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, 254 insertions, 0 deletions

diff --git a/crypto/algboss.c b/crypto/algboss.c
new file mode 100644
index 000000000..8b936cae6
--- /dev/null
+++ b/crypto/algboss.c
@@ -0,0 +1,254 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Create default crypto algorithm instances.
+ *
+ * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+
+#include <crypto/internal/aead.h>
+#include <linux/completion.h>
+#include <linux/ctype.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/rtnetlink.h>
+#include <linux/sched/signal.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include "internal.h"
+
+struct cryptomgr_param {
+	struct rtattr *tb[CRYPTO_MAX_ATTRS + 2];
+
+	struct {
+		struct rtattr attr;
+		struct crypto_attr_type data;
+	} type;
+
+	struct {
+		struct rtattr attr;
+		struct crypto_attr_alg data;
+	} attrs[CRYPTO_MAX_ATTRS];
+
+	char template[CRYPTO_MAX_ALG_NAME];
+
+	struct crypto_larval *larval;
+
+	u32 otype;
+	u32 omask;
+};
+
+struct crypto_test_param {
+	char driver[CRYPTO_MAX_ALG_NAME];
+	char alg[CRYPTO_MAX_ALG_NAME];
+	u32 type;
+};
+
+static int cryptomgr_probe(void *data)
+{
+	struct cryptomgr_param *param = data;
+	struct crypto_template *tmpl;
+	int err = -ENOENT;
+
+	tmpl = crypto_lookup_template(param->template);
+	if (!tmpl)
+		goto out;
+
+	do {
+		err = tmpl->create(tmpl, param->tb);
+	} while (err == -EAGAIN && !signal_pending(current));
+
+	crypto_tmpl_put(tmpl);
+
+out:
+	param->larval->adult = ERR_PTR(err);
+	param->larval->alg.cra_flags |= CRYPTO_ALG_DEAD;
+	complete_all(&param->larval->completion);
+	crypto_alg_put(&param->larval->alg);
+	kfree(param);
+	module_put_and_kthread_exit(0);
+}
+
+static int cryptomgr_schedule_probe(struct crypto_larval *larval)
+{
+	struct task_struct *thread;
+	struct cryptomgr_param *param;
+	const char *name = larval->alg.cra_name;
+	const char *p;
+	unsigned int len;
+	int i;
+
+	if (!try_module_get(THIS_MODULE))
+		goto err;
+
+	param = kzalloc_obj(*param);
+	if (!param)
+		goto err_put_module;
+
+	for (p = name; isalnum(*p) || *p == '-' || *p == '_'; p++)
+		;
+
+	len = p - name;
+	if (!len || *p != '(')
+		goto err_free_param;
+
+	memcpy(param->template, name, len);
+
+	i = 0;
+	for (;;) {
+		name = ++p;
+
+		for (; isalnum(*p) || *p == '-' || *p == '_'; p++)
+			;
+
+		if (*p == '(') {
+			int recursion = 0;
+
+			for (;;) {
+				if (!*++p)
+					goto err_free_param;
+				if (*p == '(')
+					recursion++;
+				else if (*p == ')' && !recursion--)
+					break;
+			}
+
+			p++;
+		}
+
+		len = p - name;
+		if (!len)
+			goto err_free_param;
+
+		param->attrs[i].attr.rta_len = sizeof(param->attrs[i]);
+		param->attrs[i].attr.rta_type = CRYPTOA_ALG;
+		memcpy(param->attrs[i].data.name, name, len);
+
+		param->tb[i + 1] = &param->attrs[i].attr;
+		i++;
+
+		if (i >= CRYPTO_MAX_ATTRS)
+			goto err_free_param;
+
+		if (*p == ')')
+			break;
+
+		if (*p != ',')
+			goto err_free_param;
+	}
+
+	param->tb[i + 1] = NULL;
+
+	param->type.attr.rta_len = sizeof(param->type);
+	param->type.attr.rta_type = CRYPTOA_TYPE;
+	param->type.data.type = larval->alg.cra_flags & ~CRYPTO_ALG_TESTED;
+	param->type.data.mask = larval->mask & ~CRYPTO_ALG_TESTED;
+	param->tb[0] = &param->type.attr;
+
+	param->otype = larval->alg.cra_flags;
+	param->omask = larval->mask;
+
+	crypto_alg_get(&larval->alg);
+	param->larval = larval;
+
+	thread = kthread_run(cryptomgr_probe, param, "cryptomgr_probe");
+	if (IS_ERR(thread))
+		goto err_put_larval;
+
+	return NOTIFY_STOP;
+
+err_put_larval:
+	crypto_alg_put(&larval->alg);
+err_free_param:
+	kfree(param);
+err_put_module:
+	module_put(THIS_MODULE);
+err:
+	return NOTIFY_OK;
+}
+
+static int cryptomgr_test(void *data)
+{
+	struct crypto_test_param *param = data;
+	u32 type = param->type;
+	int err;
+
+	err = alg_test(param->driver, param->alg, type, CRYPTO_ALG_TESTED);
+
+	crypto_alg_tested(param->driver, err);
+
+	kfree(param);
+	module_put_and_kthread_exit(0);
+}
+
+static int cryptomgr_schedule_test(struct crypto_alg *alg)
+{
+	struct task_struct *thread;
+	struct crypto_test_param *param;
+
+	if (!IS_ENABLED(CONFIG_CRYPTO_SELFTESTS))
+		return NOTIFY_DONE;
+
+	if (!try_module_get(THIS_MODULE))
+		goto err;
+
+	param = kzalloc_obj(*param);
+	if (!param)
+		goto err_put_module;
+
+	memcpy(param->driver, alg->cra_driver_name, sizeof(param->driver));
+	memcpy(param->alg, alg->cra_name, sizeof(param->alg));
+	param->type = alg->cra_flags;
+
+	thread = kthread_run(cryptomgr_test, param, "cryptomgr_test");
+	if (IS_ERR(thread))
+		goto err_free_param;
+
+	return NOTIFY_STOP;
+
+err_free_param:
+	kfree(param);
+err_put_module:
+	module_put(THIS_MODULE);
+err:
+	return NOTIFY_OK;
+}
+
+static int cryptomgr_notify(struct notifier_block *this, unsigned long msg,
+			    void *data)
+{
+	switch (msg) {
+	case CRYPTO_MSG_ALG_REQUEST:
+		return cryptomgr_schedule_probe(data);
+	case CRYPTO_MSG_ALG_REGISTER:
+		return cryptomgr_schedule_test(data);
+	case CRYPTO_MSG_ALG_LOADED:
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block cryptomgr_notifier = {
+	.notifier_call = cryptomgr_notify,
+};
+
+static int __init cryptomgr_init(void)
+{
+	return crypto_register_notifier(&cryptomgr_notifier);
+}
+
+static void __exit cryptomgr_exit(void)
+{
+	int err = crypto_unregister_notifier(&cryptomgr_notifier);
+	BUG_ON(err);
+}
+
+module_init(cryptomgr_init);
+module_exit(cryptomgr_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Crypto Algorithm Manager");