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, 262 insertions, 0 deletions

diff --git a/crypto/tea.c b/crypto/tea.c
new file mode 100644
index 000000000..7c66efcb5
--- /dev/null
+++ b/crypto/tea.c
@@ -0,0 +1,262 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* 
+ * Cryptographic API.
+ *
+ * TEA, XTEA, and XETA crypto algorithms
+ *
+ * The TEA and Xtended TEA algorithms were developed by David Wheeler 
+ * and Roger Needham at the Computer Laboratory of Cambridge University.
+ *
+ * Due to the order of evaluation in XTEA many people have incorrectly
+ * implemented it.  XETA (XTEA in the wrong order), exists for
+ * compatibility with these implementations.
+ *
+ * Copyright (c) 2004 Aaron Grothe ajgrothe@yahoo.com
+ */
+
+#include <crypto/algapi.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/unaligned.h>
+#include <linux/types.h>
+
+#define TEA_KEY_SIZE		16
+#define TEA_BLOCK_SIZE		8
+#define TEA_ROUNDS		32
+#define TEA_DELTA		0x9e3779b9
+
+#define XTEA_KEY_SIZE		16
+#define XTEA_BLOCK_SIZE		8
+#define XTEA_ROUNDS		32
+#define XTEA_DELTA		0x9e3779b9
+
+struct tea_ctx {
+	u32 KEY[4];
+};
+
+struct xtea_ctx {
+	u32 KEY[4];
+};
+
+static int tea_setkey(struct crypto_tfm *tfm, const u8 *in_key,
+		      unsigned int key_len)
+{
+	struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	ctx->KEY[0] = get_unaligned_le32(&in_key[0]);
+	ctx->KEY[1] = get_unaligned_le32(&in_key[4]);
+	ctx->KEY[2] = get_unaligned_le32(&in_key[8]);
+	ctx->KEY[3] = get_unaligned_le32(&in_key[12]);
+
+	return 0; 
+
+}
+
+static void tea_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
+{
+	u32 y, z, n, sum = 0;
+	u32 k0, k1, k2, k3;
+	struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	y = get_unaligned_le32(&src[0]);
+	z = get_unaligned_le32(&src[4]);
+
+	k0 = ctx->KEY[0];
+	k1 = ctx->KEY[1];
+	k2 = ctx->KEY[2];
+	k3 = ctx->KEY[3];
+
+	n = TEA_ROUNDS;
+
+	while (n-- > 0) {
+		sum += TEA_DELTA;
+		y += ((z << 4) + k0) ^ (z + sum) ^ ((z >> 5) + k1);
+		z += ((y << 4) + k2) ^ (y + sum) ^ ((y >> 5) + k3);
+	}
+	
+	put_unaligned_le32(y, &dst[0]);
+	put_unaligned_le32(z, &dst[4]);
+}
+
+static void tea_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
+{
+	u32 y, z, n, sum;
+	u32 k0, k1, k2, k3;
+	struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	y = get_unaligned_le32(&src[0]);
+	z = get_unaligned_le32(&src[4]);
+
+	k0 = ctx->KEY[0];
+	k1 = ctx->KEY[1];
+	k2 = ctx->KEY[2];
+	k3 = ctx->KEY[3];
+
+	sum = TEA_DELTA << 5;
+
+	n = TEA_ROUNDS;
+
+	while (n-- > 0) {
+		z -= ((y << 4) + k2) ^ (y + sum) ^ ((y >> 5) + k3);
+		y -= ((z << 4) + k0) ^ (z + sum) ^ ((z >> 5) + k1);
+		sum -= TEA_DELTA;
+	}
+	
+	put_unaligned_le32(y, &dst[0]);
+	put_unaligned_le32(z, &dst[4]);
+}
+
+static int xtea_setkey(struct crypto_tfm *tfm, const u8 *in_key,
+		       unsigned int key_len)
+{
+	struct xtea_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	ctx->KEY[0] = get_unaligned_le32(&in_key[0]);
+	ctx->KEY[1] = get_unaligned_le32(&in_key[4]);
+	ctx->KEY[2] = get_unaligned_le32(&in_key[8]);
+	ctx->KEY[3] = get_unaligned_le32(&in_key[12]);
+
+	return 0; 
+
+}
+
+static void xtea_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
+{
+	u32 y, z, sum = 0;
+	u32 limit = XTEA_DELTA * XTEA_ROUNDS;
+	struct xtea_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	y = get_unaligned_le32(&src[0]);
+	z = get_unaligned_le32(&src[4]);
+
+	while (sum != limit) {
+		y += ((z << 4 ^ z >> 5) + z) ^ (sum + ctx->KEY[sum&3]); 
+		sum += XTEA_DELTA;
+		z += ((y << 4 ^ y >> 5) + y) ^ (sum + ctx->KEY[sum>>11 &3]); 
+	}
+	
+	put_unaligned_le32(y, &dst[0]);
+	put_unaligned_le32(z, &dst[4]);
+}
+
+static void xtea_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
+{
+	u32 y, z, sum;
+	struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	y = get_unaligned_le32(&src[0]);
+	z = get_unaligned_le32(&src[4]);
+
+	sum = XTEA_DELTA * XTEA_ROUNDS;
+
+	while (sum) {
+		z -= ((y << 4 ^ y >> 5) + y) ^ (sum + ctx->KEY[sum>>11 & 3]);
+		sum -= XTEA_DELTA;
+		y -= ((z << 4 ^ z >> 5) + z) ^ (sum + ctx->KEY[sum & 3]);
+	}
+	
+	put_unaligned_le32(y, &dst[0]);
+	put_unaligned_le32(z, &dst[4]);
+}
+
+
+static void xeta_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
+{
+	u32 y, z, sum = 0;
+	u32 limit = XTEA_DELTA * XTEA_ROUNDS;
+	struct xtea_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	y = get_unaligned_le32(&src[0]);
+	z = get_unaligned_le32(&src[4]);
+
+	while (sum != limit) {
+		y += (z << 4 ^ z >> 5) + (z ^ sum) + ctx->KEY[sum&3];
+		sum += XTEA_DELTA;
+		z += (y << 4 ^ y >> 5) + (y ^ sum) + ctx->KEY[sum>>11 &3];
+	}
+	
+	put_unaligned_le32(y, &dst[0]);
+	put_unaligned_le32(z, &dst[4]);
+}
+
+static void xeta_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
+{
+	u32 y, z, sum;
+	struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	y = get_unaligned_le32(&src[0]);
+	z = get_unaligned_le32(&src[4]);
+
+	sum = XTEA_DELTA * XTEA_ROUNDS;
+
+	while (sum) {
+		z -= (y << 4 ^ y >> 5) + (y ^ sum) + ctx->KEY[sum>>11 & 3];
+		sum -= XTEA_DELTA;
+		y -= (z << 4 ^ z >> 5) + (z ^ sum) + ctx->KEY[sum & 3];
+	}
+	
+	put_unaligned_le32(y, &dst[0]);
+	put_unaligned_le32(z, &dst[4]);
+}
+
+static struct crypto_alg tea_algs[3] = { {
+	.cra_name		=	"tea",
+	.cra_driver_name	=	"tea-generic",
+	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
+	.cra_blocksize		=	TEA_BLOCK_SIZE,
+	.cra_ctxsize		=	sizeof (struct tea_ctx),
+	.cra_module		=	THIS_MODULE,
+	.cra_u			=	{ .cipher = {
+	.cia_min_keysize	=	TEA_KEY_SIZE,
+	.cia_max_keysize	=	TEA_KEY_SIZE,
+	.cia_setkey		= 	tea_setkey,
+	.cia_encrypt		=	tea_encrypt,
+	.cia_decrypt		=	tea_decrypt } }
+}, {
+	.cra_name		=	"xtea",
+	.cra_driver_name	=	"xtea-generic",
+	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
+	.cra_blocksize		=	XTEA_BLOCK_SIZE,
+	.cra_ctxsize		=	sizeof (struct xtea_ctx),
+	.cra_module		=	THIS_MODULE,
+	.cra_u			=	{ .cipher = {
+	.cia_min_keysize	=	XTEA_KEY_SIZE,
+	.cia_max_keysize	=	XTEA_KEY_SIZE,
+	.cia_setkey		= 	xtea_setkey,
+	.cia_encrypt		=	xtea_encrypt,
+	.cia_decrypt		=	xtea_decrypt } }
+}, {
+	.cra_name		=	"xeta",
+	.cra_driver_name	=	"xeta-generic",
+	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
+	.cra_blocksize		=	XTEA_BLOCK_SIZE,
+	.cra_ctxsize		=	sizeof (struct xtea_ctx),
+	.cra_module		=	THIS_MODULE,
+	.cra_u			=	{ .cipher = {
+	.cia_min_keysize	=	XTEA_KEY_SIZE,
+	.cia_max_keysize	=	XTEA_KEY_SIZE,
+	.cia_setkey		= 	xtea_setkey,
+	.cia_encrypt		=	xeta_encrypt,
+	.cia_decrypt		=	xeta_decrypt } }
+} };
+
+static int __init tea_mod_init(void)
+{
+	return crypto_register_algs(tea_algs, ARRAY_SIZE(tea_algs));
+}
+
+static void __exit tea_mod_fini(void)
+{
+	crypto_unregister_algs(tea_algs, ARRAY_SIZE(tea_algs));
+}
+
+MODULE_ALIAS_CRYPTO("tea");
+MODULE_ALIAS_CRYPTO("xtea");
+MODULE_ALIAS_CRYPTO("xeta");
+
+module_init(tea_mod_init);
+module_exit(tea_mod_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("TEA, XTEA & XETA Cryptographic Algorithms");