Don't rely on asprintf setting pointer to NULL on failure.

ok millert@ deraadt@ tom@

diff --git a/usr.sbin/rtadvd/dump.c b/usr.sbin/rtadvd/dump.c
index cafccad..bccfad7 100644 (file)
--- a/usr.sbin/rtadvd/dump.c
+++ b/usr.sbin/rtadvd/dump.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: dump.c,v 1.22 2017/04/02 22:57:20 deraadt Exp $       */
+/*     $OpenBSD: dump.c,v 1.23 2017/04/05 13:38:18 jca Exp $   */
 /*     $KAME: dump.c,v 1.27 2002/05/29 14:23:55 itojun Exp $   */
 
 /*
@@ -113,7 +113,7 @@ rtadvd_dump(void)
        int first;
        struct timeval now, next;
        char *origin, *vltime, *pltime, *flags;
-       char *vltimexpire=NULL, *pltimexpire=NULL;
+       char *vltimexpire, *pltimexpire;
        char ctimebuf[26];
 
        gettimeofday(&now, NULL);
@@ -186,16 +186,23 @@ rtadvd_dump(void)
                        default:
                                origin = "";
                        }
-                       if (pfx->vltimeexpire != 0)
+                       if (pfx->vltimeexpire != 0) {
                                /* truncate to onwire value */
-                               asprintf(&vltimexpire, "(decr,expire %u)",
+                               if (asprintf(&vltimexpire, "(decr,expire %u)",
                                    (u_int32_t)(pfx->vltimeexpire > now.tv_sec ?
-                                   pfx->vltimeexpire - now.tv_sec : 0));
-                       if (pfx->pltimeexpire != 0)
+                                   pfx->vltimeexpire - now.tv_sec : 0)) == -1)
+                                       vltimexpire = NULL;
+                       } else
+                               vltimexpire = NULL;
+
+                       if (pfx->pltimeexpire != 0) {
                                /* truncate to onwire value */
-                               asprintf(&pltimexpire, "(decr,expire %u)",
+                               if (asprintf(&pltimexpire, "(decr,expire %u)",
                                    (u_int32_t)(pfx->pltimeexpire > now.tv_sec ?
-                                   pfx->pltimeexpire - now.tv_sec : 0));
+                                   pfx->pltimeexpire - now.tv_sec : 0)) == -1)
+                                       pltimexpire = NULL;
+                       } else
+                               pltimexpire = NULL;
 
                        vltime = lifetime(pfx->validlifetime);
                        pltime = lifetime(pfx->preflifetime);