-
-        return true;
-}
-
-static bool valid_gecos(const char *d) {
-
-        if (!d)
-                return false;
-
-        if (!utf8_is_valid(d))
-                return false;
-
-        if (string_has_cc(d, NULL))
-                return false;
-
-        /* Colons are used as field separators, and hence not OK */
-        if (strchr(d, ':'))
-                return false;
-
-        return true;
-}
-
-static bool valid_home(const char *p) {
-
-        if (isempty(p))
-                return false;
-
-        if (!utf8_is_valid(p))
-                return false;
-
-        if (string_has_cc(p, NULL))
-                return false;
-
-        if (!path_is_absolute(p))
-                return false;
-
-        if (!path_is_safe(p))
-                return false;
-
-        /* Colons are used as field separators, and hence not OK */
-        if (strchr(p, ':'))
-                return false;
-
-        return true;
-}
-
 static int parse_line(const char *fname, unsigned line, const char *buffer) {
 
         static const Specifier specifier_table[] = {
diff --git a/src/test/test-user-util.c b/src/test/test-user-util.c
index 8d1ec19f1..2a344a9f9 100644
--- a/src/test/test-user-util.c
+++ b/src/test/test-user-util.c
@@ -61,6 +61,88 @@ static void test_uid_ptr(void) {
         assert_se(PTR_TO_UID(UID_TO_PTR(1000)) == 1000);
 }
 
+static void test_valid_user_group_name(void) {
+        assert_se(!valid_user_group_name(NULL));
+        assert_se(!valid_user_group_name(""));
+        assert_se(!valid_user_group_name("1"));
+        assert_se(!valid_user_group_name("65535"));
+        assert_se(!valid_user_group_name("-1"));
+        assert_se(!valid_user_group_name("-kkk"));
+        assert_se(!valid_user_group_name("rööt"));
+        assert_se(!valid_user_group_name("."));
+        assert_se(!valid_user_group_name("eff.eff"));
+        assert_se(!valid_user_group_name("foo\nbar"));
+        assert_se(!valid_user_group_name("0123456789012345678901234567890123456789"));
+        assert_se(!valid_user_group_name_or_id("aaa:bbb"));
+
+        assert_se(valid_user_group_name("root"));
+        assert_se(valid_user_group_name("lennart"));
+        assert_se(valid_user_group_name("LENNART"));
+        assert_se(valid_user_group_name("_kkk"));
+        assert_se(valid_user_group_name("kkk-"));
+        assert_se(valid_user_group_name("kk-k"));
+
+        assert_se(valid_user_group_name("some5"));
+        assert_se(!valid_user_group_name("5some"));
+        assert_se(valid_user_group_name("INNER5NUMBER"));
+}
+
+static void test_valid_user_group_name_or_id(void) {
+        assert_se(!valid_user_group_name_or_id(NULL));
+        assert_se(!valid_user_group_name_or_id(""));
+        assert_se(valid_user_group_name_or_id("0"));
+        assert_se(valid_user_group_name_or_id("1"));
+        assert_se(valid_user_group_name_or_id("65534"));
+        assert_se(!valid_user_group_name_or_id("65535"));
+        assert_se(valid_user_group_name_or_id("65536"));
+        assert_se(!valid_user_group_name_or_id("-1"));
+        assert_se(!valid_user_group_name_or_id("-kkk"));
+        assert_se(!valid_user_group_name_or_id("rööt"));
+        assert_se(!valid_user_group_name_or_id("."));
+        assert_se(!valid_user_group_name_or_id("eff.eff"));
+        assert_se(!valid_user_group_name_or_id("foo\nbar"));
+        assert_se(!valid_user_group_name_or_id("0123456789012345678901234567890123456789"));
+        assert_se(!valid_user_group_name_or_id("aaa:bbb"));
+
+        assert_se(valid_user_group_name_or_id("root"));
+        assert_se(valid_user_group_name_or_id("lennart"));
+        assert_se(valid_user_group_name_or_id("LENNART"));
+        assert_se(valid_user_group_name_or_id("_kkk"));
+        assert_se(valid_user_group_name_or_id("kkk-"));
+        assert_se(valid_user_group_name_or_id("kk-k"));
+
+        assert_se(valid_user_group_name_or_id("some5"));
+        assert_se(!valid_user_group_name_or_id("5some"));
+        assert_se(valid_user_group_name_or_id("INNER5NUMBER"));
+}
+
+static void test_valid_gecos(void) {
+
+        assert_se(!valid_gecos(NULL));
+        assert_se(valid_gecos(""));
+        assert_se(valid_gecos("test"));
+        assert_se(valid_gecos("Ümläüt"));
+        assert_se(!valid_gecos("In\nvalid"));
+        assert_se(!valid_gecos("In:valid"));
+}
+
+static void test_valid_home(void) {
+
+        assert_se(!valid_home(NULL));
+        assert_se(!valid_home(""));
+        assert_se(!valid_home("."));
+        assert_se(!valid_home("/home/.."));
+        assert_se(!valid_home("/home/../"));
+        assert_se(!valid_home("/home\n/foo"));
+        assert_se(!valid_home("./piep"));
+        assert_se(!valid_home("piep"));
+        assert_se(!valid_home("/home/user:lennart"));
+
+        assert_se(valid_home("/"));
+        assert_se(valid_home("/home"));
+        assert_se(valid_home("/home/foo"));
+}
+
 int main(int argc, char*argv[]) {
 
         test_uid_to_name_one(0, "root");
@@ -75,5 +157,10 @@ int main(int argc, char*argv[]) {
         test_parse_uid();
         test_uid_ptr();
 
+        test_valid_user_group_name();
+        test_valid_user_group_name_or_id();
+        test_valid_gecos();
+        test_valid_home();
+
         return 0;
 }
-- 
2.11.0


From 1affacaaf6eff93e53563a644567cc5c3930cb28 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Thu, 14 Jul 2016 12:28:06 +0200
Subject: [PATCH 2/3] core: be stricter when parsing User=/Group= fields

Let's verify the validity of the syntax of the user/group names set.
---
 src/core/load-fragment-gperf.gperf.m4 |  10 +--
 src/core/load-fragment.c              | 118 ++++++++++++++++++++++++++++++++++
 src/core/load-fragment.h              |   2 +
 3 files changed, 125 insertions(+), 5 deletions(-)

diff --git a/src/core/load-fragment-gperf.gperf.m4 b/src/core/load-fragment-gperf.gperf.m4
index 819341898..110089696 100644
--- a/src/core/load-fragment-gperf.gperf.m4
+++ b/src/core/load-fragment-gperf.gperf.m4
@@ -19,9 +19,9 @@ m4_dnl Define the context options only once
 m4_define(`EXEC_CONTEXT_CONFIG_ITEMS',
 `$1.WorkingDirectory,            config_parse_working_directory,     0,                             offsetof($1, exec_context)
 $1.RootDirectory,                config_parse_unit_path_printf,      0,                             offsetof($1, exec_context.root_directory)
-$1.User,                         config_parse_unit_string_printf,    0,                             offsetof($1, exec_context.user)
-$1.Group,                        config_parse_unit_string_printf,    0,                             offsetof($1, exec_context.group)
-$1.SupplementaryGroups,          config_parse_strv,                  0,                             offsetof($1, exec_context.supplementary_groups)
+$1.User,                         config_parse_user_group,            0,                             offsetof($1, exec_context.user)
+$1.Group,                        config_parse_user_group,            0,                             offsetof($1, exec_context.group)
+$1.SupplementaryGroups,          config_parse_user_group_strv,       0,                             offsetof($1, exec_context.supplementary_groups)
 $1.Nice,                         config_parse_exec_nice,             0,                             offsetof($1, exec_context)
 $1.OOMScoreAdjust,               config_parse_exec_oom_score_adjust, 0,                             offsetof($1, exec_context)
 $1.IOSchedulingClass,            config_parse_exec_io_class,         0,                             offsetof($1, exec_context)
@@ -275,8 +275,8 @@ Socket.ExecStartPost,            config_parse_exec,                  SOCKET_EXEC
 Socket.ExecStopPre,              config_parse_exec,                  SOCKET_EXEC_STOP_PRE,          offsetof(Socket, exec_command)
 Socket.ExecStopPost,             config_parse_exec,                  SOCKET_EXEC_STOP_POST,         offsetof(Socket, exec_command)
 Socket.TimeoutSec,               config_parse_sec,                   0,                             offsetof(Socket, timeout_usec)
-Socket.SocketUser,               config_parse_unit_string_printf,    0,                             offsetof(Socket, user)
-Socket.SocketGroup,              config_parse_unit_string_printf,    0,                             offsetof(Socket, group)
+Socket.SocketUser,               config_parse_user_group,            0,                             offsetof(Socket, user)
+Socket.SocketGroup,              config_parse_user_group,            0,                             offsetof(Socket, group)
 Socket.SocketMode,               config_parse_mode,                  0,                             offsetof(Socket, socket_mode)
 Socket.DirectoryMode,            config_parse_mode,                  0,                             offsetof(Socket, directory_mode)
 Socket.Accept,                   config_parse_bool,                  0,                             offsetof(Socket, accept)
diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
index 86b4fb071..f43781803 100644
--- a/src/core/load-fragment.c
+++ b/src/core/load-fragment.c
@@ -64,6 +64,7 @@
 #include "unit-name.h"
 #include "unit-printf.h"
 #include "unit.h"
+#include "user-util.h"
 #include "utf8.h"
 #include "web-util.h"
 
@@ -1758,6 +1759,123 @@ int config_parse_sec_fix_0(
         return 0;
 }
 
+int config_parse_user_group(
+                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) {
+
+        char **user = data, *n;
+        Unit *u = userdata;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(u);
+
+        if (isempty(rvalue))
+                n = NULL;
+        else {
+                _cleanup_free_ char *k = NULL;
+
+                r = unit_full_printf(u, rvalue, &k);
+                if (r < 0) {
+                        log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve unit specifiers in %s, ignoring: %m", rvalue);
+                        return 0;
+                }
+
+                if (!valid_user_group_name_or_id(k)) {
+                        log_syntax(unit, LOG_ERR, filename, line, 0, "Invalid user/group name or numeric ID, ignoring: %s", k);
+                        return 0;
+                }
+
+                n = k;
+                k = NULL;
+        }
+
+        free(*user);
+        *user = n;
+
+        return 0;
+}
+
+int config_parse_user_group_strv(
+                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) {
+
+        char ***users = data;
+        Unit *u = userdata;
+        const char *p;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(u);
+
+        if (isempty(rvalue)) {
+                char **empty;
+
+                empty = new0(char*, 1);
+                if (!empty)
+                        return log_oom();
+
+                strv_free(*users);
+                *users = empty;
+
+                return 0;
+        }
+
+        p = rvalue;
+        for (;;) {
+                _cleanup_free_ char *word = NULL, *k = NULL;
+
+                r = extract_first_word(&p, &word, WHITESPACE, 0);
+                if (r == 0)
+                        break;
+                if (r == -ENOMEM)
+                        return log_oom();
+                if (r < 0) {
+                        log_syntax(unit, LOG_ERR, filename, line, r, "Invalid syntax, ignoring: %s", rvalue);
+                        break;
+                }
+
+                r = unit_full_printf(u, word, &k);
+                if (r < 0) {
+                        log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve unit specifiers in %s, ignoring: %m", word);
+                        continue;
+                }
+
+                if (!valid_user_group_name_or_id(k)) {
+                        log_syntax(unit, LOG_ERR, filename, line, 0, "Invalid user/group name or numeric ID, ignoring: %s", k);
+                        continue;
+                }
+
+                r = strv_push(users, k);
+                if (r < 0)
+                        return log_oom();
+
+                k = NULL;
+        }
+
+        return 0;
+}
+
 int config_parse_busname_service(
                 const char *unit,
                 const char *filename,
diff --git a/src/core/load-fragment.h b/src/core/load-fragment.h
index b36a2e3a0..213bce55a 100644
--- a/src/core/load-fragment.h
+++ b/src/core/load-fragment.h
@@ -111,6 +111,8 @@ int config_parse_exec_utmp_mode(const char *unit, const char *filename, unsigned
 int config_parse_working_directory(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_fdname(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_sec_fix_0(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_user_group(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_user_group_strv(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);
 
 /* gperf prototypes */
 const struct ConfigPerfItem* load_fragment_gperf_lookup(const char *key, unsigned length);
-- 
2.11.0


From 97e0456384ed5c930394062d340237ea6130ece0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Thu, 6 Jul 2017 13:28:19 -0400
Subject: [PATCH 3/3] core/load-fragment: refuse units with errors in certain
 directives

If an error is encountered in any of the Exec* lines, WorkingDirectory,
SELinuxContext, ApparmorProfile, SmackProcessLabel, Service (in .socket
units), User, or Group, refuse to load the unit. If the config stanza
has support, ignore the failure if '-' is present.

For those configuration directives, even if we started the unit, it's
pretty likely that it'll do something unexpected (like write files
in a wrong place, or with a wrong context, or run with wrong permissions,
etc). It seems better to refuse to start the unit and have the admin
clean up the configuration without giving the service a chance to mess
up stuff.

Note that all "security" options that restrict what the unit can do
(Capabilities, AmbientCapabilities, Restrict*, SystemCallFilter, Limit*,
PrivateDevices, Protect*, etc) are _not_ treated like this. Such options are
only supplementary, and are not always available depending on the architecture
and compilation options, so unit authors have to make sure that the service
runs correctly without them anyway.

Fixes #6237, #6277.

Signed-off-by: Ross Burton <ross.burton@intel.com>
---
 src/core/load-fragment.c  | 101 ++++++++++++++++++++++++++++------------------
 src/test/test-unit-file.c |  14 +++----
 2 files changed, 69 insertions(+), 46 deletions(-)

diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
index f43781803..b1fb1d407 100644
--- a/src/core/load-fragment.c
+++ b/src/core/load-fragment.c
@@ -626,20 +626,28 @@ int config_parse_exec(
 
                 if (isempty(f)) {
                         /* First word is either "-" or "@" with no command. */
-                        log_syntax(unit, LOG_ERR, filename, line, 0, "Empty path in command line, ignoring: \"%s\"", rvalue);
-                        return 0;
+                        log_syntax(unit, LOG_ERR, filename, line, 0,
+                                   "Empty path in command line%s: \"%s\"",
+                                   ignore ? ", ignoring" : "", rvalue);
+                        return ignore ? 0 : -ENOEXEC;
                 }
                 if (!string_is_safe(f)) {
-                        log_syntax(unit, LOG_ERR, filename, line, 0, "Executable path contains special characters, ignoring: %s", rvalue);
-                        return 0;
+                        log_syntax(unit, LOG_ERR, filename, line, 0,
+                                   "Executable path contains special characters%s: %s",
+                                   ignore ? ", ignoring" : "", rvalue);
+                        return ignore ? 0 : -ENOEXEC;
                 }
                 if (!path_is_absolute(f)) {
-                        log_syntax(unit, LOG_ERR, filename, line, 0, "Executable path is not absolute, ignoring: %s", rvalue);
-                        return 0;
+                        log_syntax(unit, LOG_ERR, filename, line, 0,
+                                   "Executable path is not absolute%s: %s",
+                                   ignore ? ", ignoring" : "", rvalue);
+                        return ignore ? 0 : -ENOEXEC;
                 }
                 if (endswith(f, "/")) {
-                        log_syntax(unit, LOG_ERR, filename, line, 0, "Executable path specifies a directory, ignoring: %s", rvalue);
-                        return 0;
+                        log_syntax(unit, LOG_ERR, filename, line, 0,
+                                   "Executable path specifies a directory%s: %s",
+                                   ignore ? ", ignoring" : "", rvalue);
+                        return ignore ? 0 : -ENOEXEC;
                 }
 
                 if (f == firstword) {
@@ -695,7 +703,7 @@ int config_parse_exec(
                         if (r == 0)
                                 break;
                         else if (r < 0)
-                                return 0;
+                                return ignore ? 0 : -ENOEXEC;
 
                         if (!GREEDY_REALLOC(n, nbufsize, nlen + 2))
                                 return log_oom();
@@ -705,8 +713,10 @@ int config_parse_exec(
                 }
 
                 if (!n || !n[0]) {
-                        log_syntax(unit, LOG_ERR, filename, line, 0, "Empty executable name or zeroeth argument, ignoring: %s", rvalue);
-                        return 0;
+                        log_syntax(unit, LOG_ERR, filename, line, 0,
+                                   "Empty executable name or zeroeth argument%s: %s",
+                                   ignore ? ", ignoring" : "", rvalue);
+                        return ignore ? 0 : -ENOEXEC;
                 }
 
                 nce = new0(ExecCommand, 1);
@@ -1214,8 +1224,10 @@ int config_parse_exec_selinux_context(
 
         r = unit_name_printf(u, rvalue, &k);
         if (r < 0) {
-                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve specifiers, ignoring: %m");
-                return 0;
+                log_syntax(unit, LOG_ERR, filename, line, r,
+                           "Failed to resolve specifiers%s: %m",
+                           ignore ? ", ignoring" : "");
+                return ignore ? 0 : -ENOEXEC;
         }
 
         free(c->selinux_context);
@@ -1262,8 +1274,10 @@ int config_parse_exec_apparmor_profile(
 
         r = unit_name_printf(u, rvalue, &k);
         if (r < 0) {
-                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve specifiers, ignoring: %m");
-                return 0;
+                log_syntax(unit, LOG_ERR, filename, line, r,
+                           "Failed to resolve specifiers%s: %m",
+                           ignore ? ", ignoring" : "");
+                return ignore ? 0 : -ENOEXEC;
         }
 
         free(c->apparmor_profile);
@@ -1310,8 +1324,10 @@ int config_parse_exec_smack_process_label(
 
         r = unit_name_printf(u, rvalue, &k);
         if (r < 0) {
-                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve specifiers, ignoring: %m");
-                return 0;
+                log_syntax(unit, LOG_ERR, filename, line, r,
+                           "Failed to resolve specifiers%s: %m",
+                           ignore ? ", ignoring" : "");
+                return ignore ? 0 : -ENOEXEC;
         }
 
         free(c->smack_process_label);
@@ -1520,19 +1536,19 @@ int config_parse_socket_service(
 
         r = unit_name_printf(UNIT(s), rvalue, &p);
         if (r < 0) {
-                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve specifiers, ignoring: %s", rvalue);
-                return 0;
+                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve specifiers: %s", rvalue);
+                return -ENOEXEC;
         }
 
         if (!endswith(p, ".service")) {
-                log_syntax(unit, LOG_ERR, filename, line, 0, "Unit must be of type service, ignoring: %s", rvalue);
-                return 0;
+                log_syntax(unit, LOG_ERR, filename, line, 0, "Unit must be of type service: %s", rvalue);
+                return -ENOEXEC;
         }
 
         r = manager_load_unit(UNIT(s)->manager, p, NULL, &error, &x);
         if (r < 0) {
-                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to load unit %s, ignoring: %s", rvalue, bus_error_message(&error, r));
-                return 0;
+                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to load unit %s: %s", rvalue, bus_error_message(&error, r));
+                return -ENOEXEC;
         }
 
         unit_ref_set(&s->service, x);
@@ -1787,13 +1803,13 @@ int config_parse_user_group(
 
                 r = unit_full_printf(u, rvalue, &k);
                 if (r < 0) {
-                        log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve unit specifiers in %s, ignoring: %m", rvalue);
-                        return 0;
+                        log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve unit specifiers in %s: %m", rvalue);
+                        return -ENOEXEC;
                 }
 
                 if (!valid_user_group_name_or_id(k)) {
-                        log_syntax(unit, LOG_ERR, filename, line, 0, "Invalid user/group name or numeric ID, ignoring: %s", k);
-                        return 0;
+                        log_syntax(unit, LOG_ERR, filename, line, 0, "Invalid user/group name or numeric ID: %s", k);
+                        return -ENOEXEC;
                 }
 
                 n = k;
@@ -1851,19 +1867,19 @@ int config_parse_user_group_strv(
                 if (r == -ENOMEM)
                         return log_oom();
                 if (r < 0) {
-                        log_syntax(unit, LOG_ERR, filename, line, r, "Invalid syntax, ignoring: %s", rvalue);
-                        break;
+                        log_syntax(unit, LOG_ERR, filename, line, r, "Invalid syntax: %s", rvalue);
+                        return -ENOEXEC;
                 }
 
                 r = unit_full_printf(u, word, &k);
                 if (r < 0) {
-                        log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve unit specifiers in %s, ignoring: %m", word);
-                        continue;
+                        log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve unit specifiers in %s: %m", word);
+                        return -ENOEXEC;
                 }
 
                 if (!valid_user_group_name_or_id(k)) {
-                        log_syntax(unit, LOG_ERR, filename, line, 0, "Invalid user/group name or numeric ID, ignoring: %s", k);
-                        continue;
+                        log_syntax(unit, LOG_ERR, filename, line, 0, "Invalid user/group name or numeric ID: %s", k);
+                        return -ENOEXEC;
                 }
 
                 r = strv_push(users, k);
@@ -2022,20 +2038,24 @@ int config_parse_working_directory(
 
                 r = unit_full_printf(u, rvalue, &k);
                 if (r < 0) {
-                        log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve unit specifiers in working directory path '%s', ignoring: %m", rvalue);
-                        return 0;
+                        log_syntax(unit, LOG_ERR, filename, line, r,
+                                   "Failed to resolve unit specifiers in working directory path '%s'%s: %m",
+                                   rvalue, missing_ok ? ", ignoring" : "");
+                        return missing_ok ? 0 : -ENOEXEC;
                 }
 
                 path_kill_slashes(k);
 
                 if (!utf8_is_valid(k)) {
                         log_syntax_invalid_utf8(unit, LOG_ERR, filename, line, rvalue);
-                        return 0;
+                        return missing_ok ? 0 : -ENOEXEC;
                 }
 
                 if (!path_is_absolute(k)) {
-                        log_syntax(unit, LOG_ERR, filename, line, 0, "Working directory path '%s' is not absolute, ignoring.", rvalue);
-                        return 0;
+                        log_syntax(unit, LOG_ERR, filename, line, 0,
+                                   "Working directory path '%s' is not absolute%s.",
+                                   rvalue, missing_ok ? ", ignoring" : "");
+                        return missing_ok ? 0 : -ENOEXEC;
                 }
 
                 free(c->working_directory);
@@ -4043,8 +4063,11 @@ int unit_load_fragment(Unit *u) {
                         return r;
 
                 r = load_from_path(u, k);
-                if (r < 0)
+                if (r < 0) {
+                        if (r == -ENOEXEC)
+                                log_unit_notice(u, "Unit configuration has fatal error, unit will not be started.");
                         return r;
+                }
 
                 if (u->load_state == UNIT_STUB) {
                         SET_FOREACH(t, u->names, i) {
diff --git a/src/test/test-unit-file.c b/src/test/test-unit-file.c
index ade0ff2a6..fe1969570 100644
--- a/src/test/test-unit-file.c
+++ b/src/test/test-unit-file.c
@@ -146,7 +146,7 @@ static void test_config_parse_exec(void) {
         r = config_parse_exec(NULL, "fake", 4, "section", 1,
                               "LValue", 0, "/RValue/ argv0 r1",
                               &c, u);
-        assert_se(r == 0);
+        assert_se(r == -ENOEXEC);
         assert_se(c1->command_next == NULL);
 
         log_info("/* honour_argv0 */");
@@ -161,7 +161,7 @@ static void test_config_parse_exec(void) {
         r = config_parse_exec(NULL, "fake", 3, "section", 1,
                               "LValue", 0, "@/RValue",
                               &c, u);
-        assert_se(r == 0);
+        assert_se(r == -ENOEXEC);
         assert_se(c1->command_next == NULL);
 
         log_info("/* no command, whitespace only, reset */");
@@ -220,7 +220,7 @@ static void test_config_parse_exec(void) {
                               "-@/RValue argv0 r1 ; ; "
                               "/goo/goo boo",
                               &c, u);
-        assert_se(r >= 0);
+        assert_se(r == -ENOEXEC);
         c1 = c1->command_next;
         check_execcommand(c1, "/RValue", "argv0", "r1", NULL, true);
 
@@ -374,7 +374,7 @@ static void test_config_parse_exec(void) {
                 r = config_parse_exec(NULL, "fake", 4, "section", 1,
                                       "LValue", 0, path,
                                       &c, u);
-                assert_se(r == 0);
+                assert_se(r == -ENOEXEC);
                 assert_se(c1->command_next == NULL);
         }
 
@@ -401,21 +401,21 @@ static void test_config_parse_exec(void) {
         r = config_parse_exec(NULL, "fake", 4, "section", 1,
                               "LValue", 0, "/path\\",
                               &c, u);
-        assert_se(r == 0);
+        assert_se(r == -ENOEXEC);
         assert_se(c1->command_next == NULL);
 
         log_info("/* missing ending ' */");
         r = config_parse_exec(NULL, "fake", 4, "section", 1,
                               "LValue", 0, "/path 'foo",
                               &c, u);
-        assert_se(r == 0);
+        assert_se(r == -ENOEXEC);
         assert_se(c1->command_next == NULL);
 
         log_info("/* missing ending ' with trailing backslash */");
         r = config_parse_exec(NULL, "fake", 4, "section", 1,
                               "LValue", 0, "/path 'foo\\",
                               &c, u);
-        assert_se(r == 0);
+        assert_se(r == -ENOEXEC);
         assert_se(c1->command_next == NULL);
 
         log_info("/* invalid space between modifiers */");
-- 
2.11.0