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, 457 insertions, 0 deletions

diff --git a/net/handshake/tlshd.c b/net/handshake/tlshd.c
new file mode 100644
index 000000000..7567150c2
--- /dev/null
+++ b/net/handshake/tlshd.c
@@ -0,0 +1,457 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Establish a TLS session for a kernel socket consumer
+ * using the tlshd user space handler.
+ *
+ * Author: Chuck Lever <chuck.lever@oracle.com>
+ *
+ * Copyright (c) 2021-2023, Oracle and/or its affiliates.
+ */
+
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/key.h>
+
+#include <net/sock.h>
+#include <net/handshake.h>
+#include <net/genetlink.h>
+#include <net/tls_prot.h>
+
+#include <uapi/linux/keyctl.h>
+#include <uapi/linux/handshake.h>
+#include "handshake.h"
+
+struct tls_handshake_req {
+	void			(*th_consumer_done)(void *data, int status,
+						    key_serial_t peerid);
+	void			*th_consumer_data;
+
+	int			th_type;
+	unsigned int		th_timeout_ms;
+	int			th_auth_mode;
+	const char		*th_peername;
+	key_serial_t		th_keyring;
+	key_serial_t		th_certificate;
+	key_serial_t		th_privkey;
+
+	unsigned int		th_num_peerids;
+	key_serial_t		th_peerid[5];
+};
+
+static struct tls_handshake_req *
+tls_handshake_req_init(struct handshake_req *req,
+		       const struct tls_handshake_args *args)
+{
+	struct tls_handshake_req *treq = handshake_req_private(req);
+
+	treq->th_timeout_ms = args->ta_timeout_ms;
+	treq->th_consumer_done = args->ta_done;
+	treq->th_consumer_data = args->ta_data;
+	treq->th_peername = args->ta_peername;
+	treq->th_keyring = args->ta_keyring;
+	treq->th_num_peerids = 0;
+	treq->th_certificate = TLS_NO_CERT;
+	treq->th_privkey = TLS_NO_PRIVKEY;
+	return treq;
+}
+
+static void tls_handshake_remote_peerids(struct tls_handshake_req *treq,
+					 struct genl_info *info)
+{
+	struct nlattr *head = nlmsg_attrdata(info->nlhdr, GENL_HDRLEN);
+	int rem, len = nlmsg_attrlen(info->nlhdr, GENL_HDRLEN);
+	struct nlattr *nla;
+	unsigned int i;
+
+	i = 0;
+	nla_for_each_attr(nla, head, len, rem) {
+		if (nla_type(nla) == HANDSHAKE_A_DONE_REMOTE_AUTH)
+			i++;
+	}
+	if (!i)
+		return;
+	treq->th_num_peerids = min_t(unsigned int, i,
+				     ARRAY_SIZE(treq->th_peerid));
+
+	i = 0;
+	nla_for_each_attr(nla, head, len, rem) {
+		if (nla_type(nla) == HANDSHAKE_A_DONE_REMOTE_AUTH)
+			treq->th_peerid[i++] = nla_get_u32(nla);
+		if (i >= treq->th_num_peerids)
+			break;
+	}
+}
+
+/**
+ * tls_handshake_done - callback to handle a CMD_DONE request
+ * @req: socket on which the handshake was performed
+ * @status: session status code
+ * @info: full results of session establishment
+ *
+ */
+static void tls_handshake_done(struct handshake_req *req,
+			       int status, struct genl_info *info)
+{
+	struct tls_handshake_req *treq = handshake_req_private(req);
+
+	treq->th_peerid[0] = TLS_NO_PEERID;
+	if (info)
+		tls_handshake_remote_peerids(treq, info);
+
+	if (!status)
+		set_bit(HANDSHAKE_F_REQ_SESSION, &req->hr_flags);
+
+	treq->th_consumer_done(treq->th_consumer_data, status,
+			       treq->th_peerid[0]);
+}
+
+#if IS_ENABLED(CONFIG_KEYS)
+static int tls_handshake_private_keyring(struct tls_handshake_req *treq)
+{
+	key_ref_t process_keyring_ref, keyring_ref;
+	int ret;
+
+	if (treq->th_keyring == TLS_NO_KEYRING)
+		return 0;
+
+	process_keyring_ref = lookup_user_key(KEY_SPEC_PROCESS_KEYRING,
+					      KEY_LOOKUP_CREATE,
+					      KEY_NEED_WRITE);
+	if (IS_ERR(process_keyring_ref)) {
+		ret = PTR_ERR(process_keyring_ref);
+		goto out;
+	}
+
+	keyring_ref = lookup_user_key(treq->th_keyring, KEY_LOOKUP_CREATE,
+				      KEY_NEED_LINK);
+	if (IS_ERR(keyring_ref)) {
+		ret = PTR_ERR(keyring_ref);
+		goto out_put_key;
+	}
+
+	ret = key_link(key_ref_to_ptr(process_keyring_ref),
+		       key_ref_to_ptr(keyring_ref));
+
+	key_ref_put(keyring_ref);
+out_put_key:
+	key_ref_put(process_keyring_ref);
+out:
+	return ret;
+}
+#else
+static int tls_handshake_private_keyring(struct tls_handshake_req *treq)
+{
+	return 0;
+}
+#endif
+
+static int tls_handshake_put_peer_identity(struct sk_buff *msg,
+					   struct tls_handshake_req *treq)
+{
+	unsigned int i;
+
+	for (i = 0; i < treq->th_num_peerids; i++)
+		if (nla_put_u32(msg, HANDSHAKE_A_ACCEPT_PEER_IDENTITY,
+				treq->th_peerid[i]) < 0)
+			return -EMSGSIZE;
+	return 0;
+}
+
+static int tls_handshake_put_certificate(struct sk_buff *msg,
+					 struct tls_handshake_req *treq)
+{
+	struct nlattr *entry_attr;
+
+	if (treq->th_certificate == TLS_NO_CERT &&
+	    treq->th_privkey == TLS_NO_PRIVKEY)
+		return 0;
+
+	entry_attr = nla_nest_start(msg, HANDSHAKE_A_ACCEPT_CERTIFICATE);
+	if (!entry_attr)
+		return -EMSGSIZE;
+
+	if (nla_put_s32(msg, HANDSHAKE_A_X509_CERT,
+			treq->th_certificate) ||
+	    nla_put_s32(msg, HANDSHAKE_A_X509_PRIVKEY,
+			treq->th_privkey)) {
+		nla_nest_cancel(msg, entry_attr);
+		return -EMSGSIZE;
+	}
+
+	nla_nest_end(msg, entry_attr);
+	return 0;
+}
+
+/**
+ * tls_handshake_accept - callback to construct a CMD_ACCEPT response
+ * @req: handshake parameters to return
+ * @info: generic netlink message context
+ * @fd: file descriptor to be returned
+ *
+ * Returns zero on success, or a negative errno on failure.
+ */
+static int tls_handshake_accept(struct handshake_req *req,
+				struct genl_info *info, int fd)
+{
+	struct tls_handshake_req *treq = handshake_req_private(req);
+	struct nlmsghdr *hdr;
+	struct sk_buff *msg;
+	int ret;
+
+	ret = tls_handshake_private_keyring(treq);
+	if (ret < 0)
+		goto out;
+
+	ret = -ENOMEM;
+	msg = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!msg)
+		goto out;
+	hdr = handshake_genl_put(msg, info);
+	if (!hdr)
+		goto out_cancel;
+
+	ret = nla_put_s32(msg, HANDSHAKE_A_ACCEPT_SOCKFD, fd);
+	if (ret < 0)
+		goto out_cancel;
+	ret = nla_put_u32(msg, HANDSHAKE_A_ACCEPT_MESSAGE_TYPE, treq->th_type);
+	if (ret < 0)
+		goto out_cancel;
+	if (treq->th_peername) {
+		ret = nla_put_string(msg, HANDSHAKE_A_ACCEPT_PEERNAME,
+				     treq->th_peername);
+		if (ret < 0)
+			goto out_cancel;
+	}
+	if (treq->th_timeout_ms) {
+		ret = nla_put_u32(msg, HANDSHAKE_A_ACCEPT_TIMEOUT, treq->th_timeout_ms);
+		if (ret < 0)
+			goto out_cancel;
+	}
+	if (treq->th_keyring) {
+		ret = nla_put_u32(msg, HANDSHAKE_A_ACCEPT_KEYRING,
+				  treq->th_keyring);
+		if (ret < 0)
+			goto out_cancel;
+	}
+
+	ret = nla_put_u32(msg, HANDSHAKE_A_ACCEPT_AUTH_MODE,
+			  treq->th_auth_mode);
+	if (ret < 0)
+		goto out_cancel;
+	switch (treq->th_auth_mode) {
+	case HANDSHAKE_AUTH_PSK:
+		ret = tls_handshake_put_peer_identity(msg, treq);
+		if (ret < 0)
+			goto out_cancel;
+		break;
+	case HANDSHAKE_AUTH_X509:
+		ret = tls_handshake_put_certificate(msg, treq);
+		if (ret < 0)
+			goto out_cancel;
+		break;
+	}
+
+	genlmsg_end(msg, hdr);
+	return genlmsg_reply(msg, info);
+
+out_cancel:
+	genlmsg_cancel(msg, hdr);
+	nlmsg_free(msg);
+out:
+	return ret;
+}
+
+static const struct handshake_proto tls_handshake_proto = {
+	.hp_handler_class	= HANDSHAKE_HANDLER_CLASS_TLSHD,
+	.hp_privsize		= sizeof(struct tls_handshake_req),
+	.hp_flags		= BIT(HANDSHAKE_F_PROTO_NOTIFY),
+
+	.hp_accept		= tls_handshake_accept,
+	.hp_done		= tls_handshake_done,
+};
+
+/**
+ * tls_client_hello_anon - request an anonymous TLS handshake on a socket
+ * @args: socket and handshake parameters for this request
+ * @flags: memory allocation control flags
+ *
+ * Return values:
+ *   %0: Handshake request enqueue; ->done will be called when complete
+ *   %-ESRCH: No user agent is available
+ *   %-ENOMEM: Memory allocation failed
+ */
+int tls_client_hello_anon(const struct tls_handshake_args *args, gfp_t flags)
+{
+	struct tls_handshake_req *treq;
+	struct handshake_req *req;
+
+	req = handshake_req_alloc(&tls_handshake_proto, flags);
+	if (!req)
+		return -ENOMEM;
+	treq = tls_handshake_req_init(req, args);
+	treq->th_type = HANDSHAKE_MSG_TYPE_CLIENTHELLO;
+	treq->th_auth_mode = HANDSHAKE_AUTH_UNAUTH;
+
+	return handshake_req_submit(args->ta_sock, req, flags);
+}
+EXPORT_SYMBOL(tls_client_hello_anon);
+
+/**
+ * tls_client_hello_x509 - request an x.509-based TLS handshake on a socket
+ * @args: socket and handshake parameters for this request
+ * @flags: memory allocation control flags
+ *
+ * Return values:
+ *   %0: Handshake request enqueue; ->done will be called when complete
+ *   %-ESRCH: No user agent is available
+ *   %-ENOMEM: Memory allocation failed
+ */
+int tls_client_hello_x509(const struct tls_handshake_args *args, gfp_t flags)
+{
+	struct tls_handshake_req *treq;
+	struct handshake_req *req;
+
+	req = handshake_req_alloc(&tls_handshake_proto, flags);
+	if (!req)
+		return -ENOMEM;
+	treq = tls_handshake_req_init(req, args);
+	treq->th_type = HANDSHAKE_MSG_TYPE_CLIENTHELLO;
+	treq->th_auth_mode = HANDSHAKE_AUTH_X509;
+	treq->th_certificate = args->ta_my_cert;
+	treq->th_privkey = args->ta_my_privkey;
+
+	return handshake_req_submit(args->ta_sock, req, flags);
+}
+EXPORT_SYMBOL(tls_client_hello_x509);
+
+/**
+ * tls_client_hello_psk - request a PSK-based TLS handshake on a socket
+ * @args: socket and handshake parameters for this request
+ * @flags: memory allocation control flags
+ *
+ * Return values:
+ *   %0: Handshake request enqueue; ->done will be called when complete
+ *   %-EINVAL: Wrong number of local peer IDs
+ *   %-ESRCH: No user agent is available
+ *   %-ENOMEM: Memory allocation failed
+ */
+int tls_client_hello_psk(const struct tls_handshake_args *args, gfp_t flags)
+{
+	struct tls_handshake_req *treq;
+	struct handshake_req *req;
+	unsigned int i;
+
+	if (!args->ta_num_peerids ||
+	    args->ta_num_peerids > ARRAY_SIZE(treq->th_peerid))
+		return -EINVAL;
+
+	req = handshake_req_alloc(&tls_handshake_proto, flags);
+	if (!req)
+		return -ENOMEM;
+	treq = tls_handshake_req_init(req, args);
+	treq->th_type = HANDSHAKE_MSG_TYPE_CLIENTHELLO;
+	treq->th_auth_mode = HANDSHAKE_AUTH_PSK;
+	treq->th_num_peerids = args->ta_num_peerids;
+	for (i = 0; i < args->ta_num_peerids; i++)
+		treq->th_peerid[i] = args->ta_my_peerids[i];
+
+	return handshake_req_submit(args->ta_sock, req, flags);
+}
+EXPORT_SYMBOL(tls_client_hello_psk);
+
+/**
+ * tls_server_hello_x509 - request a server TLS handshake on a socket
+ * @args: socket and handshake parameters for this request
+ * @flags: memory allocation control flags
+ *
+ * Return values:
+ *   %0: Handshake request enqueue; ->done will be called when complete
+ *   %-ESRCH: No user agent is available
+ *   %-ENOMEM: Memory allocation failed
+ */
+int tls_server_hello_x509(const struct tls_handshake_args *args, gfp_t flags)
+{
+	struct tls_handshake_req *treq;
+	struct handshake_req *req;
+
+	req = handshake_req_alloc(&tls_handshake_proto, flags);
+	if (!req)
+		return -ENOMEM;
+	treq = tls_handshake_req_init(req, args);
+	treq->th_type = HANDSHAKE_MSG_TYPE_SERVERHELLO;
+	treq->th_auth_mode = HANDSHAKE_AUTH_X509;
+	treq->th_certificate = args->ta_my_cert;
+	treq->th_privkey = args->ta_my_privkey;
+
+	return handshake_req_submit(args->ta_sock, req, flags);
+}
+EXPORT_SYMBOL(tls_server_hello_x509);
+
+/**
+ * tls_server_hello_psk - request a server TLS handshake on a socket
+ * @args: socket and handshake parameters for this request
+ * @flags: memory allocation control flags
+ *
+ * Return values:
+ *   %0: Handshake request enqueue; ->done will be called when complete
+ *   %-ESRCH: No user agent is available
+ *   %-ENOMEM: Memory allocation failed
+ */
+int tls_server_hello_psk(const struct tls_handshake_args *args, gfp_t flags)
+{
+	struct tls_handshake_req *treq;
+	struct handshake_req *req;
+
+	req = handshake_req_alloc(&tls_handshake_proto, flags);
+	if (!req)
+		return -ENOMEM;
+	treq = tls_handshake_req_init(req, args);
+	treq->th_type = HANDSHAKE_MSG_TYPE_SERVERHELLO;
+	treq->th_auth_mode = HANDSHAKE_AUTH_PSK;
+	treq->th_num_peerids = 1;
+	treq->th_peerid[0] = args->ta_my_peerids[0];
+
+	return handshake_req_submit(args->ta_sock, req, flags);
+}
+EXPORT_SYMBOL(tls_server_hello_psk);
+
+/**
+ * tls_handshake_cancel - cancel a pending handshake
+ * @sk: socket on which there is an ongoing handshake
+ *
+ * Request cancellation races with request completion. To determine
+ * who won, callers examine the return value from this function.
+ *
+ * Context: May be called from process or softirq context.
+ *
+ * Return values:
+ *   %true - Uncompleted handshake request was canceled
+ *   %false - Handshake request already completed or not found
+ */
+bool tls_handshake_cancel(struct sock *sk)
+{
+	return handshake_req_cancel(sk);
+}
+EXPORT_SYMBOL(tls_handshake_cancel);
+
+/**
+ * tls_handshake_close - send a Closure alert
+ * @sock: an open socket
+ *
+ */
+void tls_handshake_close(struct socket *sock)
+{
+	struct handshake_req *req;
+
+	req = handshake_req_hash_lookup(sock->sk);
+	if (!req)
+		return;
+	if (!test_and_clear_bit(HANDSHAKE_F_REQ_SESSION, &req->hr_flags))
+		return;
+	tls_alert_send(sock, TLS_ALERT_LEVEL_WARNING,
+		       TLS_ALERT_DESC_CLOSE_NOTIFY);
+}
+EXPORT_SYMBOL(tls_handshake_close);