lib: protect printfrr extensions from NULL input

Protect the lib printfrr extension handlers from NULL inputs.

Signed-off-by: Mark Stapp <mjs@voltanet.io>

1 files changed, 32 insertions, 27 deletions

diff --git a/lib/sockunion.c b/lib/sockunion.c
index 1dbf77efa4..c701da1e03 100644
--- a/lib/sockunion.c
+++ b/lib/sockunion.c
@@ -673,39 +673,44 @@ static ssize_t printfrr_psu(char *buf, size_t bsz, const char *fmt,
 	bool endflags = false;
 	ssize_t consumed = 2;
 
-	while (!endflags) {
-		switch (fmt[consumed++]) {
-		case 'p':
-			include_port = true;
+	if (su) {
+		while (!endflags) {
+			switch (fmt[consumed++]) {
+			case 'p':
+				include_port = true;
+				break;
+			default:
+				consumed--;
+				endflags = true;
+				break;
+			}
+		};
+
+		switch (sockunion_family(su)) {
+		case AF_UNSPEC:
+			bprintfrr(&fb, "(unspec)");
 			break;
-		default:
-			consumed--;
-			endflags = true;
+		case AF_INET:
+			inet_ntop(AF_INET, &su->sin.sin_addr, buf, bsz);
+			fb.pos += strlen(fb.buf);
+			if (include_port)
+				bprintfrr(&fb, ":%d", su->sin.sin_port);
+			break;
+		case AF_INET6:
+			inet_ntop(AF_INET6, &su->sin6.sin6_addr, buf, bsz);
+			fb.pos += strlen(fb.buf);
+			if (include_port)
+				bprintfrr(&fb, ":%d", su->sin6.sin6_port);
 			break;
+		default:
+			bprintfrr(&fb, "(af %d)", sockunion_family(su));
 		}
-	};
 
-	switch (sockunion_family(su)) {
-	case AF_UNSPEC:
-		bprintfrr(&fb, "(unspec)");
-		break;
-	case AF_INET:
-		inet_ntop(AF_INET, &su->sin.sin_addr, buf, bsz);
-		fb.pos += strlen(fb.buf);
-		if (include_port)
-			bprintfrr(&fb, ":%d", su->sin.sin_port);
-		break;
-	case AF_INET6:
-		inet_ntop(AF_INET6, &su->sin6.sin6_addr, buf, bsz);
-		fb.pos += strlen(fb.buf);
-		if (include_port)
-			bprintfrr(&fb, ":%d", su->sin6.sin6_port);
-		break;
-	default:
-		bprintfrr(&fb, "(af %d)", sockunion_family(su));
+		fb.pos[0] = '\0';
+	} else {
+		strlcpy(buf, "NULL", bsz);
 	}
 
-	fb.pos[0] = '\0';
 	return consumed;
 }