iservice: make sure registry string is terminated

When reading the interface domains from the registry, check that the
string is zero terminated, since the code in GetItfDnsDomains depends
on the fact when doing size calculations during the conversion.

Reported-by: Marc Heuse <marc@srlabs.de>
Reported-by: stephan@srlabs.de
Change-Id: Icaeca22bdbd8ead0cb12345b1bcc2b5c0f46236f
Signed-off-by: Heiko Hund <heiko@ist.eigentlich.net>
Acked-by: Gert Doering <gert@greenie.muc.de>
Gerrit URL: https://gerrit.openvpn.net/c/openvpn/+/1392
Message-Id: <20251123115851.19555-1-gert@greenie.muc.de>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg34610.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>

diff --git a/src/openvpnserv/interactive.c b/src/openvpnserv/interactive.c
index d778e8984a32219c65bc6b4d312cc24dc2993393..860375d17d30cbe1c52a069f60282719b6534dd0 100644 (file)
--- a/src/openvpnserv/interactive.c
+++ b/src/openvpnserv/interactive.c
@@ -2163,7 +2163,7 @@ GetItfDnsDomains(HKEY itf, PCWSTR search_domains, PWSTR domains, PDWORD size)
     {
         *size = buf_size;
         err = RegGetValueW(itf, NULL, values[i], RRF_RT_REG_SZ, NULL, (PBYTE)domains, size);
-        if (!err && *size > one_glyph && wcschr(domains, '.'))
+        if (!err && *size > one_glyph && domains[(*size / one_glyph) - 1] == '\0' && wcschr(domains, '.'))
         {
             /*
              * Found domain(s), now convert them: