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, 209 insertions, 0 deletions

diff --git a/security/tomoyo/group.c b/security/tomoyo/group.c
new file mode 100644
index 000000000..1cecdd797
--- /dev/null
+++ b/security/tomoyo/group.c
@@ -0,0 +1,209 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * security/tomoyo/group.c
+ *
+ * Copyright (C) 2005-2011  NTT DATA CORPORATION
+ */
+
+#include <linux/slab.h>
+#include <linux/rculist.h>
+
+#include "common.h"
+
+/**
+ * tomoyo_same_path_group - Check for duplicated "struct tomoyo_path_group" entry.
+ *
+ * @a: Pointer to "struct tomoyo_acl_head".
+ * @b: Pointer to "struct tomoyo_acl_head".
+ *
+ * Returns true if @a == @b, false otherwise.
+ */
+static bool tomoyo_same_path_group(const struct tomoyo_acl_head *a,
+				   const struct tomoyo_acl_head *b)
+{
+	return container_of(a, struct tomoyo_path_group, head)->member_name ==
+		container_of(b, struct tomoyo_path_group, head)->member_name;
+}
+
+/**
+ * tomoyo_same_number_group - Check for duplicated "struct tomoyo_number_group" entry.
+ *
+ * @a: Pointer to "struct tomoyo_acl_head".
+ * @b: Pointer to "struct tomoyo_acl_head".
+ *
+ * Returns true if @a == @b, false otherwise.
+ */
+static bool tomoyo_same_number_group(const struct tomoyo_acl_head *a,
+				     const struct tomoyo_acl_head *b)
+{
+	return !memcmp(&container_of(a, struct tomoyo_number_group, head)
+		       ->number,
+		       &container_of(b, struct tomoyo_number_group, head)
+		       ->number,
+		       sizeof(container_of(a, struct tomoyo_number_group, head)
+			      ->number));
+}
+
+/**
+ * tomoyo_same_address_group - Check for duplicated "struct tomoyo_address_group" entry.
+ *
+ * @a: Pointer to "struct tomoyo_acl_head".
+ * @b: Pointer to "struct tomoyo_acl_head".
+ *
+ * Returns true if @a == @b, false otherwise.
+ */
+static bool tomoyo_same_address_group(const struct tomoyo_acl_head *a,
+				      const struct tomoyo_acl_head *b)
+{
+	const struct tomoyo_address_group *p1 = container_of(a, typeof(*p1),
+							     head);
+	const struct tomoyo_address_group *p2 = container_of(b, typeof(*p2),
+							     head);
+
+	return tomoyo_same_ipaddr_union(&p1->address, &p2->address);
+}
+
+/**
+ * tomoyo_write_group - Write "struct tomoyo_path_group"/"struct tomoyo_number_group"/"struct tomoyo_address_group" list.
+ *
+ * @param: Pointer to "struct tomoyo_acl_param".
+ * @type:  Type of this group.
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+int tomoyo_write_group(struct tomoyo_acl_param *param, const u8 type)
+{
+	struct tomoyo_group *group = tomoyo_get_group(param, type);
+	int error = -EINVAL;
+
+	if (!group)
+		return -ENOMEM;
+	param->list = &group->member_list;
+	if (type == TOMOYO_PATH_GROUP) {
+		struct tomoyo_path_group e = { };
+
+		e.member_name = tomoyo_get_name(tomoyo_read_token(param));
+		if (!e.member_name) {
+			error = -ENOMEM;
+			goto out;
+		}
+		error = tomoyo_update_policy(&e.head, sizeof(e), param,
+					  tomoyo_same_path_group);
+		tomoyo_put_name(e.member_name);
+	} else if (type == TOMOYO_NUMBER_GROUP) {
+		struct tomoyo_number_group e = { };
+
+		if (param->data[0] == '@' ||
+		    !tomoyo_parse_number_union(param, &e.number))
+			goto out;
+		error = tomoyo_update_policy(&e.head, sizeof(e), param,
+					  tomoyo_same_number_group);
+		/*
+		 * tomoyo_put_number_union() is not needed because
+		 * param->data[0] != '@'.
+		 */
+	} else {
+		struct tomoyo_address_group e = { };
+
+		if (param->data[0] == '@' ||
+		    !tomoyo_parse_ipaddr_union(param, &e.address))
+			goto out;
+		error = tomoyo_update_policy(&e.head, sizeof(e), param,
+					     tomoyo_same_address_group);
+	}
+out:
+	tomoyo_put_group(group);
+	return error;
+}
+
+/**
+ * tomoyo_path_matches_group - Check whether the given pathname matches members of the given pathname group.
+ *
+ * @pathname: The name of pathname.
+ * @group:    Pointer to "struct tomoyo_path_group".
+ *
+ * Returns matched member's pathname if @pathname matches pathnames in @group,
+ * NULL otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
+ */
+const struct tomoyo_path_info *
+tomoyo_path_matches_group(const struct tomoyo_path_info *pathname,
+			  const struct tomoyo_group *group)
+{
+	struct tomoyo_path_group *member;
+
+	list_for_each_entry_rcu(member, &group->member_list, head.list,
+				srcu_read_lock_held(&tomoyo_ss)) {
+		if (member->head.is_deleted)
+			continue;
+		if (!tomoyo_path_matches_pattern(pathname, member->member_name))
+			continue;
+		return member->member_name;
+	}
+	return NULL;
+}
+
+/**
+ * tomoyo_number_matches_group - Check whether the given number matches members of the given number group.
+ *
+ * @min:   Min number.
+ * @max:   Max number.
+ * @group: Pointer to "struct tomoyo_number_group".
+ *
+ * Returns true if @min and @max partially overlaps @group, false otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
+ */
+bool tomoyo_number_matches_group(const unsigned long min,
+				 const unsigned long max,
+				 const struct tomoyo_group *group)
+{
+	struct tomoyo_number_group *member;
+	bool matched = false;
+
+	list_for_each_entry_rcu(member, &group->member_list, head.list,
+				srcu_read_lock_held(&tomoyo_ss)) {
+		if (member->head.is_deleted)
+			continue;
+		if (min > member->number.values[1] ||
+		    max < member->number.values[0])
+			continue;
+		matched = true;
+		break;
+	}
+	return matched;
+}
+
+/**
+ * tomoyo_address_matches_group - Check whether the given address matches members of the given address group.
+ *
+ * @is_ipv6: True if @address is an IPv6 address.
+ * @address: An IPv4 or IPv6 address.
+ * @group:   Pointer to "struct tomoyo_address_group".
+ *
+ * Returns true if @address matches addresses in @group group, false otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
+ */
+bool tomoyo_address_matches_group(const bool is_ipv6, const __be32 *address,
+				  const struct tomoyo_group *group)
+{
+	struct tomoyo_address_group *member;
+	bool matched = false;
+	const u8 size = is_ipv6 ? 16 : 4;
+
+	list_for_each_entry_rcu(member, &group->member_list, head.list,
+				srcu_read_lock_held(&tomoyo_ss)) {
+		if (member->head.is_deleted)
+			continue;
+		if (member->address.is_ipv6 != is_ipv6)
+			continue;
+		if (memcmp(&member->address.ip[0], address, size) > 0 ||
+		    memcmp(address, &member->address.ip[1], size) > 0)
+			continue;
+		matched = true;
+		break;
+	}
+	return matched;
+}