From: Philippe Antoine <p.antoine@catenacyber.fr>
Date: Mon, 26 Mar 2018 08:23:51 +0000 (+0200)
Subject: Adds multiple checks to avoid buffer over reads
X-Git-Tag: OpenSSL_1_1_0i~225
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=cdabf89acf65040560e0242cb70d945f3f3bdd5c;p=oweals%2Fopenssl.git

Adds multiple checks to avoid buffer over reads

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/5686)
---

diff --git a/ssl/t1_trce.c b/ssl/t1_trce.c
index 76bdf792ae..e5b4085c20 100644
--- a/ssl/t1_trce.c
+++ b/ssl/t1_trce.c
@@ -725,6 +725,8 @@ static int ssl_print_extensions(BIO *bio, int indent, int server,
         BIO_puts(bio, "No Extensions\n");
         return 1;
     }
+    if (msglen < 2)
+        return 0;
     extslen = (msg[0] << 8) | msg[1];
     if (extslen != msglen - 2)
         return 0;
@@ -1092,6 +1094,8 @@ static int ssl_print_cert_request(BIO *bio, int indent, SSL *s,
     msglen -= xlen + 2;
 
  skip_sig:
+    if (msglen < 2)
+        return 0;
     xlen = (msg[0] << 8) | msg[1];
     BIO_indent(bio, indent, 80);
     if (msglen < xlen + 2)
@@ -1271,7 +1275,15 @@ void SSL_trace(int write_p, int version, int content_type,
     switch (content_type) {
     case SSL3_RT_HEADER:
         {
-            int hvers = msg[1] << 8 | msg[2];
+            int hvers;
+
+            /* avoid overlapping with length at the end of buffer */
+            if (msglen < (SSL_IS_DTLS(ssl) ? 13 : 5)) {
+                    BIO_puts(bio, write_p ? "Sent" : "Received");
+                    ssl_print_hex(bio, 0, " too short message", msg, msglen);
+                    break;
+                }
+            hvers = msg[1] << 8 | msg[2];
             BIO_puts(bio, write_p ? "Sent" : "Received");
             BIO_printf(bio, " Record\nHeader:\n  Version = %s (0x%x)\n",
                        ssl_trace_str(hvers, ssl_version_tbl), hvers);