From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops 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 --- crypto/crypto_null.c | 124 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 124 insertions(+) create mode 100644 crypto/crypto_null.c (limited to 'crypto/crypto_null.c') diff --git a/crypto/crypto_null.c b/crypto/crypto_null.c new file mode 100644 index 000000000..fea151df1 --- /dev/null +++ b/crypto/crypto_null.c @@ -0,0 +1,124 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Cryptographic API. + * + * Null algorithms, aka Much Ado About Nothing. + * + * These are needed for IPsec, and may be useful in general for + * testing & debugging. + * + * The null cipher is compliant with RFC2410. + * + * Copyright (c) 2002 James Morris + */ + +#include +#include +#include +#include +#include +#include +#include + +static int null_init(struct shash_desc *desc) +{ + return 0; +} + +static int null_update(struct shash_desc *desc, const u8 *data, + unsigned int len) +{ + return 0; +} + +static int null_final(struct shash_desc *desc, u8 *out) +{ + return 0; +} + +static int null_digest(struct shash_desc *desc, const u8 *data, + unsigned int len, u8 *out) +{ + return 0; +} + +static int null_hash_setkey(struct crypto_shash *tfm, const u8 *key, + unsigned int keylen) +{ return 0; } + +static int null_skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key, + unsigned int keylen) +{ return 0; } + +static int null_skcipher_crypt(struct skcipher_request *req) +{ + if (req->src != req->dst) + memcpy_sglist(req->dst, req->src, req->cryptlen); + return 0; +} + +static struct shash_alg digest_null = { + .digestsize = NULL_DIGEST_SIZE, + .setkey = null_hash_setkey, + .init = null_init, + .update = null_update, + .finup = null_digest, + .digest = null_digest, + .final = null_final, + .base = { + .cra_name = "digest_null", + .cra_driver_name = "digest_null-generic", + .cra_blocksize = NULL_BLOCK_SIZE, + .cra_module = THIS_MODULE, + } +}; + +static struct skcipher_alg skcipher_null = { + .base.cra_name = "ecb(cipher_null)", + .base.cra_driver_name = "ecb-cipher_null", + .base.cra_priority = 100, + .base.cra_blocksize = NULL_BLOCK_SIZE, + .base.cra_ctxsize = 0, + .base.cra_module = THIS_MODULE, + .min_keysize = NULL_KEY_SIZE, + .max_keysize = NULL_KEY_SIZE, + .ivsize = NULL_IV_SIZE, + .setkey = null_skcipher_setkey, + .encrypt = null_skcipher_crypt, + .decrypt = null_skcipher_crypt, +}; + +MODULE_ALIAS_CRYPTO("digest_null"); +MODULE_ALIAS_CRYPTO("ecb(cipher_null)"); + +static int __init crypto_null_mod_init(void) +{ + int ret = 0; + + ret = crypto_register_shash(&digest_null); + if (ret < 0) + goto out; + + ret = crypto_register_skcipher(&skcipher_null); + if (ret < 0) + goto out_unregister_shash; + + return 0; + +out_unregister_shash: + crypto_unregister_shash(&digest_null); +out: + return ret; +} + +static void __exit crypto_null_mod_fini(void) +{ + crypto_unregister_shash(&digest_null); + crypto_unregister_skcipher(&skcipher_null); +} + +module_init(crypto_null_mod_init); +module_exit(crypto_null_mod_fini); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Null Cryptographic Algorithms"); -- cgit v1.3.1