fix potential buffer overflow when txt records are forged

Signed-off-by: John Crispin <blogic@openwrt.org>

diff --git a/cache.c b/cache.c
index e775537..cdc4a79 100644 (file)
--- a/cache.c
+++ b/cache.c
@@ -274,7 +274,7 @@ cache_answer(struct interface *iface, uint8_t *base, int blen, char *name, struc
                        uint8_t v = *p;
 
                        *p = '\0';
-                       if (v)
+                       if (v && p + v < &rdata_buffer[rdlength])
                                p += v + 1;
                } while (*p);
                break;