diff --git a/src/basic/path-util.c b/src/basic/path-util.c
index 995f39f16e..221517303e 100644
--- a/src/basic/path-util.c
+++ b/src/basic/path-util.c
@@ -1139,5 +1139,12 @@ int path_simplify_and_warn(
                 return -EINVAL;
         }
 
+        if (!path_is_valid(path)) {
+                log_syntax(unit, LOG_ERR, filename, line, 0,
+                           "%s= path has invalid length (%zu bytes)%s.",
+                           lvalue, strlen(path), fatal ? "" : ", ignoring");
+                return -EINVAL;
+        }
+
         return 0;
 }
diff --git a/src/basic/path-util.h b/src/basic/path-util.h
index 78db41b855..094aa47c01 100644
--- a/src/basic/path-util.h
+++ b/src/basic/path-util.h
@@ -97,12 +97,24 @@ int mkfs_exists(const char *fstype);
 /* Iterates through the path prefixes of the specified path, going up
  * the tree, to root. Also returns "" (and not "/"!) for the root
  * directory. Excludes the specified directory itself */
-#define PATH_FOREACH_PREFIX(prefix, path) \
-        for (char *_slash = ({ path_simplify(strcpy(prefix, path), false); streq(prefix, "/") ? NULL : strrchr(prefix, '/'); }); _slash && ((*_slash = 0), true); _slash = strrchr((prefix), '/'))
+#define PATH_FOREACH_PREFIX(prefix, path)                               \
+        for (char *_slash = ({                                          \
+                                path_simplify(strcpy(prefix, path), false); \
+                                streq(prefix, "/") ? NULL : strrchr(prefix, '/'); \
+                        });                                             \
+             _slash && ((*_slash = 0), true);                           \
+             _slash = strrchr((prefix), '/'))
 
 /* Same as PATH_FOREACH_PREFIX but also includes the specified path itself */
-#define PATH_FOREACH_PREFIX_MORE(prefix, path) \
-        for (char *_slash = ({ path_simplify(strcpy(prefix, path), false); if (streq(prefix, "/")) prefix[0] = 0; strrchr(prefix, 0); }); _slash && ((*_slash = 0), true); _slash = strrchr((prefix), '/'))
+#define PATH_FOREACH_PREFIX_MORE(prefix, path)                          \
+        for (char *_slash = ({                                          \
+                                path_simplify(strcpy(prefix, path), false); \
+                                if (streq(prefix, "/"))                 \
+                                        prefix[0] = 0;                  \
+                                strrchr(prefix, 0);                     \
+                        });                                             \
+             _slash && ((*_slash = 0), true);                           \
+             _slash = strrchr((prefix), '/'))
 
 char *prefix_root(const char *root, const char *path);
 
diff --git a/src/core/device.c b/src/core/device.c
index ec05695e57..960f403718 100644
--- a/src/core/device.c
+++ b/src/core/device.c
@@ -839,7 +839,7 @@ static void device_enumerate(Manager *m) {
 
         r = sd_device_enumerator_new(&e);
         if (r < 0) {
-                log_error_errno(r, "Failed to alloacte device enumerator: %m");
+                log_error_errno(r, "Failed to allocate device enumerator: %m");
                 goto fail;
         }
 
diff --git a/src/core/manager.c b/src/core/manager.c
index 871047e628..2398dcf4ea 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -2222,7 +2222,7 @@ static unsigned manager_dispatch_dbus_queue(Manager *m) {
 
 static int manager_dispatch_cgroups_agent_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
         Manager *m = userdata;
-        char buf[PATH_MAX+1];
+        char buf[PATH_MAX];
         ssize_t n;
 
         n = recv(fd, buf, sizeof(buf), 0);
diff --git a/src/core/unit.c b/src/core/unit.c
index e1b6e9f11c..a9303a0f3f 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -4580,7 +4580,6 @@ int unit_kill_context(
 
 int unit_require_mounts_for(Unit *u, const char *path, UnitDependencyMask mask) {
         _cleanup_free_ char *p = NULL;
-        char *prefix;
         UnitDependencyInfo di;
         int r;
 
@@ -4620,7 +4619,7 @@ int unit_require_mounts_for(Unit *u, const char *path, UnitDependencyMask mask)
                 return r;
         p = NULL;
 
-        prefix = alloca(strlen(path) + 1);
+        char prefix[strlen(path) + 1];
         PATH_FOREACH_PREFIX_MORE(prefix, path) {
                 Set *x;
 
diff --git a/test/fuzz/fuzz-unit-file/oss-fuzz-11569 b/test/fuzz/fuzz-unit-file/oss-fuzz-11569
new file mode 100644
index 0000000000..c49b8c6b1c
Binary files /dev/null and b/test/fuzz/fuzz-unit-file/oss-fuzz-11569 differ