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, 70 insertions, 0 deletions

diff --git a/security/ipe/eval.h b/security/ipe/eval.h
new file mode 100644
index 000000000..fef65a364
--- /dev/null
+++ b/security/ipe/eval.h
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+
+#ifndef _IPE_EVAL_H
+#define _IPE_EVAL_H
+
+#include <linux/file.h>
+#include <linux/types.h>
+
+#include "policy.h"
+#include "hooks.h"
+
+#define IPE_EVAL_CTX_INIT ((struct ipe_eval_ctx){ 0 })
+
+extern struct ipe_policy __rcu *ipe_active_policy;
+extern bool success_audit;
+extern bool enforce;
+
+struct ipe_superblock {
+	bool initramfs;
+};
+
+#ifdef CONFIG_IPE_PROP_DM_VERITY
+struct ipe_bdev {
+#ifdef CONFIG_IPE_PROP_DM_VERITY_SIGNATURE
+	bool dm_verity_signed;
+#endif /* CONFIG_IPE_PROP_DM_VERITY_SIGNATURE */
+	struct digest_info *root_hash;
+};
+#endif /* CONFIG_IPE_PROP_DM_VERITY */
+
+#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG
+struct ipe_inode {
+	bool fs_verity_signed;
+};
+#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
+
+struct ipe_eval_ctx {
+	enum ipe_op_type op;
+	enum ipe_hook_type hook;
+
+	const struct file *file;
+	bool initramfs;
+#ifdef CONFIG_IPE_PROP_DM_VERITY
+	const struct ipe_bdev *ipe_bdev;
+#endif /* CONFIG_IPE_PROP_DM_VERITY */
+#ifdef CONFIG_IPE_PROP_FS_VERITY
+	const struct inode *ino;
+#endif /* CONFIG_IPE_PROP_FS_VERITY */
+#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG
+	const struct ipe_inode *ipe_inode;
+#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
+};
+
+enum ipe_match {
+	IPE_MATCH_RULE = 0,
+	IPE_MATCH_TABLE,
+	IPE_MATCH_GLOBAL,
+	__IPE_MATCH_MAX
+};
+
+void ipe_build_eval_ctx(struct ipe_eval_ctx *ctx,
+			const struct file *file,
+			enum ipe_op_type op,
+			enum ipe_hook_type hook);
+int ipe_evaluate_event(const struct ipe_eval_ctx *const ctx);
+
+#endif /* _IPE_EVAL_H */