From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/security/keys/request_key_auth.c | 74 ++++++++++++++++++++----------------
1 files changed, 41 insertions(+), 33 deletions(-)
diff --git a/kernel/security/keys/request_key_auth.c b/kernel/security/keys/request_key_auth.c
index 13ac3b1..41e9735 100644
--- a/kernel/security/keys/request_key_auth.c
+++ b/kernel/security/keys/request_key_auth.c
@@ -1,17 +1,12 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/* Request key authorisation token key definition.
*
* Copyright (C) 2005 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
- * This program 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
- * 2 of the License, or (at your option) any later version.
- *
* See Documentation/security/keys/request-key.rst
*/
-#include <linux/module.h>
#include <linux/sched.h>
#include <linux/err.h>
#include <linux/seq_file.h>
@@ -59,7 +54,7 @@
static int request_key_auth_instantiate(struct key *key,
struct key_preparsed_payload *prep)
{
- key->payload.data[0] = (struct request_key_auth *)prep->data;
+ rcu_assign_keypointer(key, (struct request_key_auth *)prep->data);
return 0;
}
@@ -69,7 +64,7 @@
static void request_key_auth_describe(const struct key *key,
struct seq_file *m)
{
- struct request_key_auth *rka = get_request_key_auth(key);
+ struct request_key_auth *rka = dereference_key_rcu(key);
if (!rka)
return;
@@ -87,7 +82,7 @@
static long request_key_auth_read(const struct key *key,
char *buffer, size_t buflen)
{
- struct request_key_auth *rka = get_request_key_auth(key);
+ struct request_key_auth *rka = dereference_key_locked(key);
size_t datalen;
long ret;
@@ -108,23 +103,6 @@
return ret;
}
-/*
- * Handle revocation of an authorisation token key.
- *
- * Called with the key sem write-locked.
- */
-static void request_key_auth_revoke(struct key *key)
-{
- struct request_key_auth *rka = get_request_key_auth(key);
-
- kenter("{%d}", key->serial);
-
- if (rka->cred) {
- put_cred(rka->cred);
- rka->cred = NULL;
- }
-}
-
static void free_request_key_auth(struct request_key_auth *rka)
{
if (!rka)
@@ -138,15 +116,42 @@
}
/*
+ * Dispose of the request_key_auth record under RCU conditions
+ */
+static void request_key_auth_rcu_disposal(struct rcu_head *rcu)
+{
+ struct request_key_auth *rka =
+ container_of(rcu, struct request_key_auth, rcu);
+
+ free_request_key_auth(rka);
+}
+
+/*
+ * Handle revocation of an authorisation token key.
+ *
+ * Called with the key sem write-locked.
+ */
+static void request_key_auth_revoke(struct key *key)
+{
+ struct request_key_auth *rka = dereference_key_locked(key);
+
+ kenter("{%d}", key->serial);
+ rcu_assign_keypointer(key, NULL);
+ call_rcu(&rka->rcu, request_key_auth_rcu_disposal);
+}
+
+/*
* Destroy an instantiation authorisation token key.
*/
static void request_key_auth_destroy(struct key *key)
{
- struct request_key_auth *rka = get_request_key_auth(key);
+ struct request_key_auth *rka = rcu_access_pointer(key->payload.rcu_data0);
kenter("{%d}", key->serial);
-
- free_request_key_auth(rka);
+ if (rka) {
+ rcu_assign_keypointer(key, NULL);
+ call_rcu(&rka->rcu, request_key_auth_rcu_disposal);
+ }
}
/*
@@ -158,7 +163,7 @@
struct key *dest_keyring)
{
struct request_key_auth *rka, *irka;
- const struct cred *cred = current->cred;
+ const struct cred *cred = current_cred();
struct key *authkey = NULL;
char desc[20];
int ret = -ENOMEM;
@@ -210,7 +215,7 @@
authkey = key_alloc(&key_type_request_key_auth, desc,
cred->fsuid, cred->fsgid, cred,
- KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH |
+ KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH | KEY_POS_LINK |
KEY_USR_VIEW, KEY_ALLOC_NOT_IN_QUOTA, NULL);
if (IS_ERR(authkey)) {
ret = PTR_ERR(authkey);
@@ -248,14 +253,17 @@
.match_data.cmp = key_default_cmp,
.match_data.raw_data = description,
.match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
- .flags = KEYRING_SEARCH_DO_STATE_CHECK,
+ .flags = (KEYRING_SEARCH_DO_STATE_CHECK |
+ KEYRING_SEARCH_RECURSE),
};
struct key *authkey;
key_ref_t authkey_ref;
ctx.index_key.desc_len = sprintf(description, "%x", target_id);
- authkey_ref = search_process_keyrings(&ctx);
+ rcu_read_lock();
+ authkey_ref = search_process_keyrings_rcu(&ctx);
+ rcu_read_unlock();
if (IS_ERR(authkey_ref)) {
authkey = ERR_CAST(authkey_ref);
--
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