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From 6a0b00f0d66490e074323d04782e75c4ba8a3f8d Mon Sep 17 00:00:00 2001
From: Simon Kelley <simon@thekelleys.org.uk>
Date: Mon, 25 Sep 2017 20:19:55 +0100
Subject: [PATCH 8/9] Misc code cleanups arising from Google analysis. No
 security impleications or CVEs.

---
 src/edns0.c   | 2 +-
 src/rfc1035.c | 4 +++-
 src/rfc2131.c | 2 +-
 3 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/edns0.c b/src/edns0.c
index 89b2692..7ed5a47 100644
--- a/src/edns0.c
+++ b/src/edns0.c
@@ -159,7 +159,7 @@ size_t add_pseudoheader(struct dns_header *header, size_t plen, unsigned char *l
 	      /* delete option if we're to replace it. */
 	      p -= 4;
 	      rdlen -= len + 4;
-	      memcpy(p, p+len+4, rdlen - i);
+	      memmove(p, p+len+4, rdlen - i);
 	      PUTSHORT(rdlen, lenp);
 	      lenp -= 2;
 	    }
diff --git a/src/rfc1035.c b/src/rfc1035.c
index 826f8a4..27af023 100644
--- a/src/rfc1035.c
+++ b/src/rfc1035.c
@@ -37,7 +37,7 @@ int extract_name(struct dns_header *header, size_t plen, unsigned char **pp,
 	/* end marker */
 	{
 	  /* check that there are the correct no of bytes after the name */
-	  if (!CHECK_LEN(header, p, plen, extrabytes))
+	  if (!CHECK_LEN(header, p1 ? p1 : p, plen, extrabytes))
 	    return 0;
 	  
 	  if (isExtract)
@@ -498,6 +498,8 @@ static unsigned char *do_doctor(unsigned char *p, int count, struct dns_header *
 	    {
 	      unsigned int i, len = *p1;
 	      unsigned char *p2 = p1;
+	      if ((p1 + len - p) >= rdlen)
+	        return 0; /* bad packet */
 	      /* make counted string zero-term  and sanitise */
 	      for (i = 0; i < len; i++)
 		{
diff --git a/src/rfc2131.c b/src/rfc2131.c
index f7c1f80..f3a7e53 100644
--- a/src/rfc2131.c
+++ b/src/rfc2131.c
@@ -157,7 +157,7 @@ size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
 	  for (offset = 0; offset < (len - 5); offset += elen + 5)
 	    {
 	      elen = option_uint(opt, offset + 4 , 1);
-	      if (option_uint(opt, offset, 4) == BRDBAND_FORUM_IANA)
+	      if (option_uint(opt, offset, 4) == BRDBAND_FORUM_IANA && offset + elen + 5 <= len)
 		{
 		  unsigned char *x = option_ptr(opt, offset + 5);
 		  unsigned char *y = option_ptr(opt, offset + elen + 5);
-- 
2.9.5