!34 【Mainline】Fix CVE-2021-37750

From: @gys66
Reviewed-by: @zhujianwei001
Signed-off-by: @zhujianwei001

backport-CVE-2021-37750.patch

@@ -0,0 +1,46 @@
+From d775c95af7606a51bf79547a94fa52ddd1cb7f49 Mon Sep 17 00:00:00 2001
+From: Greg Hudson <ghudson@mit.edu>
+Date: Tue, 3 Aug 2021 01:15:27 -0400
+Subject: [PATCH] Fix KDC null deref on TGS inner body null server
+
+After the KDC decodes a FAST inner body, it does not check for a null
+server.  Prior to commit 39548a5b17bbda9eeb63625a201cfd19b9de1c5b this
+would typically result in an error from krb5_unparse_name(), but with
+the addition of get_local_tgt() it results in a null dereference.  Add
+a null check.
+
+Reported by Joseph Sutton of Catalyst.
+
+CVE-2021-37750:
+
+In MIT krb5 releases 1.14 and later, an authenticated attacker can
+cause a null dereference in the KDC by sending a FAST TGS request with
+no server field.
+
+ticket: 9008 (new)
+tags: pullup
+target_version: 1.19-next
+target_version: 1.18-next
+---
+ src/kdc/do_tgs_req.c | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+diff --git a/src/kdc/do_tgs_req.c b/src/kdc/do_tgs_req.c
+index 582e497..32dc65f 100644
+--- a/src/kdc/do_tgs_req.c
++++ b/src/kdc/do_tgs_req.c
+@@ -207,6 +207,11 @@ process_tgs_req(krb5_kdc_req *request, krb5_data *pkt,
+         status = "FIND_FAST";
+         goto cleanup;
+     }
++    if (sprinc == NULL) {
++        status = "NULL_SERVER";
++        errcode = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
++        goto cleanup;
++    }
+ 
+     errcode = get_local_tgt(kdc_context, &sprinc->realm, header_server,
+                             &local_tgt, &local_tgt_storage, &local_tgt_key);
+-- 
+1.8.3.1
+

krb5.spec

@@ -3,7 +3,7 @@
 
 Name:     krb5
 Version:  1.19.1
-Release:  2
+Release:  3
 Summary:  The Kerberos network authentication protocol
 License:  MIT
 URL:      http://web.mit.edu/kerberos/www/
@@ -27,6 +27,7 @@ Patch4: fix-debuginfo-with-y.tab.c.patch
 Patch5: Remove-3des-support.patch
 Patch6: FIPS-with-PRNG-and-RADIUS-and-MD4.patch
 Patch7: backport-CVE-2021-36222.patch
+Patch8: backport-CVE-2021-37750.patch
 
 BuildRequires:  gettext
 BuildRequires:  gcc make automake autoconf pkgconfig pam-devel libselinux-devel byacc
@@ -318,6 +319,9 @@ make -C src check || :
 %{_mandir}/man8/*
 
 %changelog
+* Tue Aug 24 2021 gaoyusong <gaoyusong1@huawei.com> - 1.19.1-3
+- Fix CVE-2021-37750
+
 * Wed Jul 21 2021 yixiangzhike <zhangxingliang3@huawei.com> - 1.19.1-2
 - Fix CVE-2021-36222