From 3947ab0069e443e72debe26379b8517fac8f6e41 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 a8d0167..0552d38 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 78410d6..917bac2 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)
@@ -485,6 +485,8 @@ 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 75893a6..71d5846 100644
--- a/src/rfc2131.c
+++ b/src/rfc2131.c
@@ -155,7 +155,7 @@ 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