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, 228 insertions, 0 deletions

diff --git a/crypto/ecb.c b/crypto/ecb.c
new file mode 100644
index 000000000..cd1b20456
--- /dev/null
+++ b/crypto/ecb.c
@@ -0,0 +1,228 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * ECB: Electronic CodeBook mode
+ *
+ * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+
+#include <crypto/internal/cipher.h>
+#include <crypto/internal/skcipher.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+static int crypto_ecb_crypt(struct crypto_cipher *cipher, const u8 *src,
+			    u8 *dst, unsigned nbytes, bool final,
+			    void (*fn)(struct crypto_tfm *, u8 *, const u8 *))
+{
+	const unsigned int bsize = crypto_cipher_blocksize(cipher);
+
+	while (nbytes >= bsize) {
+		fn(crypto_cipher_tfm(cipher), dst, src);
+
+		src += bsize;
+		dst += bsize;
+
+		nbytes -= bsize;
+	}
+
+	return nbytes && final ? -EINVAL : nbytes;
+}
+
+static int crypto_ecb_encrypt2(struct crypto_lskcipher *tfm, const u8 *src,
+			       u8 *dst, unsigned len, u8 *iv, u32 flags)
+{
+	struct crypto_cipher **ctx = crypto_lskcipher_ctx(tfm);
+	struct crypto_cipher *cipher = *ctx;
+
+	return crypto_ecb_crypt(cipher, src, dst, len,
+				flags & CRYPTO_LSKCIPHER_FLAG_FINAL,
+				crypto_cipher_alg(cipher)->cia_encrypt);
+}
+
+static int crypto_ecb_decrypt2(struct crypto_lskcipher *tfm, const u8 *src,
+			       u8 *dst, unsigned len, u8 *iv, u32 flags)
+{
+	struct crypto_cipher **ctx = crypto_lskcipher_ctx(tfm);
+	struct crypto_cipher *cipher = *ctx;
+
+	return crypto_ecb_crypt(cipher, src, dst, len,
+				flags & CRYPTO_LSKCIPHER_FLAG_FINAL,
+				crypto_cipher_alg(cipher)->cia_decrypt);
+}
+
+static int lskcipher_setkey_simple2(struct crypto_lskcipher *tfm,
+				    const u8 *key, unsigned int keylen)
+{
+	struct crypto_cipher **ctx = crypto_lskcipher_ctx(tfm);
+	struct crypto_cipher *cipher = *ctx;
+
+	crypto_cipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK);
+	crypto_cipher_set_flags(cipher, crypto_lskcipher_get_flags(tfm) &
+				CRYPTO_TFM_REQ_MASK);
+	return crypto_cipher_setkey(cipher, key, keylen);
+}
+
+static int lskcipher_init_tfm_simple2(struct crypto_lskcipher *tfm)
+{
+	struct lskcipher_instance *inst = lskcipher_alg_instance(tfm);
+	struct crypto_cipher **ctx = crypto_lskcipher_ctx(tfm);
+	struct crypto_cipher_spawn *spawn;
+	struct crypto_cipher *cipher;
+
+	spawn = lskcipher_instance_ctx(inst);
+	cipher = crypto_spawn_cipher(spawn);
+	if (IS_ERR(cipher))
+		return PTR_ERR(cipher);
+
+	*ctx = cipher;
+	return 0;
+}
+
+static void lskcipher_exit_tfm_simple2(struct crypto_lskcipher *tfm)
+{
+	struct crypto_cipher **ctx = crypto_lskcipher_ctx(tfm);
+
+	crypto_free_cipher(*ctx);
+}
+
+static void lskcipher_free_instance_simple2(struct lskcipher_instance *inst)
+{
+	crypto_drop_cipher(lskcipher_instance_ctx(inst));
+	kfree(inst);
+}
+
+static struct lskcipher_instance *lskcipher_alloc_instance_simple2(
+	struct crypto_template *tmpl, struct rtattr **tb)
+{
+	struct crypto_cipher_spawn *spawn;
+	struct lskcipher_instance *inst;
+	struct crypto_alg *cipher_alg;
+	u32 mask;
+	int err;
+
+	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_LSKCIPHER, &mask);
+	if (err)
+		return ERR_PTR(err);
+
+	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
+	if (!inst)
+		return ERR_PTR(-ENOMEM);
+	spawn = lskcipher_instance_ctx(inst);
+
+	err = crypto_grab_cipher(spawn, lskcipher_crypto_instance(inst),
+				 crypto_attr_alg_name(tb[1]), 0, mask);
+	if (err)
+		goto err_free_inst;
+	cipher_alg = crypto_spawn_cipher_alg(spawn);
+
+	err = crypto_inst_setname(lskcipher_crypto_instance(inst), tmpl->name,
+				  cipher_alg);
+	if (err)
+		goto err_free_inst;
+
+	inst->free = lskcipher_free_instance_simple2;
+
+	/* Default algorithm properties, can be overridden */
+	inst->alg.co.base.cra_blocksize = cipher_alg->cra_blocksize;
+	inst->alg.co.base.cra_alignmask = cipher_alg->cra_alignmask;
+	inst->alg.co.base.cra_priority = cipher_alg->cra_priority;
+	inst->alg.co.min_keysize = cipher_alg->cra_cipher.cia_min_keysize;
+	inst->alg.co.max_keysize = cipher_alg->cra_cipher.cia_max_keysize;
+	inst->alg.co.ivsize = cipher_alg->cra_blocksize;
+
+	/* Use struct crypto_cipher * by default, can be overridden */
+	inst->alg.co.base.cra_ctxsize = sizeof(struct crypto_cipher *);
+	inst->alg.setkey = lskcipher_setkey_simple2;
+	inst->alg.init = lskcipher_init_tfm_simple2;
+	inst->alg.exit = lskcipher_exit_tfm_simple2;
+
+	return inst;
+
+err_free_inst:
+	lskcipher_free_instance_simple2(inst);
+	return ERR_PTR(err);
+}
+
+static int crypto_ecb_create2(struct crypto_template *tmpl, struct rtattr **tb)
+{
+	struct lskcipher_instance *inst;
+	int err;
+
+	inst = lskcipher_alloc_instance_simple2(tmpl, tb);
+	if (IS_ERR(inst))
+		return PTR_ERR(inst);
+
+	/* ECB mode doesn't take an IV */
+	inst->alg.co.ivsize = 0;
+
+	inst->alg.encrypt = crypto_ecb_encrypt2;
+	inst->alg.decrypt = crypto_ecb_decrypt2;
+
+	err = lskcipher_register_instance(tmpl, inst);
+	if (err)
+		inst->free(inst);
+
+	return err;
+}
+
+static int crypto_ecb_create(struct crypto_template *tmpl, struct rtattr **tb)
+{
+	struct crypto_lskcipher_spawn *spawn;
+	struct lskcipher_alg *cipher_alg;
+	struct lskcipher_instance *inst;
+	int err;
+
+	inst = lskcipher_alloc_instance_simple(tmpl, tb);
+	if (IS_ERR(inst)) {
+		err = crypto_ecb_create2(tmpl, tb);
+		return err;
+	}
+
+	spawn = lskcipher_instance_ctx(inst);
+	cipher_alg = crypto_lskcipher_spawn_alg(spawn);
+
+	/* ECB mode doesn't take an IV */
+	inst->alg.co.ivsize = 0;
+	if (cipher_alg->co.ivsize)
+		return -EINVAL;
+
+	inst->alg.co.base.cra_ctxsize = cipher_alg->co.base.cra_ctxsize;
+	inst->alg.setkey = cipher_alg->setkey;
+	inst->alg.encrypt = cipher_alg->encrypt;
+	inst->alg.decrypt = cipher_alg->decrypt;
+	inst->alg.init = cipher_alg->init;
+	inst->alg.exit = cipher_alg->exit;
+
+	err = lskcipher_register_instance(tmpl, inst);
+	if (err)
+		inst->free(inst);
+
+	return err;
+}
+
+static struct crypto_template crypto_ecb_tmpl = {
+	.name = "ecb",
+	.create = crypto_ecb_create,
+	.module = THIS_MODULE,
+};
+
+static int __init crypto_ecb_module_init(void)
+{
+	return crypto_register_template(&crypto_ecb_tmpl);
+}
+
+static void __exit crypto_ecb_module_exit(void)
+{
+	crypto_unregister_template(&crypto_ecb_tmpl);
+}
+
+module_init(crypto_ecb_module_init);
+module_exit(crypto_ecb_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("ECB block cipher mode of operation");
+MODULE_ALIAS_CRYPTO("ecb");
+MODULE_IMPORT_NS("CRYPTO_INTERNAL");