From: Roy Marples <roy@marples.name>
Date: Sun, 5 May 2019 11:46:32 +0000 (+0100)
Subject: sa: Ensure sa_addrtop has a buffer to write to
X-Git-Tag: v8.0.0~42
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b1ec97d0587776100fc4b4276b600f19e80cbc71;p=thirdparty%2Fdhcpcd.git

sa: Ensure sa_addrtop has a buffer to write to

While here, if sa_family is AF_UNSPEC print a blank string.
---

diff --git a/src/sa.c b/src/sa.c
index ca63493e..bc9f5d6c 100644
--- a/src/sa.c
+++ b/src/sa.c
@@ -364,6 +364,13 @@ sa_addrtop(const struct sockaddr *sa, char *buf, socklen_t len)
 	const void *addr;
 
 	assert(buf != NULL);
+	assert(len > 0);
+
+	if (sa->sa_family == 0) {
+		*buf = '\0';
+		return NULL;
+	}
+
 #ifdef AF_LINK
 #ifndef CLLADDR
 #define CLLADDR(sdl) (const void *)((sdl)->sdl_data + (sdl)->sdl_nlen)