[krb5/f15] - apply upstream patch to fix a null pointer dereference when processing TGS requests (CVE-2011-1530

[Nalin Dahyabhai]

commit e57318ef461f99fe7bf2c542d8b8bb010bea640c
Author: Nalin Dahyabhai <nalin at dahyabhai.net>
Date:   Tue Dec 6 14:10:19 2011 -0500

    - apply upstream patch to fix a null pointer dereference when processing TGS requests (CVE-2011-1530, #753748)

 2011-007-patch.txt |   40 ++++++++++++++++++++++++++++++++++++++++
 1 files changed, 40 insertions(+), 0 deletions(-)
---
diff --git a/2011-007-patch.txt b/2011-007-patch.txt
new file mode 100644
index 0000000..336a4ad
--- /dev/null
+++ b/2011-007-patch.txt
@@ -0,0 +1,40 @@
+diff --git a/src/kdc/Makefile.in b/src/kdc/Makefile.in
+index f46cad3..102fbaa 100644
+--- a/src/kdc/Makefile.in
++++ b/src/kdc/Makefile.in
+@@ -67,6 +67,7 @@ check-unix:: rtest
+ 
+ check-pytests::
+ 	$(RUNPYTEST) $(srcdir)/t_workers.py $(PYTESTFLAGS)
++	$(RUNPYTEST) $(srcdir)/t_emptytgt.py $(PYTESTFLAGS)
+ 
+ install::
+ 	$(INSTALL_PROGRAM) krb5kdc ${DESTDIR}$(SERVER_BINDIR)/krb5kdc
+diff --git a/src/kdc/do_tgs_req.c b/src/kdc/do_tgs_req.c
+index c169c54..840a2ef 100644
+--- a/src/kdc/do_tgs_req.c
++++ b/src/kdc/do_tgs_req.c
+@@ -243,7 +243,8 @@ tgt_again:
+                     if (!tgs_1 || !data_eq(*server_1, *tgs_1)) {
+                         errcode = find_alternate_tgs(request, &server);
+                         firstpass = 0;
+-                        goto tgt_again;
++                        if (errcode == 0)
++                            goto tgt_again;
+                     }
+                 }
+                 status = "UNKNOWN_SERVER";
+diff --git a/src/kdc/t_emptytgt.py b/src/kdc/t_emptytgt.py
+new file mode 100644
+index 0000000..1760bcd
+--- /dev/null
++++ b/src/kdc/t_emptytgt.py
+@@ -0,0 +1,8 @@
++#!/usr/bin/python
++from k5test import *
++
++realm = K5Realm(start_kadmind=False, create_host=False)
++output = realm.run_as_client([kvno, 'krbtgt/'], expected_code=1)
++if 'not found in Kerberos database' not in output:
++    fail('TGT lookup for empty realm failed in unexpected way')
++success('Empty tgt lookup.')