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, 43 insertions, 0 deletions

diff --git a/net/mac80211/aes_cmac.c b/net/mac80211/aes_cmac.c
new file mode 100644
index 000000000..55b674ad7
--- /dev/null
+++ b/net/mac80211/aes_cmac.c
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AES-128-CMAC with TLen 16 for IEEE 802.11w BIP
+ * Copyright 2008, Jouni Malinen <j@w1.fi>
+ * Copyright (C) 2020 Intel Corporation
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/export.h>
+#include <linux/err.h>
+#include <crypto/aes-cbc-macs.h>
+
+#include <net/mac80211.h>
+#include "key.h"
+#include "aes_cmac.h"
+
+#define AAD_LEN 20
+
+static const u8 zero[IEEE80211_CMAC_256_MIC_LEN];
+
+void ieee80211_aes_cmac(const struct aes_cmac_key *key, const u8 *aad,
+			const u8 *data, size_t data_len, u8 *mic,
+			unsigned int mic_len)
+{
+	struct aes_cmac_ctx ctx;
+	u8 out[AES_BLOCK_SIZE];
+	const __le16 *fc;
+
+	aes_cmac_init(&ctx, key);
+	aes_cmac_update(&ctx, aad, AAD_LEN);
+	fc = (const __le16 *)aad;
+	if (ieee80211_is_beacon(*fc)) {
+		/* mask Timestamp field to zero */
+		aes_cmac_update(&ctx, zero, 8);
+		aes_cmac_update(&ctx, data + 8, data_len - 8 - mic_len);
+	} else {
+		aes_cmac_update(&ctx, data, data_len - mic_len);
+	}
+	aes_cmac_update(&ctx, zero, mic_len);
+	aes_cmac_final(&ctx, out);
+	memcpy(mic, out, mic_len);
+}