Check for malloc() failures.

Initial diff from Clemens Goessnitzer on tech@

Feedback and ok tb@

diff --git a/usr.sbin/rebound/rebound.c b/usr.sbin/rebound/rebound.c
index e118fa9..bfed237 100644 (file)
--- a/usr.sbin/rebound/rebound.c
+++ b/usr.sbin/rebound/rebound.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: rebound.c,v 1.98 2018/05/01 15:14:43 anton Exp $ */
+/* $OpenBSD: rebound.c,v 1.99 2018/09/08 13:17:19 anton Exp $ */
 /*
  * Copyright (c) 2015 Ted Unangst <tedu@openbsd.org>
  *
@@ -630,12 +630,12 @@ encodename(const char *name, unsigned char *buf)
        return totlen;
 }
 
-static void
+static int
 preloadcache(const char *name, uint16_t type, void *rdata, uint16_t rdatalen)
 {
-       struct dnspacket *req, *resp;
+       struct dnspacket *req = NULL, *resp = NULL;
        size_t reqlen, resplen;
-       struct dnscache *ent;
+       struct dnscache *ent = NULL;
        unsigned char *p;
        uint16_t len, class;
        uint32_t ttl;
@@ -643,6 +643,8 @@ preloadcache(const char *name, uint16_t type, void *rdata, uint16_t rdatalen)
        /* header + len + name + type + class */
        reqlen = sizeof(*req) + 1 + strlen(name) + 2 + 2;
        req = malloc(reqlen);
+       if (req == NULL)
+               goto fail;
 
        req->id = 0;
        req->flags = htons(0x100);
@@ -661,6 +663,8 @@ preloadcache(const char *name, uint16_t type, void *rdata, uint16_t rdatalen)
        /* req + name (compressed) + type + class + ttl + len + data */
        resplen = reqlen + 2 + 2 + 2 + 4 + 2 + rdatalen;
        resp = malloc(resplen);
+       if (resp == NULL)
+               goto fail;
        memcpy(resp, req, reqlen);
        resp->flags = htons(0x100 | 0x8000);    /* response */
        resp->ancount = htons(1);
@@ -682,6 +686,8 @@ preloadcache(const char *name, uint16_t type, void *rdata, uint16_t rdatalen)
        memcpy(p, rdata, rdatalen);
 
        ent = calloc(1, sizeof(*ent));
+       if (ent == NULL)
+               goto fail;
        ent->req = req;
        ent->reqlen = reqlen;
        ent->resp = resp;
@@ -689,7 +695,13 @@ preloadcache(const char *name, uint16_t type, void *rdata, uint16_t rdatalen)
        ent->permanent = 1;
 
        RB_INSERT(cachetree, &cachetree, ent);
+       return 0;
 
+fail:
+       free(req);
+       free(resp);
+       free(ent);
+       return -1;
 }
 
 static void
@@ -699,7 +711,8 @@ preloadA(const char *name, const char *ip)
 
        inet_aton(ip, &in);
 
-       preloadcache(name, htons(1), &in, 4);
+       if (preloadcache(name, htons(1), &in, 4) == -1)
+               logerr("failed to add cache entry for %s", name);
 }
 
 static void
@@ -715,7 +728,8 @@ preloadPTR(const char *ip, const char *name)
 
        encodename(name, namebuf);
 
-       preloadcache(ipbuf, htons(12), namebuf, 1 + strlen(namebuf));
+       if (preloadcache(ipbuf, htons(12), namebuf, 1 + strlen(namebuf)) == -1)
+               logerr("failed to add cache entry for %s", ip);
 }
 
 static int