From: Heiko Hund Date: Wed, 26 Nov 2025 10:34:21 +0000 (+0100) Subject: iservice: fix calculation of converted domains size X-Git-Tag: v2.7_rc3~15 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ac6c9d65701ed6d41691497846a47cb4e72b2878;p=thirdparty%2Fopenvpn.git iservice: fix calculation of converted domains size To keep track of how much of the buffer is already used, the difference of the current position and the start of the buffer needs to be multiplied with the size of a character / glyph to bet the byte count, with which calculations are done further down below. Reported-by: Marc Heuse Reported-by: stephan@srlabs.de Change-Id: I16f9426e57f4802ba038ab51f5b70161464b9428 Signed-off-by: Heiko Hund Acked-by: Gert Doering Gerrit URL: https://gerrit.openvpn.net/c/openvpn/+/1390 Message-Id: <20251126103427.4085-1-gert@greenie.muc.de> Signed-off-by: Gert Doering --- diff --git a/src/openvpnserv/interactive.c b/src/openvpnserv/interactive.c index dbb5a4b38..ed3c92891 100644 --- a/src/openvpnserv/interactive.c +++ b/src/openvpnserv/interactive.c @@ -2181,8 +2181,11 @@ GetItfDnsDomains(HKEY itf, PCWSTR search_domains, PWSTR domains, PDWORD size) *comma = '\0'; } - /* Ignore itf domains which match a pushed search domain */ size_t domain_len = wcslen(pos); + size_t domain_size = domain_len * one_glyph; + size_t converted_size = (pos - domains) * one_glyph; + + /* Ignore itf domains which match a pushed search domain */ if (ListContainsDomain(search_domains, pos, domain_len)) { if (comma) @@ -2199,11 +2202,14 @@ GetItfDnsDomains(HKEY itf, PCWSTR search_domains, PWSTR domains, PDWORD size) } } - /* Check for enough space to convert this domain */ - domain_len += 1; /* leading dot */ - size_t converted_size = pos - domains; - size_t domain_size = domain_len * one_glyph; + /* Add space for the leading dot */ + domain_len += 1; + domain_size += one_glyph; + + /* Space for the terminating zeros */ size_t extra_size = 2 * one_glyph; + + /* Check for enough space to convert this domain */ if (converted_size + domain_size + extra_size > buf_size) { /* Domain doesn't fit, bad luck if it's the first one */