From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Tue, 16 Mar 2021 15:23:51 +0000 (+0900)
Subject: dhcp6: fix wrong length for IA_PD dhcp6 option
X-Git-Tag: v248-rc4~9
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fa92d38428cdac260e72e280bf1d43539f4ea805;p=thirdparty%2Fsystemd.git

dhcp6: fix wrong length for IA_PD dhcp6 option

Fixes an issue introduced by 73b49d433c2c8e6304c8b82538bd4231d070fce4.

When PrefixDelegationHint= is not set, dhcp6_option_append_pd() sets
wrong length for IA_PD option, as `r` is `-EINVAL`.

Fixes #19021.
---

diff --git a/src/libsystemd-network/dhcp6-option.c b/src/libsystemd-network/dhcp6-option.c
index 93140160245..91162d636bf 100644
--- a/src/libsystemd-network/dhcp6-option.c
+++ b/src/libsystemd-network/dhcp6-option.c
@@ -257,9 +257,9 @@ int dhcp6_option_append_pd(uint8_t **buf, size_t *buflen, const DHCP6IA *pd, con
                 len += r;
         }
 
-        if (hint_pd_prefix) {
+        if (hint_pd_prefix && hint_pd_prefix->iapdprefix.prefixlen > 0) {
                 r = option_append_pd_prefix(buf, buflen, hint_pd_prefix);
-                if (r < 0 && r != -EINVAL)
+                if (r < 0)
                         return r;
 
                 len += r;