Reject invalid quoted strings

String which ended in an unfinished quote were accepted, potentially
with bad memory accesses.

Reject anything which ends in a unfished quote, or contains
non-whitespace characters right after the closing quote.

_FOREACH_WORD now returns the invalid character in *state. But this return
value is not checked anywhere yet.

Also, make 'word' and 'state' variables const pointers, and rename 'w'
to 'word' in various places. Things are easier to read if the same name
is used consistently.

mbiebl_> am I correct that something like this doesn't work
mbiebl_> ExecStart=/usr/bin/encfs --extpass='/bin/systemd-ask-passwd "Unlock EncFS"'
mbiebl_> systemd seems to strip of the quotes
mbiebl_> systemctl status shows
mbiebl_> ExecStart=/usr/bin/encfs --extpass='/bin/systemd-ask-password Unlock EncFS  $RootDir $MountPoint
mbiebl_> which is pretty weird

3 files changed, 80 insertions, 84 deletions

diff --git a/src/core/device.c b/src/core/device.c
index 444286e02b..2c41c7b6f4 100644
--- a/src/core/device.c
+++ b/src/core/device.c
@@ -220,7 +220,7 @@ static int device_make_description(Unit *u, struct udev_device *dev, const char
 
 static int device_add_udev_wants(Unit *u, struct udev_device *dev) {
         const char *wants;
-        char *state, *w;
+        const char *word, *state;
         size_t l;
         int r;
 
@@ -234,11 +234,11 @@ static int device_add_udev_wants(Unit *u, struct udev_device *dev) {
         if (!wants)
                 return 0;
 
-        FOREACH_WORD_QUOTED(w, l, wants, state) {
+        FOREACH_WORD_QUOTED(word, l, wants, state) {
                 _cleanup_free_ char *n = NULL;
                 char e[l+1];
 
-                memcpy(e, w, l);
+                memcpy(e, word, l);
                 e[l] = 0;
 
                 n = unit_name_mangle(e, MANGLE_NOGLOB);
@@ -393,13 +393,13 @@ static int device_process_new_device(Manager *m, struct udev_device *dev) {
          * aliases */
         alias = udev_device_get_property_value(dev, "SYSTEMD_ALIAS");
         if (alias) {
-                char *state, *w;
+                const char *word, *state;
                 size_t l;
 
-                FOREACH_WORD_QUOTED(w, l, alias, state) {
+                FOREACH_WORD_QUOTED(word, l, alias, state) {
                         char e[l+1];
 
-                        memcpy(e, w, l);
+                        memcpy(e, word, l);
                         e[l] = 0;
 
                         if (path_is_absolute(e))
diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
index 6d8431015d..b0448e2c4b 100644
--- a/src/core/load-fragment.c
+++ b/src/core/load-fragment.c
@@ -97,18 +97,18 @@ int config_parse_unit_deps(const char* unit,
 
         UnitDependency d = ltype;
         Unit *u = userdata;
-        char *w, *state;
+        const char *word, *state;
         size_t l;
 
         assert(filename);
         assert(lvalue);
         assert(rvalue);
 
-        FOREACH_WORD_QUOTED(w, l, rvalue, state) {
+        FOREACH_WORD_QUOTED(word, l, rvalue, state) {
                 _cleanup_free_ char *t = NULL, *k = NULL;
                 int r;
 
-                t = strndup(w, l);
+                t = strndup(word, l);
                 if (!t)
                         return log_oom();
 
@@ -227,7 +227,8 @@ int config_parse_unit_path_strv_printf(
                 void *data,
                 void *userdata) {
 
-        char *w, *state, ***x = data;
+        char ***x = data;
+        const char *word, *state;
         Unit *u = userdata;
         size_t l;
         int r;
@@ -237,11 +238,11 @@ int config_parse_unit_path_strv_printf(
         assert(rvalue);
         assert(u);
 
-        FOREACH_WORD_QUOTED(w, l, rvalue, state) {
+        FOREACH_WORD_QUOTED(word, l, rvalue, state) {
                 _cleanup_free_ char *k = NULL;
                 char t[l+1];
 
-                memcpy(t, w, l);
+                memcpy(t, word, l);
                 t[l] = 0;
 
                 r = unit_full_printf(u, t, &k);
@@ -533,9 +534,8 @@ int config_parse_exec(const char *unit,
          * overriding of argv[0]. */
         for (;;) {
                 int i;
-                char *w;
+                const char *word, *state;
                 size_t l;
-                char *state;
                 bool honour_argv0 = false, ignore = false;
 
                 path = NULL;
@@ -566,8 +566,8 @@ int config_parse_exec(const char *unit,
                 }
 
                 k = 0;
-                FOREACH_WORD_QUOTED(w, l, rvalue, state) {
-                        if (strneq(w, ";", MAX(l, 1U)))
+                FOREACH_WORD_QUOTED(word, l, rvalue, state) {
+                        if (strneq(word, ";", MAX(l, 1U)))
                                 break;
 
                         k++;
@@ -578,16 +578,16 @@ int config_parse_exec(const char *unit,
                         return log_oom();
 
                 k = 0;
-                FOREACH_WORD_QUOTED(w, l, rvalue, state) {
-                        if (strneq(w, ";", MAX(l, 1U)))
+                FOREACH_WORD_QUOTED(word, l, rvalue, state) {
+                        if (strneq(word, ";", MAX(l, 1U)))
                                 break;
-                        else if (strneq(w, "\\;", MAX(l, 1U)))
-                                w ++;
+                        else if (strneq(word, "\\;", MAX(l, 1U)))
+                                word ++;
 
-                        if (honour_argv0 && w == rvalue) {
+                        if (honour_argv0 && word == rvalue) {
                                 assert(!path);
 
-                                path = strndup(w, l);
+                                path = strndup(word, l);
                                 if (!path) {
                                         r = log_oom();
                                         goto fail;
@@ -602,7 +602,7 @@ int config_parse_exec(const char *unit,
                         } else {
                                 char *c;
 
-                                c = n[k++] = cunescape_length(w, l);
+                                c = n[k++] = cunescape_length(word, l);
                                 if (!c) {
                                         r = log_oom();
                                         goto fail;
@@ -854,9 +854,8 @@ int config_parse_exec_cpu_affinity(const char *unit,
                                    void *userdata) {
 
         ExecContext *c = data;
-        char *w;
+        const char *word, *state;
         size_t l;
-        char *state;
 
         assert(filename);
         assert(lvalue);
@@ -871,12 +870,12 @@ int config_parse_exec_cpu_affinity(const char *unit,
                 return 0;
         }
 
-        FOREACH_WORD_QUOTED(w, l, rvalue, state) {
+        FOREACH_WORD_QUOTED(word, l, rvalue, state) {
                 _cleanup_free_ char *t = NULL;
                 int r;
                 unsigned cpu;
 
-                t = strndup(w, l);
+                t = strndup(word, l);
                 if (!t)
                         return log_oom();
 
@@ -945,9 +944,8 @@ int config_parse_exec_secure_bits(const char *unit,
                                   void *userdata) {
 
         ExecContext *c = data;
-        char *w;
         size_t l;
-        char *state;
+        const char *word, *state;
 
         assert(filename);
         assert(lvalue);
@@ -960,18 +958,18 @@ int config_parse_exec_secure_bits(const char *unit,
                 return 0;
         }
 
-        FOREACH_WORD_QUOTED(w, l, rvalue, state) {
-                if (first_word(w, "keep-caps"))
+        FOREACH_WORD_QUOTED(word, l, rvalue, state) {
+                if (first_word(word, "keep-caps"))
                         c->secure_bits |= 1<<SECURE_KEEP_CAPS;
-                else if (first_word(w, "keep-caps-locked"))
+                else if (first_word(word, "keep-caps-locked"))
                         c->secure_bits |= 1<<SECURE_KEEP_CAPS_LOCKED;
-                else if (first_word(w, "no-setuid-fixup"))
+                else if (first_word(word, "no-setuid-fixup"))
                         c->secure_bits |= 1<<SECURE_NO_SETUID_FIXUP;
-                else if (first_word(w, "no-setuid-fixup-locked"))
+                else if (first_word(word, "no-setuid-fixup-locked"))
                         c->secure_bits |= 1<<SECURE_NO_SETUID_FIXUP_LOCKED;
-                else if (first_word(w, "noroot"))
+                else if (first_word(word, "noroot"))
                         c->secure_bits |= 1<<SECURE_NOROOT;
-                else if (first_word(w, "noroot-locked"))
+                else if (first_word(word, "noroot-locked"))
                         c->secure_bits |= 1<<SECURE_NOROOT_LOCKED;
                 else {
                         log_syntax(unit, LOG_ERR, filename, line, EINVAL,
@@ -995,9 +993,8 @@ int config_parse_bounding_set(const char *unit,
                               void *userdata) {
 
         uint64_t *capability_bounding_set_drop = data;
-        char *w;
+        const char *word, *state;
         size_t l;
-        char *state;
         bool invert = false;
         uint64_t sum = 0;
 
@@ -1016,12 +1013,12 @@ int config_parse_bounding_set(const char *unit,
          * non-inverted everywhere to have a fully normalized
          * interface. */
 
-        FOREACH_WORD_QUOTED(w, l, rvalue, state) {
+        FOREACH_WORD_QUOTED(word, l, rvalue, state) {
                 _cleanup_free_ char *t = NULL;
                 int r;
                 cap_value_t cap;
 
-                t = strndup(w, l);
+                t = strndup(word, l);
                 if (!t)
                         return log_oom();
 
@@ -1163,9 +1160,8 @@ int config_parse_exec_mount_flags(const char *unit,
                                   void *userdata) {
 
         ExecContext *c = data;
-        char *w;
+        const char *word, *state;
         size_t l;
-        char *state;
         unsigned long flags = 0;
 
         assert(filename);
@@ -1173,10 +1169,10 @@ int config_parse_exec_mount_flags(const char *unit,
         assert(rvalue);
         assert(data);
 
-        FOREACH_WORD_SEPARATOR(w, l, rvalue, ", ", state) {
+        FOREACH_WORD_SEPARATOR(word, l, rvalue, ", ", state) {
                 _cleanup_free_ char *t;
 
-                t = strndup(w, l);
+                t = strndup(word, l);
                 if (!t)
                         return log_oom();
 
@@ -1184,7 +1180,7 @@ int config_parse_exec_mount_flags(const char *unit,
                         flags = MS_SHARED;
                 else if (streq(t, "slave"))
                         flags = MS_SLAVE;
-                else if (streq(w, "private"))
+                else if (streq(word, "private"))
                         flags = MS_PRIVATE;
                 else {
                         log_syntax(unit, LOG_ERR, filename, line, EINVAL, "Failed to parse mount flag %s, ignoring: %s", t, rvalue);
@@ -1538,7 +1534,7 @@ int config_parse_service_sockets(const char *unit,
 
         Service *s = data;
         int r;
-        char *state, *w;
+        const char *word, *state;
         size_t l;
 
         assert(filename);
@@ -1546,10 +1542,10 @@ int config_parse_service_sockets(const char *unit,
         assert(rvalue);
         assert(data);
 
-        FOREACH_WORD_QUOTED(w, l, rvalue, state) {
+        FOREACH_WORD_QUOTED(word, l, rvalue, state) {
                 _cleanup_free_ char *t = NULL, *k = NULL;
 
-                t = strndup(w, l);
+                t = strndup(word, l);
                 if (!t)
                         return log_oom();
 
@@ -1780,7 +1776,8 @@ int config_parse_environ(const char *unit,
                          void *userdata) {
 
         Unit *u = userdata;
-        char*** env = data, *w, *state;
+        char*** env = data;
+        const char *word, *state;
         size_t l;
         _cleanup_free_ char *k = NULL;
         int r;
@@ -1809,11 +1806,11 @@ int config_parse_environ(const char *unit,
         if (!k)
                 return log_oom();
 
-        FOREACH_WORD_QUOTED(w, l, k, state) {
+        FOREACH_WORD_QUOTED(word, l, k, state) {
                 _cleanup_free_ char *n;
                 char **x;
 
-                n = cunescape_length(w, l);
+                n = cunescape_length(word, l);
                 if (!n)
                         return log_oom();
 
@@ -2052,20 +2049,19 @@ int config_parse_unit_requires_mounts_for(
                 void *userdata) {
 
         Unit *u = userdata;
-        char *state;
+        const char *word, *state;
         size_t l;
-        char *w;
 
         assert(filename);
         assert(lvalue);
         assert(rvalue);
         assert(data);
 
-        FOREACH_WORD_QUOTED(w, l, rvalue, state) {
+        FOREACH_WORD_QUOTED(word, l, rvalue, state) {
                 int r;
                 _cleanup_free_ char *n;
 
-                n = strndup(w, l);
+                n = strndup(word, l);
                 if (!n)
                         return log_oom();
 
@@ -2156,7 +2152,7 @@ int config_parse_syscall_filter(
         ExecContext *c = data;
         Unit *u = userdata;
         bool invert = false;
-        char *w, *state;
+        const char *word, *state;
         size_t l;
         int r;
 
@@ -2209,11 +2205,11 @@ int config_parse_syscall_filter(
                 }
         }
 
-        FOREACH_WORD_QUOTED(w, l, rvalue, state) {
+        FOREACH_WORD_QUOTED(word, l, rvalue, state) {
                 _cleanup_free_ char *t = NULL;
                 int id;
 
-                t = strndup(w, l);
+                t = strndup(word, l);
                 if (!t)
                         return log_oom();
 
@@ -2257,7 +2253,7 @@ int config_parse_syscall_archs(
                 void *userdata) {
 
         Set **archs = data;
-        char *w, *state;
+        const char *word, *state;
         size_t l;
         int r;
 
@@ -2271,11 +2267,11 @@ int config_parse_syscall_archs(
         if (r < 0)
                 return log_oom();
 
-        FOREACH_WORD_QUOTED(w, l, rvalue, state) {
+        FOREACH_WORD_QUOTED(word, l, rvalue, state) {
                 _cleanup_free_ char *t = NULL;
                 uint32_t a;
 
-                t = strndup(w, l);
+                t = strndup(word, l);
                 if (!t)
                         return log_oom();
 
@@ -2345,7 +2341,7 @@ int config_parse_address_families(
         ExecContext *c = data;
         Unit *u = userdata;
         bool invert = false;
-        char *w, *state;
+        const char *word, *state;
         size_t l;
         int r;
 
@@ -2375,11 +2371,11 @@ int config_parse_address_families(
                 c->address_families_whitelist = !invert;
         }
 
-        FOREACH_WORD_QUOTED(w, l, rvalue, state) {
+        FOREACH_WORD_QUOTED(word, l, rvalue, state) {
                 _cleanup_free_ char *t = NULL;
                 int af;
 
-                t = strndup(w, l);
+                t = strndup(word, l);
                 if (!t)
                         return log_oom();
 
@@ -2874,7 +2870,8 @@ int config_parse_runtime_directory(
                 void *data,
                 void *userdata) {
 
-        char***rt = data, *w, *state;
+        char***rt = data;
+        const char *word, *state;
         size_t l;
         int r;
 
@@ -2890,10 +2887,10 @@ int config_parse_runtime_directory(
                 return 0;
         }
 
-        FOREACH_WORD_QUOTED(w, l, rvalue, state) {
+        FOREACH_WORD_QUOTED(word, l, rvalue, state) {
                 _cleanup_free_ char *n;
 
-                n = strndup(w, l);
+                n = strndup(word, l);
                 if (!n)
                         return log_oom();
 
@@ -2924,9 +2921,8 @@ int config_parse_set_status(
                 void *data,
                 void *userdata) {
 
-        char *w;
         size_t l;
-        char *state;
+        const char *word, *state;
         int r;
         ExitStatusSet *status_set = data;
 
@@ -2941,11 +2937,11 @@ int config_parse_set_status(
                 return 0;
         }
 
-        FOREACH_WORD(w, l, rvalue, state) {
+        FOREACH_WORD(word, l, rvalue, state) {
                 _cleanup_free_ char *temp;
                 int val;
 
-                temp = strndup(w, l);
+                temp = strndup(word, l);
                 if (!temp)
                         return log_oom();
 
@@ -2960,11 +2956,11 @@ int config_parse_set_status(
 
                                 r = set_put(status_set->signal, INT_TO_PTR(val));
                                 if (r < 0) {
-                                        log_syntax(unit, LOG_ERR, filename, line, -r, "Unable to store: %s", w);
+                                        log_syntax(unit, LOG_ERR, filename, line, -r, "Unable to store: %s", word);
                                         return r;
                                 }
                         } else {
-                                log_syntax(unit, LOG_ERR, filename, line, -val, "Failed to parse value, ignoring: %s", w);
+                                log_syntax(unit, LOG_ERR, filename, line, -val, "Failed to parse value, ignoring: %s", word);
                                 return 0;
                         }
                 } else {
@@ -2977,7 +2973,7 @@ int config_parse_set_status(
 
                                 r = set_put(status_set->status, INT_TO_PTR(val));
                                 if (r < 0) {
-                                        log_syntax(unit, LOG_ERR, filename, line, -r, "Unable to store: %s", w);
+                                        log_syntax(unit, LOG_ERR, filename, line, -r, "Unable to store: %s", word);
                                         return r;
                                 }
                         }
@@ -2999,7 +2995,8 @@ int config_parse_namespace_path_strv(
                 void *data,
                 void *userdata) {
 
-        char*** sv = data, *w, *state;
+        char*** sv = data;
+        const char *word, *state;
         size_t l;
         int r;
 
@@ -3015,11 +3012,11 @@ int config_parse_namespace_path_strv(
                 return 0;
         }
 
-        FOREACH_WORD_QUOTED(w, l, rvalue, state) {
+        FOREACH_WORD_QUOTED(word, l, rvalue, state) {
                 _cleanup_free_ char *n;
                 int offset;
 
-                n = strndup(w, l);
+                n = strndup(word, l);
                 if (!n)
                         return log_oom();
 
diff --git a/src/core/main.c b/src/core/main.c
index 2741989c48..fad15c7c3f 100644
--- a/src/core/main.c
+++ b/src/core/main.c
@@ -455,9 +455,8 @@ static int config_parse_cpu_affinity2(
                 void *data,
                 void *userdata) {
 
-        char *w;
+        const char *word, *state;
         size_t l;
-        char *state;
         cpu_set_t *c = NULL;
         unsigned ncpus = 0;
 
@@ -465,12 +464,12 @@ static int config_parse_cpu_affinity2(
         assert(lvalue);
         assert(rvalue);
 
-        FOREACH_WORD_QUOTED(w, l, rvalue, state) {
+        FOREACH_WORD_QUOTED(word, l, rvalue, state) {
                 char *t;
                 int r;
                 unsigned cpu;
 
-                if (!(t = strndup(w, l)))
+                if (!(t = strndup(word, l)))
                         return log_oom();
 
                 r = safe_atou(t, &cpu);
@@ -559,7 +558,7 @@ static int config_parse_join_controllers(const char *unit,
                                          void *userdata) {
 
         unsigned n = 0;
-        char *state, *w;
+        const char *word, *state;
         size_t length;
 
         assert(filename);
@@ -568,10 +567,10 @@ static int config_parse_join_controllers(const char *unit,
 
         free_join_controllers();
 
-        FOREACH_WORD_QUOTED(w, length, rvalue, state) {
+        FOREACH_WORD_QUOTED(word, length, rvalue, state) {
                 char *s, **l;
 
-                s = strndup(w, length);
+                s = strndup(word, length);
                 if (!s)
                         return log_oom();