ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 210 insertions, 0 deletions

diff --git a/net/rxrpc/security.c b/net/rxrpc/security.c
new file mode 100644
index 000000000..2bfbf2b2b
--- /dev/null
+++ b/net/rxrpc/security.c
@@ -0,0 +1,210 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxRPC security handling
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/udp.h>
+#include <linux/crypto.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <keys/rxrpc-type.h>
+#include "ar-internal.h"
+
+static const struct rxrpc_security *rxrpc_security_types[] = {
+	[RXRPC_SECURITY_NONE]	= &rxrpc_no_security,
+#ifdef CONFIG_RXKAD
+	[RXRPC_SECURITY_RXKAD]	= &rxkad,
+#endif
+#ifdef CONFIG_RXGK
+	[RXRPC_SECURITY_YFS_RXGK] = &rxgk_yfs,
+#endif
+};
+
+int __init rxrpc_init_security(void)
+{
+	int i, ret;
+
+	for (i = 0; i < ARRAY_SIZE(rxrpc_security_types); i++) {
+		if (rxrpc_security_types[i]) {
+			ret = rxrpc_security_types[i]->init();
+			if (ret < 0)
+				goto failed;
+		}
+	}
+
+	return 0;
+
+failed:
+	for (i--; i >= 0; i--)
+		if (rxrpc_security_types[i])
+			rxrpc_security_types[i]->exit();
+	return ret;
+}
+
+void rxrpc_exit_security(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(rxrpc_security_types); i++)
+		if (rxrpc_security_types[i])
+			rxrpc_security_types[i]->exit();
+}
+
+/*
+ * look up an rxrpc security module
+ */
+const struct rxrpc_security *rxrpc_security_lookup(u8 security_index)
+{
+	if (security_index >= ARRAY_SIZE(rxrpc_security_types))
+		return NULL;
+	return rxrpc_security_types[security_index];
+}
+
+/*
+ * Initialise the security on a client call.
+ */
+int rxrpc_init_client_call_security(struct rxrpc_call *call)
+{
+	const struct rxrpc_security *sec = &rxrpc_no_security;
+	struct rxrpc_key_token *token;
+	struct key *key = call->key;
+	int ret;
+
+	if (!key)
+		goto found;
+
+	ret = key_validate(key);
+	if (ret < 0)
+		return ret;
+
+	for (token = key->payload.data[0]; token; token = token->next) {
+		sec = rxrpc_security_lookup(token->security_index);
+		if (sec)
+			goto found;
+	}
+	return -EKEYREJECTED;
+
+found:
+	call->security = sec;
+	call->security_ix = sec->security_index;
+	return 0;
+}
+
+/*
+ * initialise the security on a client connection
+ */
+int rxrpc_init_client_conn_security(struct rxrpc_connection *conn)
+{
+	struct rxrpc_key_token *token;
+	struct key *key = conn->key;
+	int ret = 0;
+
+	_enter("{%d},{%x}", conn->debug_id, key_serial(key));
+
+	for (token = key->payload.data[0]; token; token = token->next) {
+		if (token->security_index == conn->security->security_index)
+			goto found;
+	}
+	return -EKEYREJECTED;
+
+found:
+	mutex_lock(&conn->security_lock);
+	if (conn->state == RXRPC_CONN_CLIENT_UNSECURED) {
+		ret = conn->security->init_connection_security(conn, token);
+		if (ret == 0) {
+			spin_lock_irq(&conn->state_lock);
+			if (conn->state == RXRPC_CONN_CLIENT_UNSECURED)
+				conn->state = RXRPC_CONN_CLIENT;
+			spin_unlock_irq(&conn->state_lock);
+		}
+	}
+	mutex_unlock(&conn->security_lock);
+	return ret;
+}
+
+/*
+ * Set the ops a server connection.
+ */
+const struct rxrpc_security *rxrpc_get_incoming_security(struct rxrpc_sock *rx,
+							 struct sk_buff *skb)
+{
+	const struct rxrpc_security *sec;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+	_enter("");
+
+	sec = rxrpc_security_lookup(sp->hdr.securityIndex);
+	if (!sec) {
+		rxrpc_direct_conn_abort(skb, rxrpc_abort_unsupported_security,
+					RX_INVALID_OPERATION, -EKEYREJECTED);
+		return NULL;
+	}
+
+	if (sp->hdr.securityIndex != RXRPC_SECURITY_NONE &&
+	    !rx->securities) {
+		rxrpc_direct_conn_abort(skb, rxrpc_abort_no_service_key,
+					sec->no_key_abort, -EKEYREJECTED);
+		return NULL;
+	}
+
+	return sec;
+}
+
+/*
+ * Find the security key for a server connection.
+ */
+struct key *rxrpc_look_up_server_security(struct rxrpc_connection *conn,
+					  struct sk_buff *skb,
+					  u32 kvno, u32 enctype)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rxrpc_sock *rx;
+	struct key *key = ERR_PTR(-EKEYREJECTED);
+	key_ref_t kref = NULL;
+	char kdesc[5 + 1 + 3 + 1 + 12 + 1 + 12 + 1];
+	int ret;
+
+	_enter("");
+
+	if (enctype)
+		sprintf(kdesc, "%u:%u:%u:%u",
+			sp->hdr.serviceId, sp->hdr.securityIndex, kvno, enctype);
+	else if (kvno)
+		sprintf(kdesc, "%u:%u:%u",
+			sp->hdr.serviceId, sp->hdr.securityIndex, kvno);
+	else
+		sprintf(kdesc, "%u:%u",
+			sp->hdr.serviceId, sp->hdr.securityIndex);
+
+	read_lock(&conn->local->services_lock);
+
+	rx = conn->local->service;
+	if (!rx)
+		goto out;
+
+	/* look through the service's keyring */
+	kref = keyring_search(make_key_ref(rx->securities, 1UL),
+			      &key_type_rxrpc_s, kdesc, true);
+	if (IS_ERR(kref)) {
+		key = ERR_CAST(kref);
+		goto out;
+	}
+
+	key = key_ref_to_ptr(kref);
+
+	ret = key_validate(key);
+	if (ret < 0) {
+		key_put(key);
+		key = ERR_PTR(ret);
+		goto out;
+	}
+
+out:
+	read_unlock(&conn->local->services_lock);
+	return key;
+}