journal-importer: ignore invalid field at one more place

Fixes oss-fuzz#28817.
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=28817

man/localtime.xml

@@ -41,6 +41,9 @@
     symlink target name of <filename>/etc/localtime</filename>, this
     file may not be a normal file or hardlink.</para>
 
+    <para>If <filename>/etc/localtime</filename> is missing, the
+    default <literal>UTC</literal> timezone is used.</para>
+
     <para>The timezone may be overridden for individual programs by
     using the <varname>$TZ</varname> environment variable. See
     <citerefentry project='man-pages'><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>

man/systemd.netdev.xml

@@ -1629,9 +1629,16 @@
         <listitem>
           <para>Sets a comma-separated list of IP (v4 or v6) addresses with CIDR masks
           from which this peer is allowed to send incoming traffic and to
-          which outgoing traffic for this peer is directed. The catch-all
+          which outgoing traffic for this peer is directed.</para>
-          0.0.0.0/0 may be specified for matching all IPv4 addresses, and
+          <para>The catch-all 0.0.0.0/0 may be specified for matching all IPv4 addresses,
-          ::/0 may be specified for matching all IPv6 addresses. </para>
+          and ::/0 may be specified for matching all IPv6 addresses.</para>
+          <para>Note that this only affects "routing inside the network interface itself",
+          as in, which wireguard peer packets with a specific destination address are sent to,
+          and what source addresses are accepted from which peer.</para>
+          <para>To cause packets to be sent via wireguard in first place, a route needs
+          to be added, as well - either in the <literal>[Routes]</literal> section on the
+          <literal>.network</literal> matching the wireguard interface, or outside of networkd.
+          </para>
         </listitem>
       </varlistentry>
       <varlistentry>

src/shared/journal-importer.c

@@ -334,6 +334,16 @@ int journal_importer_process_data(JournalImporter *imp) {
                         if (r < 0)
                                 return r;
                 } else {
+                        if (!journal_field_valid(line, n - 1, true)) {
+                                char buf[64], *t;
+
+                                t = strndupa(line, n - 1);
+                                log_debug("Ignoring invalid field: \"%s\"",
+                                          cellescape(buf, sizeof buf, t));
+
+                                return 0;
+                        }
+
                         /* replace \n with = */
                         line[n-1] = '=';