krb5 commit [krb5-1.12]: Fix krb5_copy_context

[Tom Yu]

https://github.com/krb5/krb5/commit/13cfe6aad050732cb9fbb025715e7049db6b5a9b
commit 13cfe6aad050732cb9fbb025715e7049db6b5a9b
Author: Tom Yu <tlyu at mit.edu>
Date:   Wed Jan 8 17:40:19 2014 -0500

    Fix krb5_copy_context
    
    krb5_copy_context has been broken since 1.8 (it broke in r22456)
    because k5_copy_etypes crashes on null enctype lists.  Subsequent
    additions to the context structure were not reflected in
    krb5_copy_context, creating double-free bugs.  Make k5_copy_etypes
    handle null input and account for all new fields in krb5_copy_context.
    Reported by Arran Cudbard-Bell.
    
    (back ported from commit c452644d91d57d8b05ef396a029e34d0c7a48920)
    
    ticket: 7807

 src/lib/krb5/krb/copy_ctx.c   |   14 ++++++++++++++
 src/lib/krb5/krb/etype_list.c |    2 ++
 2 files changed, 16 insertions(+), 0 deletions(-)

diff --git a/src/lib/krb5/krb/copy_ctx.c b/src/lib/krb5/krb/copy_ctx.c
index 5d84170..2a61ed4 100644
--- a/src/lib/krb5/krb/copy_ctx.c
+++ b/src/lib/krb5/krb/copy_ctx.c
@@ -77,6 +77,14 @@ krb5_copy_context(krb5_context ctx, krb5_context *nctx_out)
     nctx->ser_ctx_count = 0;
     nctx->ser_ctx = NULL;
     nctx->prompt_types = NULL;
+    nctx->preauth_context = NULL;
+    nctx->ccselect_handles = NULL;
+    nctx->localauth_handles = NULL;
+    nctx->hostrealm_handles = NULL;
+    nctx->kdblog_context = NULL;
+    nctx->trace_callback = NULL;
+    nctx->trace_callback_data = NULL;
+    nctx->plugin_base_dir = NULL;
     nctx->os_context.default_ccname = NULL;
 
     memset(&nctx->libkrb5_plugins, 0, sizeof(nctx->libkrb5_plugins));
@@ -84,6 +92,7 @@ krb5_copy_context(krb5_context ctx, krb5_context *nctx_out)
     nctx->locate_fptrs = NULL;
 
     memset(&nctx->err, 0, sizeof(nctx->err));
+    memset(&nctx->plugins, 0, sizeof(nctx->plugins));
 
     ret = k5_copy_etypes(ctx->in_tkt_etypes, &nctx->in_tkt_etypes);
     if (ret)
@@ -103,6 +112,11 @@ krb5_copy_context(krb5_context ctx, krb5_context *nctx_out)
     ret = krb5_get_profile(ctx, &nctx->profile);
     if (ret)
         goto errout;
+    nctx->plugin_base_dir = strdup(ctx->plugin_base_dir);
+    if (nctx->plugin_base_dir == NULL) {
+        ret = ENOMEM;
+        goto errout;
+    }
 
 errout:
     if (ret) {
diff --git a/src/lib/krb5/krb/etype_list.c b/src/lib/krb5/krb/etype_list.c
index 9efe2e0..71f664f 100644
--- a/src/lib/krb5/krb/etype_list.c
+++ b/src/lib/krb5/krb/etype_list.c
@@ -49,6 +49,8 @@ k5_copy_etypes(const krb5_enctype *old_list, krb5_enctype **new_list)
     krb5_enctype *list;
 
     *new_list = NULL;
+    if (old_list == NULL)
+        return 0;
     count = k5_count_etypes(old_list);
     list = malloc(sizeof(krb5_enctype) * (count + 1));
     if (list == NULL)