From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Mon, 22 Feb 2021 12:59:24 +0000 (+0900)
Subject: dhcp6: do not use input value before checking
X-Git-Tag: v248-rc3~127^2~3
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cf6c33bd6b6ca606f0756312bd73ae066c6aa9a8;p=thirdparty%2Fsystemd.git

dhcp6: do not use input value before checking
---

diff --git a/src/libsystemd-network/dhcp6-option.c b/src/libsystemd-network/dhcp6-option.c
index 9f47c1bbe4c..48eef8950b6 100644
--- a/src/libsystemd-network/dhcp6-option.c
+++ b/src/libsystemd-network/dhcp6-option.c
@@ -41,14 +41,15 @@ typedef struct DHCP6PDPrefixOption {
 #define DHCP6_OPTION_IA_PD_LEN (sizeof(struct ia_pd))
 #define DHCP6_OPTION_IA_TA_LEN (sizeof(struct ia_ta))
 
-static int option_append_hdr(uint8_t **buf, size_t *buflen, uint16_t optcode,
-                             size_t optlen) {
-        DHCP6Option *option = (DHCP6Option*) *buf;
+static int option_append_hdr(uint8_t **buf, size_t *buflen, uint16_t optcode, size_t optlen) {
+        DHCP6Option *option;
 
         assert_return(buf, -EINVAL);
         assert_return(*buf, -EINVAL);
         assert_return(buflen, -EINVAL);
 
+        option = (DHCP6Option*) *buf;
+
         if (optlen > 0xffff || *buflen < optlen + offsetof(DHCP6Option, data))
                 return -ENOBUFS;