1 files changed, 4 insertions, 0 deletions
diff --git a/src/rfc1035.c b/src/rfc1035.c
index 26a2254..de009d0 100644
--- a/src/rfc1035.c
+++ b/src/rfc1035.c
@@ -564,8 +564,12 @@ static size_t add_pseudoheader(struct dns_header *header, size_t plen, unsigned
   
   if (optno != 0)
     {
+      if (p + 4 > limit)
+        return plen; /* Too big */
       PUTSHORT(optno, p);
       PUTSHORT(optlen, p);
+      if (p + optlen > limit)
+        return plen; /* Too big */
       memcpy(p, opt, optlen);
       p += optlen;  
     }