File gnutls-CVE-2025-9820.patch of Package gnutls.41790
From 1d56f96f6ab5034d677136b9d50b5a75dff0faf5 Mon Sep 17 00:00:00 2001
From: Daiki Ueno <ueno@gnu.org>
Date: Tue, 18 Nov 2025 13:17:55 +0900
Subject: [PATCH] pkcs11: avoid stack overwrite when initializing a token
If gnutls_pkcs11_token_init is called with label longer than 32
characters, the internal storage used to blank-fill it would
overflow. This adds a guard to prevent that.
Signed-off-by: Daiki Ueno <ueno@gnu.org>
---
.gitignore | 2 +
NEWS | 4 +
lib/pkcs11_write.c | 5 +-
tests/Makefile.am | 2 +-
tests/pkcs11/long-label.c | 164 ++++++++++++++++++++++++++++++++++++++
5 files changed, 174 insertions(+), 3 deletions(-)
create mode 100644 tests/pkcs11/long-label.c
Index: gnutls-3.6.7/lib/pkcs11_write.c
===================================================================
--- gnutls-3.6.7.orig/lib/pkcs11_write.c
+++ gnutls-3.6.7/lib/pkcs11_write.c
@@ -28,6 +28,7 @@
#include "pkcs11x.h"
#include <x509/common.h>
#include "pk.h"
+#include "minmax.h"
static const ck_bool_t tval = 1;
static const ck_bool_t fval = 0;
@@ -1190,7 +1191,7 @@ int gnutls_pkcs11_delete_url(const char
* gnutls_pkcs11_token_init:
* @token_url: A PKCS #11 URL specifying a token
* @so_pin: Security Officer's PIN
- * @label: A name to be used for the token
+ * @label: A name to be used for the token, at most 32 characters
*
* This function will initialize (format) a token. If the token is
* at a factory defaults state the security officer's PIN given will be
@@ -1229,7 +1230,7 @@ gnutls_pkcs11_token_init(const char *tok
/* so it seems memset has other uses than zeroing! */
memset(flabel, ' ', sizeof(flabel));
if (label != NULL)
- memcpy(flabel, label, strlen(label));
+ memcpy(flabel, label, MIN(sizeof(flabel), strlen(label)));
rv = pkcs11_init_token(module, slot, (uint8_t *) so_pin,
strlen(so_pin), (uint8_t *) flabel);
Index: gnutls-3.6.7/tests/Makefile.am
===================================================================
--- gnutls-3.6.7.orig/tests/Makefile.am
+++ gnutls-3.6.7/tests/Makefile.am
@@ -177,7 +177,7 @@ ctests += mini-record-2 simple gnutls_hm
fallback-scsv pkcs8-key-decode urls dtls-rehandshake-cert \
key-usage-rsa key-usage-ecdhe-rsa mini-session-verify-function auto-verify \
record-timeouts mini-dtls-hello-verify-48 set-default-prio \
- tls12-anon-upgrade global-init-override tlsext-decoding rsa-psk-cb \
+ tls12-anon-upgrade global-init-override pkcs11/long-label tlsext-decoding rsa-psk-cb \
rehandshake-switch-cert rehandshake-switch-cert-allow rehandshake-switch-cert-client \
rehandshake-switch-cert-client-allow handshake-versions dtls-handshake-versions \
dtls-max-record tls12-max-record alpn-server-prec ocsp-filename-memleak \
Index: gnutls-3.6.7/tests/pkcs11/long-label.c
===================================================================
--- /dev/null
+++ gnutls-3.6.7/tests/pkcs11/long-label.c
@@ -0,0 +1,164 @@
+/*
+ * Copyright (C) 2025 Red Hat, Inc.
+ *
+ * Author: Daiki Ueno
+ *
+ * This file is part of GnuTLS.
+ *
+ * GnuTLS is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuTLS is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#if defined(_WIN32)
+
+int main(void)
+{
+ exit(77);
+}
+
+#else
+
+#include <string.h>
+#include <unistd.h>
+#include <gnutls/gnutls.h>
+
+#include "cert-common.h"
+#include "pkcs11/softhsm.h"
+#include "utils.h"
+
+/* This program tests that a token can be initialized with
+ * a label longer than 32 characters.
+ */
+
+static void tls_log_func(int level, const char *str)
+{
+ fprintf(stderr, "server|<%d>| %s", level, str);
+}
+
+#define PIN "1234"
+
+#define CONFIG_NAME "softhsm-long-label"
+#define CONFIG CONFIG_NAME ".config"
+
+static int pin_func(void *userdata, int attempt, const char *url,
+ const char *label, unsigned flags, char *pin,
+ size_t pin_max)
+{
+ if (attempt == 0) {
+ strcpy(pin, PIN);
+ return 0;
+ }
+ return -1;
+}
+
+static void test(const char *provider)
+{
+ int ret;
+ size_t i;
+
+ gnutls_pkcs11_init(GNUTLS_PKCS11_FLAG_MANUAL, NULL);
+
+ success("test with %s\n", provider);
+
+ if (debug) {
+ gnutls_global_set_log_function(tls_log_func);
+ gnutls_global_set_log_level(4711);
+ }
+
+ /* point to SoftHSM token that libpkcs11mock4.so internally uses */
+ setenv(SOFTHSM_ENV, CONFIG, 1);
+
+ gnutls_pkcs11_set_pin_function(pin_func, NULL);
+
+ ret = gnutls_pkcs11_add_provider(provider, "trusted");
+ if (ret != 0) {
+ fail("gnutls_pkcs11_add_provider: %s\n", gnutls_strerror(ret));
+ }
+
+ /* initialize softhsm token */
+ ret = gnutls_pkcs11_token_init(
+ SOFTHSM_URL, PIN,
+ "this is a very long label whose length exceeds 32");
+ if (ret < 0) {
+ fail("gnutls_pkcs11_token_init: %s\n", gnutls_strerror(ret));
+ }
+
+ for (i = 0;; i++) {
+ char *url = NULL;
+
+ ret = gnutls_pkcs11_token_get_url(i, 0, &url);
+ if (ret < 0)
+ break;
+ if (strstr(url,
+ "token=this%20is%20a%20very%20long%20label%20whose"))
+ break;
+ }
+ if (ret < 0)
+ fail("gnutls_pkcs11_token_get_url: %s\n", gnutls_strerror(ret));
+
+ gnutls_pkcs11_deinit();
+}
+
+void doit(void)
+{
+ const char *bin;
+ const char *lib;
+ char buf[128];
+
+ if (gnutls_fips140_mode_enabled())
+ exit(77);
+
+ /* this must be called once in the program */
+ global_init();
+
+ /* we call gnutls_pkcs11_init manually */
+ gnutls_pkcs11_deinit();
+
+ /* check if softhsm module is loadable */
+ lib = softhsm_lib();
+
+ /* initialize SoftHSM token that libpkcs11mock4.so internally uses */
+ bin = softhsm_bin();
+
+ set_softhsm_conf(CONFIG);
+ snprintf(buf, sizeof(buf),
+ "%s --init-token --slot 0 --label test --so-pin " PIN
+ " --pin " PIN,
+ bin);
+ system(buf);
+
+ test(lib);
+
+ lib = getenv("P11MOCKLIB4");
+ if (lib == NULL) {
+ fail("P11MOCKLIB4 is not set\n");
+ }
+
+ set_softhsm_conf(CONFIG);
+ snprintf(buf, sizeof(buf),
+ "%s --init-token --slot 0 --label test --so-pin " PIN
+ " --pin " PIN,
+ bin);
+ system(buf);
+
+ test(lib);
+}
+#endif /* _WIN32 */
