multi-statement CHECK_RANGE() macro isn't safe for all placements, and

needs to use "do {} while 0" idiom; all callers need repair also.
Discovered by jsg

diff --git a/usr.sbin/ldapd/syntax.c b/usr.sbin/ldapd/syntax.c
index 27f7352..fb3a3c0 100644 (file)
--- a/usr.sbin/ldapd/syntax.c
+++ b/usr.sbin/ldapd/syntax.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: syntax.c,v 1.3 2015/10/11 03:23:28 guenther Exp $ */
+/*     $OpenBSD: syntax.c,v 1.4 2017/04/13 14:48:31 deraadt Exp $ */
 
 /*
  * Copyright (c) 2010 Martin Hedenfalk <martin@bzero.se>
@@ -266,20 +266,22 @@ syntax_is_time(struct schema *schema, char *value, size_t len, int gen)
        int      n;
        char    *p = value;
 
-#define CHECK_RANGE(min, max)  \
+#define CHECK_RANGE(min, max) \
+       do {                                            \
                if (!isdigit((unsigned char)p[0]) ||    \
                    !isdigit((unsigned char)p[1]))      \
                        return 0;                       \
                n = (p[0] - '0') * 10 + (p[1] - '0');   \
                if (n < min || n > max)                 \
                        return 0;                       \
-               p += 2;
+               p += 2;                                 \
+       } while (0)
 
        if (gen)
-               CHECK_RANGE(0, 99)              /* century */
-       CHECK_RANGE(0, 99)                      /* year */
-       CHECK_RANGE(1, 12)                      /* month */
-       CHECK_RANGE(1, 31)                      /* day */
+               CHECK_RANGE(0, 99);             /* century */
+       CHECK_RANGE(0, 99);                     /* year */
+       CHECK_RANGE(1, 12);                     /* month */
+       CHECK_RANGE(1, 31);                     /* day */
        /* FIXME: should check number of days in month */
        CHECK_RANGE(0, 23);                     /* hour */