File CVE-2014-8132-Fixup-dangling-pointers-in-ssh_packet_kexinit.patch of Package libssh.3640

commit 87ae95eb3c2f35d3e8e00eca43d0711ab2737ef5
Author: Jon Simons <jon@jonsimons.org>
Date:   Sat Oct 18 23:23:26 2014 -0700

    CVE-2014-8132: Fixup error path in ssh_packet_kexinit()
    
    Before this change, dangling pointers can be unintentionally left in the
    respective next_crypto kex methods slots.  Ensure to set all slots to
    NULL in the error-out path.
    
    Signed-off-by: Jon Simons <jon@jonsimons.org>
    Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
    (cherry picked from commit 2ced24ddd67a261dc364ad4d8958c068c1671ae7)

Index: libssh-0.6.3/src/kex.c
===================================================================
--- libssh-0.6.3.orig/src/kex.c
+++ libssh-0.6.3/src/kex.c
@@ -315,7 +315,7 @@ SSH_PACKET_CALLBACK(ssh_packet_kexinit){
   for (i = 0; i < KEX_METHODS_SIZE; i++) {
     str = buffer_get_ssh_string(packet);
     if (str == NULL) {
-      break;
+      goto error;
     }
 
     if (buffer_add_ssh_string(session->in_hashbuf, str) < 0) {
@@ -350,6 +350,11 @@ SSH_PACKET_CALLBACK(ssh_packet_kexinit){
 error:
   ssh_string_free(str);
   for (i = 0; i < SSH_KEX_METHODS; i++) {
+    if (server_kex) {
+        session->next_crypto->client_kex.methods[i] = NULL;
+    } else { /* client */
+        session->next_crypto->server_kex.methods[i] = NULL;
+    }
     SAFE_FREE(strings[i]);
   }