From 31c8b265591a0aaa462a1f3eb5770661aaac67db Mon Sep 17 00:00:00 2001
From: Rich Salz <rsalz@openssl.org>
Date: Tue, 22 Aug 2017 11:44:41 -0400
Subject: [PATCH] Avoid out-of-bounds read

Fixes CVE 2017-3735

Reviewed-by: Kurt Roeckx <kurt@roeckx.be>
(Merged from https://github.com/openssl/openssl/pull/4276)

(cherry picked from commit b23171744b01e473ebbfd6edad70c1c3825ffbcd)
---
 crypto/x509v3/v3_addr.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/Cryptlib/OpenSSL/crypto/x509v3/v3_addr.c b/Cryptlib/OpenSSL/crypto/x509v3/v3_addr.c
index 1290dec9bb8..af080a04f2b 100644
--- a/Cryptlib/OpenSSL/crypto/x509v3/v3_addr.c
+++ b/Cryptlib/OpenSSL/crypto/x509v3/v3_addr.c
@@ -130,10 +130,12 @@ static int length_from_afi(const unsigned afi)
  */
 unsigned int v3_addr_get_afi(const IPAddressFamily *f)
 {
-    return ((f != NULL &&
-             f->addressFamily != NULL && f->addressFamily->data != NULL)
-            ? ((f->addressFamily->data[0] << 8) | (f->addressFamily->data[1]))
-            : 0);
+    if (f == NULL
+            || f->addressFamily == NULL
+            || f->addressFamily->data == NULL
+            || f->addressFamily->length < 2)
+        return 0;
+    return (f->addressFamily->data[0] << 8) | f->addressFamily->data[1];
 }
 
 /*
