krb5 commit [krb5-1.12]: Fix returning KDB_NOENTRY in find_alternate_tgs()

[Tom Yu]

https://github.com/krb5/krb5/commit/b6aedcc5c31a19c071e6fec0bb9119f177d142d1
commit b6aedcc5c31a19c071e6fec0bb9119f177d142d1
Author: Nalin Dahyabhai <nalin at dahyabhai.net>
Date:   Thu Feb 20 16:01:49 2014 -0500

    Fix returning KDB_NOENTRY in find_alternate_tgs()
    
    After searching for a cross-realm TGS entry to provide to a client as a
    referral, if we're all set to return a success code but aren't actually
    returning an entry, we should be returning an error.  We might not do so
    because we don't compare the right value against NULL.
    
    This corrects an error in a redundant check in the patch for
    CVE-2013-1417.  The error in the check cannot occur in practice
    because the other part of the patch for CVE-2013-1417 prevents it, but
    static analyzers can flag the erroneous check.
    
    [tlyu at mit.edu: edit commit message]
    
    (cherry picked from commit 90cbf4eb60d8ec3c083195ba4a050a31ea36be0b)
    
    ticket: 7881
    version_fixed: 1.12.2
    status: resolved

 src/kdc/do_tgs_req.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/src/kdc/do_tgs_req.c b/src/kdc/do_tgs_req.c
index 6bc4f15..d81b2b4 100644
--- a/src/kdc/do_tgs_req.c
+++ b/src/kdc/do_tgs_req.c
@@ -1117,7 +1117,7 @@ find_alternate_tgs(kdc_realm_t *kdc_active_realm, krb5_principal princ,
         goto cleanup;
     }
 cleanup:
-    if (retval == 0 && server_ptr == NULL)
+    if (retval == 0 && *server_ptr == NULL)
         retval = KRB5_KDB_NOENTRY;
     if (retval != 0)
         *status = "UNKNOWN_SERVER";