fix possible privilege escalation when similar master and non-master passdbs are used (#2106232)

Resolves: #2106232

dovecot-2.3.0.1-libxcrypt.patch

@@ -1,11 +0,0 @@
-diff -up dovecot-2.3.0.1/src/auth/mycrypt.c.libxcrypt dovecot-2.3.0.1/src/auth/mycrypt.c
---- dovecot-2.3.0.1/src/auth/mycrypt.c.libxcrypt       2018-02-28 15:28:58.000000000 +0100
-+++ dovecot-2.3.0.1/src/auth/mycrypt.c 2018-03-27 10:57:38.447769201 +0200
-@@ -14,6 +14,7 @@
- #  define _XPG6 /* Some Solaris versions require this, some break with this */
- #endif
- #include <unistd.h>
-+#include <crypt.h>
- 
- #include "mycrypt.h"
- 

dovecot-2.3.19.1-7bad6a24.patch

@@ -0,0 +1,131 @@
+From 7bad6a24160e34bce8f10e73dbbf9e5fbbcd1904 Mon Sep 17 00:00:00 2001
+From: Timo Sirainen <timo.sirainen@open-xchange.com>
+Date: Mon, 9 May 2022 15:23:33 +0300
+Subject: [PATCH] auth: Fix handling passdbs with identical driver/args but
+ different mechanisms/username_filter
+
+The passdb was wrongly deduplicated in this situation, causing wrong
+mechanisms or username_filter setting to be used. This would be a rather
+unlikely configuration though.
+
+Fixed by moving mechanisms and username_filter from struct passdb_module
+to struct auth_passdb, which is where they should have been in the first
+place.
+---
+ src/auth/auth-request.c |  6 +++---
+ src/auth/auth.c         | 18 ++++++++++++++++++
+ src/auth/auth.h         |  5 +++++
+ src/auth/passdb.c       | 15 ++-------------
+ src/auth/passdb.h       |  4 ----
+ 5 files changed, 28 insertions(+), 20 deletions(-)
+
+diff --git a/src/auth/auth-request.c b/src/auth/auth-request.c
+index cd08b1fa02..0ca29f3674 100644
+--- a/src/auth/auth-request.c
++++ b/src/auth/auth-request.c
+@@ -534,8 +534,8 @@ auth_request_want_skip_passdb(struct auth_request *request,
+ 			      struct auth_passdb *passdb)
+ {
+ 	/* if mechanism is not supported, skip */
+-	const char *const *mechs = passdb->passdb->mechanisms;
+-	const char *const *username_filter = passdb->passdb->username_filter;
++	const char *const *mechs = passdb->mechanisms;
++	const char *const *username_filter = passdb->username_filter;
+ 	const char *username;
+ 
+ 	username = request->fields.user;
+@@ -548,7 +548,7 @@ auth_request_want_skip_passdb(struct auth_request *request,
+ 		return TRUE;
+ 	}
+ 
+-	if (passdb->passdb->username_filter != NULL &&
++	if (passdb->username_filter != NULL &&
+ 	    !auth_request_username_accepted(username_filter, username)) {
+ 		auth_request_log_debug(request,
+ 				       request->mech != NULL ? AUTH_SUBSYS_MECH
+diff --git a/src/auth/auth.c b/src/auth/auth.c
+index f2f3fda20c..9f6c4ba60c 100644
+--- a/src/auth/auth.c
++++ b/src/auth/auth.c
+@@ -99,6 +99,24 @@ auth_passdb_preinit(struct auth *auth, const struct auth_passdb_settings *set,
+ 	auth_passdb->override_fields_tmpl =
+ 		passdb_template_build(auth->pool, set->override_fields);
+ 
++	if (*set->mechanisms == '\0') {
++		auth_passdb->mechanisms = NULL;
++	} else if (strcasecmp(set->mechanisms, "none") == 0) {
++		auth_passdb->mechanisms = (const char *const[]){ NULL };
++	} else {
++		auth_passdb->mechanisms =
++			(const char *const *)p_strsplit_spaces(auth->pool,
++				set->mechanisms, " ,");
++	}
++
++	if (*set->username_filter == '\0') {
++		auth_passdb->username_filter = NULL;
++	} else {
++		auth_passdb->username_filter =
++			(const char *const *)p_strsplit_spaces(auth->pool,
++				set->username_filter, " ,");
++	}
++
+ 	/* for backwards compatibility: */
+ 	if (set->pass)
+ 		auth_passdb->result_success = AUTH_DB_RULE_CONTINUE;
+diff --git a/src/auth/auth.h b/src/auth/auth.h
+index f700e29d5c..460a179765 100644
+--- a/src/auth/auth.h
++++ b/src/auth/auth.h
+@@ -41,6 +41,11 @@ struct auth_passdb {
+ 	struct passdb_template *default_fields_tmpl;
+ 	struct passdb_template *override_fields_tmpl;
+ 
++	/* Supported authentication mechanisms, NULL is all, {NULL} is none */
++	const char *const *mechanisms;
++	/* Username filter, NULL is no filter */
++	const char *const *username_filter;
++
+ 	enum auth_passdb_skip skip;
+ 	enum auth_db_rule result_success;
+ 	enum auth_db_rule result_failure;
+diff --git a/src/auth/passdb.c b/src/auth/passdb.c
+index eb4ac8ae82..f5eed1af4f 100644
+--- a/src/auth/passdb.c
++++ b/src/auth/passdb.c
+@@ -224,19 +224,8 @@ passdb_preinit(pool_t pool, const struct auth_passdb_settings *set)
+ 	passdb->id = ++auth_passdb_id;
+ 	passdb->iface = *iface;
+ 	passdb->args = p_strdup(pool, set->args);
+-	if (*set->mechanisms == '\0') {
+-		passdb->mechanisms = NULL;
+-	} else if (strcasecmp(set->mechanisms, "none") == 0) {
+-		passdb->mechanisms = (const char *const[]){NULL};
+-	} else {
+-		passdb->mechanisms = (const char* const*)p_strsplit_spaces(pool, set->mechanisms, " ,");
+-	}
+-
+-	if (*set->username_filter == '\0') {
+-		passdb->username_filter = NULL;
+-	} else {
+-		passdb->username_filter = (const char* const*)p_strsplit_spaces(pool, set->username_filter, " ,");
+-	}
++	/* NOTE: if anything else than driver & args are added here,
++	   passdb_find() also needs to be updated. */
+ 	array_push_back(&passdb_modules, &passdb);
+ 	return passdb;
+ }
+diff --git a/src/auth/passdb.h b/src/auth/passdb.h
+index 2e95328e5c..e466a9fdb6 100644
+--- a/src/auth/passdb.h
++++ b/src/auth/passdb.h
+@@ -63,10 +63,6 @@ struct passdb_module {
+ 	/* Default password scheme for this module.
+ 	   If default_cache_key is set, must not be NULL. */
+ 	const char *default_pass_scheme;
+-	/* Supported authentication mechanisms, NULL is all, [NULL] is none*/
+-	const char *const *mechanisms;
+-	/* Username filter, NULL is no filter */
+-	const char *const *username_filter;
+ 
+ 	/* If blocking is set to TRUE, use child processes to access
+ 	   this passdb. */

dovecot.spec

@@ -6,7 +6,7 @@ Name: dovecot
 Epoch: 1
 Version: 2.3.16
 %global prever %{nil}
-Release: 6%{?dist}
+Release: 7%{?dist}
 #dovecot itself is MIT, a few sources are PD, pigeonhole is LGPLv2
 License: MIT and LGPLv2
 
@@ -34,7 +34,6 @@ Patch6: dovecot-2.1.10-waitonline.patch
 
 Patch8: dovecot-2.2.20-initbysystemd.patch
 Patch9: dovecot-2.2.22-systemd_w_protectsystem.patch
-Patch10: dovecot-2.3.0.1-libxcrypt.patch
 Patch15: dovecot-2.3.11-bigkey.patch
 
 # do not use own implementation of HMAC, use OpenSSL for certification purposes
@@ -49,6 +48,8 @@ Patch18: dovecot-2.3.15-fixvalcond.patch
 Patch19: dovecot-2.3.15-valbasherr.patch
 Patch20: dovecot-2.3.16-ftbfsbigend.patch
 
+# from upstream, for <= 2.3.19.1, rhbz#2106232
+Patch21: dovecot-2.3.19.1-7bad6a24.patch
 
 BuildRequires: gcc, gcc-c++, openssl-devel, pam-devel, zlib-devel, bzip2-devel, libcap-devel
 BuildRequires: libtool, autoconf, automake, pkgconfig
@@ -144,6 +145,7 @@ This package provides the development files for dovecot.
 %patch18 -p1 -b .fixvalcond
 %patch19 -p1 -b .valbasherr
 %patch20 -p1 -b .ftbfsbigend
+%patch21 -p1 -b .7bad6a24
 cp run-test-valgrind.supp dovecot-2.3-pigeonhole-%{pigeonholever}/
 # valgrind would fail with shell wrapper
 echo "testsuite" >dovecot-2.3-pigeonhole-%{pigeonholever}/run-test-valgrind.exclude
@@ -466,6 +468,9 @@ make check
 %{_libdir}/%{name}/dict/libdriver_pgsql.so
 
 %changelog
+* Tue Jul 12 2022 Michal Hlavinka <mhlavink@redhat.com> - 1:2.3.16-7
+- fix possible privilege escalation when similar master and non-master passdbs are used (#2106232)
+
 * Wed Jul 06 2022 Michal Hlavinka <mhlavink@redhat.com> - 1:2.3.16-6
 - fix possible nonzero return value of postinst script(#2053368)