gnu: openldap: Fix CVE-2020-12243.

* gnu/packages/openldap.scm (openldap)[replacement]: New field.
(openldap/fixed): New variable.
* gnu/packages/patches/openldap-CVE-2020-12243.patch: New file.
* gnu/local.mk (dist_patch_DATA): Register it.

2 files changed, 134 insertions, 0 deletions

diff --git a/gnu/packages/openldap.scm b/gnu/packages/openldap.scm
index de8239b7fe..aa51520654 100644
--- a/gnu/packages/openldap.scm
+++ b/gnu/packages/openldap.scm
@@ -5,6 +5,7 @@
 ;;; Copyright © 2017, 2018, 2019 Ricardo Wurmus <rekado@elephly.net>
 ;;; Copyright © 2018 Tobias Geerinckx-Rice <me@tobias.gr>
 ;;; Copyright © 2020 Lars-Dominik Braun <ldb@leibniz-psychology.org>
+;;; Copyright © 2020 Efraim Flashner <efraim@flashner.co.il>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -57,6 +58,7 @@
 
 (define-public openldap
   (package
+   (replacement openldap/fixed)
    (name "openldap")
    (version "2.4.47")
    (source (origin
@@ -110,6 +112,13 @@
    (license openldap2.8)
    (home-page "https://www.openldap.org/")))
 
+(define openldap/fixed
+  (package
+    (inherit openldap)
+    (source
+      (origin (inherit (package-source openldap))
+              (patches (search-patches "openldap-CVE-2020-12243.patch"))))))
+
 (define-public nss-pam-ldapd
   (package
     (name "nss-pam-ldapd")
diff --git a/gnu/packages/patches/openldap-CVE-2020-12243.patch b/gnu/packages/patches/openldap-CVE-2020-12243.patch
new file mode 100644
index 0000000000..6321998198
--- /dev/null
+++ b/gnu/packages/patches/openldap-CVE-2020-12243.patch
@@ -0,0 +1,125 @@
+From 98464c11df8247d6a11b52e294ba5dd4f0380440 Mon Sep 17 00:00:00 2001
+From: Howard Chu <hyc@openldap.org>
+Date: Thu, 16 Apr 2020 01:08:19 +0100
+Subject: [PATCH] ITS#9202 limit depth of nested filters
+
+Using a hardcoded limit for now; no reasonable apps
+should ever run into it.
+---
+ servers/slapd/filter.c | 41 ++++++++++++++++++++++++++++++++---------
+ 1 file changed, 32 insertions(+), 9 deletions(-)
+
+diff --git a/servers/slapd/filter.c b/servers/slapd/filter.c
+index 3252cf2a7..ed57bbd7b 100644
+--- a/servers/slapd/filter.c
++++ b/servers/slapd/filter.c
+@@ -37,11 +37,16 @@
+ const Filter *slap_filter_objectClass_pres;
+ const struct berval *slap_filterstr_objectClass_pres;
+ 
++#ifndef SLAPD_MAX_FILTER_DEPTH
++#define SLAPD_MAX_FILTER_DEPTH	5000
++#endif
++
+ static int	get_filter_list(
+ 	Operation *op,
+ 	BerElement *ber,
+ 	Filter **f,
+-	const char **text );
++	const char **text,
++	int depth );
+ 
+ static int	get_ssa(
+ 	Operation *op,
+@@ -80,12 +85,13 @@ filter_destroy( void )
+ 	return;
+ }
+ 
+-int
+-get_filter(
++static int
++get_filter0(
+ 	Operation *op,
+ 	BerElement *ber,
+ 	Filter **filt,
+-	const char **text )
++	const char **text,
++	int depth )
+ {
+ 	ber_tag_t	tag;
+ 	ber_len_t	len;
+@@ -126,6 +132,11 @@ get_filter(
+ 	 *
+ 	 */
+ 
++	if( depth > SLAPD_MAX_FILTER_DEPTH ) {
++		*text = "filter nested too deeply";
++		return SLAPD_DISCONNECT;
++	}
++
+ 	tag = ber_peek_tag( ber, &len );
+ 
+ 	if( tag == LBER_ERROR ) {
+@@ -221,7 +232,7 @@ get_filter(
+ 
+ 	case LDAP_FILTER_AND:
+ 		Debug( LDAP_DEBUG_FILTER, "AND\n", 0, 0, 0 );
+-		err = get_filter_list( op, ber, &f.f_and, text );
++		err = get_filter_list( op, ber, &f.f_and, text, depth+1 );
+ 		if ( err != LDAP_SUCCESS ) {
+ 			break;
+ 		}
+@@ -234,7 +245,7 @@ get_filter(
+ 
+ 	case LDAP_FILTER_OR:
+ 		Debug( LDAP_DEBUG_FILTER, "OR\n", 0, 0, 0 );
+-		err = get_filter_list( op, ber, &f.f_or, text );
++		err = get_filter_list( op, ber, &f.f_or, text, depth+1 );
+ 		if ( err != LDAP_SUCCESS ) {
+ 			break;
+ 		}
+@@ -248,7 +259,7 @@ get_filter(
+ 	case LDAP_FILTER_NOT:
+ 		Debug( LDAP_DEBUG_FILTER, "NOT\n", 0, 0, 0 );
+ 		(void) ber_skip_tag( ber, &len );
+-		err = get_filter( op, ber, &f.f_not, text );
++		err = get_filter0( op, ber, &f.f_not, text, depth+1 );
+ 		if ( err != LDAP_SUCCESS ) {
+ 			break;
+ 		}
+@@ -311,10 +322,22 @@ get_filter(
+ 	return( err );
+ }
+ 
++int
++get_filter(
++	Operation *op,
++	BerElement *ber,
++	Filter **filt,
++	const char **text )
++{
++	return get_filter0( op, ber, filt, text, 0 );
++}
++
++
+ static int
+ get_filter_list( Operation *op, BerElement *ber,
+ 	Filter **f,
+-	const char **text )
++	const char **text,
++	int depth )
+ {
+ 	Filter		**new;
+ 	int		err;
+@@ -328,7 +351,7 @@ get_filter_list( Operation *op, BerElement *ber,
+ 		tag != LBER_DEFAULT;
+ 		tag = ber_next_element( ber, &len, last ) )
+ 	{
+-		err = get_filter( op, ber, new, text );
++		err = get_filter0( op, ber, new, text, depth );
+ 		if ( err != LDAP_SUCCESS )
+ 			return( err );
+ 		new = &(*new)->f_next;
+-- 
+2.26.2
+