Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 559 insertions, 0 deletions

diff --git a/security/ipe/policy_parser.c b/security/ipe/policy_parser.c
new file mode 100644
index 000000000..6fa5bebf8
--- /dev/null
+++ b/security/ipe/policy_parser.c
@@ -0,0 +1,559 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/parser.h>
+#include <linux/types.h>
+#include <linux/ctype.h>
+
+#include "policy.h"
+#include "policy_parser.h"
+#include "digest.h"
+
+#define START_COMMENT	'#'
+#define IPE_POLICY_DELIM " \t"
+#define IPE_LINE_DELIM "\n\r"
+
+/**
+ * new_parsed_policy() - Allocate and initialize a parsed policy.
+ *
+ * Return:
+ * * a pointer to the ipe_parsed_policy structure	- Success
+ * * %-ENOMEM						- Out of memory (OOM)
+ */
+static struct ipe_parsed_policy *new_parsed_policy(void)
+{
+	struct ipe_parsed_policy *p = NULL;
+	struct ipe_op_table *t = NULL;
+	size_t i = 0;
+
+	p = kzalloc_obj(*p);
+	if (!p)
+		return ERR_PTR(-ENOMEM);
+
+	p->global_default_action = IPE_ACTION_INVALID;
+
+	for (i = 0; i < ARRAY_SIZE(p->rules); ++i) {
+		t = &p->rules[i];
+
+		t->default_action = IPE_ACTION_INVALID;
+		INIT_LIST_HEAD(&t->rules);
+	}
+
+	return p;
+}
+
+/**
+ * remove_comment() - Truncate all chars following START_COMMENT in a string.
+ *
+ * @line: Supplies a policy line string for preprocessing.
+ */
+static void remove_comment(char *line)
+{
+	line = strchr(line, START_COMMENT);
+
+	if (line)
+		*line = '\0';
+}
+
+/**
+ * remove_trailing_spaces() - Truncate all trailing spaces in a string.
+ *
+ * @line: Supplies a policy line string for preprocessing.
+ *
+ * Return: The length of truncated string.
+ */
+static size_t remove_trailing_spaces(char *line)
+{
+	size_t i = 0;
+
+	i = strlen(line);
+	while (i > 0 && isspace(line[i - 1]))
+		i--;
+
+	line[i] = '\0';
+
+	return i;
+}
+
+/**
+ * parse_version() - Parse policy version.
+ * @ver: Supplies a version string to be parsed.
+ * @p: Supplies the partial parsed policy.
+ *
+ * Return:
+ * * %0		- Success
+ * * %-EBADMSG	- Version string is invalid
+ * * %-ERANGE	- Version number overflow
+ * * %-EINVAL	- Parsing error
+ */
+static int parse_version(char *ver, struct ipe_parsed_policy *p)
+{
+	u16 *const cv[] = { &p->version.major, &p->version.minor, &p->version.rev };
+	size_t sep_count = 0;
+	char *token;
+	int rc = 0;
+
+	while ((token = strsep(&ver, ".")) != NULL) {
+		/* prevent overflow */
+		if (sep_count >= ARRAY_SIZE(cv))
+			return -EBADMSG;
+
+		rc = kstrtou16(token, 10, cv[sep_count]);
+		if (rc)
+			return rc;
+
+		++sep_count;
+	}
+
+	/* prevent underflow */
+	if (sep_count != ARRAY_SIZE(cv))
+		return -EBADMSG;
+
+	return 0;
+}
+
+enum header_opt {
+	IPE_HEADER_POLICY_NAME = 0,
+	IPE_HEADER_POLICY_VERSION,
+	__IPE_HEADER_MAX
+};
+
+static const match_table_t header_tokens = {
+	{IPE_HEADER_POLICY_NAME,	"policy_name=%s"},
+	{IPE_HEADER_POLICY_VERSION,	"policy_version=%s"},
+	{__IPE_HEADER_MAX,		NULL}
+};
+
+/**
+ * parse_header() - Parse policy header information.
+ * @line: Supplies header line to be parsed.
+ * @p: Supplies the partial parsed policy.
+ *
+ * Return:
+ * * %0		- Success
+ * * %-EBADMSG	- Header string is invalid
+ * * %-ENOMEM	- Out of memory (OOM)
+ * * %-ERANGE	- Version number overflow
+ * * %-EINVAL	- Version parsing error
+ */
+static int parse_header(char *line, struct ipe_parsed_policy *p)
+{
+	substring_t args[MAX_OPT_ARGS];
+	char *t, *ver = NULL;
+	size_t idx = 0;
+	int rc = 0;
+
+	while ((t = strsep(&line, IPE_POLICY_DELIM)) != NULL) {
+		int token;
+
+		if (*t == '\0')
+			continue;
+		if (idx >= __IPE_HEADER_MAX) {
+			rc = -EBADMSG;
+			goto out;
+		}
+
+		token = match_token(t, header_tokens, args);
+		if (token != idx) {
+			rc = -EBADMSG;
+			goto out;
+		}
+
+		switch (token) {
+		case IPE_HEADER_POLICY_NAME:
+			p->name = match_strdup(&args[0]);
+			if (!p->name)
+				rc = -ENOMEM;
+			break;
+		case IPE_HEADER_POLICY_VERSION:
+			ver = match_strdup(&args[0]);
+			if (!ver) {
+				rc = -ENOMEM;
+				break;
+			}
+			rc = parse_version(ver, p);
+			break;
+		default:
+			rc = -EBADMSG;
+		}
+		if (rc)
+			goto out;
+		++idx;
+	}
+
+	if (idx != __IPE_HEADER_MAX)
+		rc = -EBADMSG;
+
+out:
+	kfree(ver);
+	return rc;
+}
+
+/**
+ * token_default() - Determine if the given token is "DEFAULT".
+ * @token: Supplies the token string to be compared.
+ *
+ * Return:
+ * * %false	- The token is not "DEFAULT"
+ * * %true	- The token is "DEFAULT"
+ */
+static bool token_default(char *token)
+{
+	return !strcmp(token, "DEFAULT");
+}
+
+/**
+ * free_rule() - Free the supplied ipe_rule struct.
+ * @r: Supplies the ipe_rule struct to be freed.
+ *
+ * Free a ipe_rule struct @r. Note @r must be removed from any lists before
+ * calling this function.
+ */
+static void free_rule(struct ipe_rule *r)
+{
+	struct ipe_prop *p, *t;
+
+	if (IS_ERR_OR_NULL(r))
+		return;
+
+	list_for_each_entry_safe(p, t, &r->props, next) {
+		list_del(&p->next);
+		ipe_digest_free(p->value);
+		kfree(p);
+	}
+
+	kfree(r);
+}
+
+static const match_table_t operation_tokens = {
+	{IPE_OP_EXEC,			"op=EXECUTE"},
+	{IPE_OP_FIRMWARE,		"op=FIRMWARE"},
+	{IPE_OP_KERNEL_MODULE,		"op=KMODULE"},
+	{IPE_OP_KEXEC_IMAGE,		"op=KEXEC_IMAGE"},
+	{IPE_OP_KEXEC_INITRAMFS,	"op=KEXEC_INITRAMFS"},
+	{IPE_OP_POLICY,			"op=POLICY"},
+	{IPE_OP_X509,			"op=X509_CERT"},
+	{IPE_OP_INVALID,		NULL}
+};
+
+/**
+ * parse_operation() - Parse the operation type given a token string.
+ * @t: Supplies the token string to be parsed.
+ *
+ * Return: The parsed operation type.
+ */
+static enum ipe_op_type parse_operation(char *t)
+{
+	substring_t args[MAX_OPT_ARGS];
+
+	return match_token(t, operation_tokens, args);
+}
+
+static const match_table_t action_tokens = {
+	{IPE_ACTION_ALLOW,	"action=ALLOW"},
+	{IPE_ACTION_DENY,	"action=DENY"},
+	{IPE_ACTION_INVALID,	NULL}
+};
+
+/**
+ * parse_action() - Parse the action type given a token string.
+ * @t: Supplies the token string to be parsed.
+ *
+ * Return: The parsed action type.
+ */
+static enum ipe_action_type parse_action(char *t)
+{
+	substring_t args[MAX_OPT_ARGS];
+
+	return match_token(t, action_tokens, args);
+}
+
+static const match_table_t property_tokens = {
+	{IPE_PROP_BOOT_VERIFIED_FALSE,	"boot_verified=FALSE"},
+	{IPE_PROP_BOOT_VERIFIED_TRUE,	"boot_verified=TRUE"},
+	{IPE_PROP_DMV_ROOTHASH,		"dmverity_roothash=%s"},
+	{IPE_PROP_DMV_SIG_FALSE,	"dmverity_signature=FALSE"},
+	{IPE_PROP_DMV_SIG_TRUE,		"dmverity_signature=TRUE"},
+	{IPE_PROP_FSV_DIGEST,		"fsverity_digest=%s"},
+	{IPE_PROP_FSV_SIG_FALSE,	"fsverity_signature=FALSE"},
+	{IPE_PROP_FSV_SIG_TRUE,		"fsverity_signature=TRUE"},
+	{IPE_PROP_INVALID,		NULL}
+};
+
+/**
+ * parse_property() - Parse a rule property given a token string.
+ * @t: Supplies the token string to be parsed.
+ * @r: Supplies the ipe_rule the parsed property will be associated with.
+ *
+ * This function parses and associates a property with an IPE rule based
+ * on a token string.
+ *
+ * Return:
+ * * %0		- Success
+ * * %-ENOMEM	- Out of memory (OOM)
+ * * %-EBADMSG	- The supplied token cannot be parsed
+ */
+static int parse_property(char *t, struct ipe_rule *r)
+{
+	substring_t args[MAX_OPT_ARGS];
+	struct ipe_prop *p = NULL;
+	int rc = 0;
+	int token;
+	char *dup = NULL;
+
+	p = kzalloc_obj(*p);
+	if (!p)
+		return -ENOMEM;
+
+	token = match_token(t, property_tokens, args);
+
+	switch (token) {
+	case IPE_PROP_DMV_ROOTHASH:
+	case IPE_PROP_FSV_DIGEST:
+		dup = match_strdup(&args[0]);
+		if (!dup) {
+			rc = -ENOMEM;
+			goto err;
+		}
+		p->value = ipe_digest_parse(dup);
+		if (IS_ERR(p->value)) {
+			rc = PTR_ERR(p->value);
+			goto err;
+		}
+		fallthrough;
+	case IPE_PROP_BOOT_VERIFIED_FALSE:
+	case IPE_PROP_BOOT_VERIFIED_TRUE:
+	case IPE_PROP_DMV_SIG_FALSE:
+	case IPE_PROP_DMV_SIG_TRUE:
+	case IPE_PROP_FSV_SIG_FALSE:
+	case IPE_PROP_FSV_SIG_TRUE:
+		p->type = token;
+		break;
+	default:
+		rc = -EBADMSG;
+		break;
+	}
+	if (rc)
+		goto err;
+	list_add_tail(&p->next, &r->props);
+
+out:
+	kfree(dup);
+	return rc;
+err:
+	kfree(p);
+	goto out;
+}
+
+/**
+ * parse_rule() - parse a policy rule line.
+ * @line: Supplies rule line to be parsed.
+ * @p: Supplies the partial parsed policy.
+ *
+ * Return:
+ * * 0		- Success
+ * * %-ENOMEM	- Out of memory (OOM)
+ * * %-EBADMSG	- Policy syntax error
+ */
+static int parse_rule(char *line, struct ipe_parsed_policy *p)
+{
+	enum ipe_action_type action = IPE_ACTION_INVALID;
+	enum ipe_op_type op = IPE_OP_INVALID;
+	bool is_default_rule = false;
+	struct ipe_rule *r = NULL;
+	bool first_token = true;
+	bool op_parsed = false;
+	int rc = 0;
+	char *t;
+
+	if (IS_ERR_OR_NULL(line))
+		return -EBADMSG;
+
+	r = kzalloc_obj(*r);
+	if (!r)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&r->next);
+	INIT_LIST_HEAD(&r->props);
+
+	while (t = strsep(&line, IPE_POLICY_DELIM), line) {
+		if (*t == '\0')
+			continue;
+		if (first_token && token_default(t)) {
+			is_default_rule = true;
+		} else {
+			if (!op_parsed) {
+				op = parse_operation(t);
+				if (op == IPE_OP_INVALID)
+					rc = -EBADMSG;
+				else
+					op_parsed = true;
+			} else {
+				rc = parse_property(t, r);
+			}
+		}
+
+		if (rc)
+			goto err;
+		first_token = false;
+	}
+
+	action = parse_action(t);
+	if (action == IPE_ACTION_INVALID) {
+		rc = -EBADMSG;
+		goto err;
+	}
+
+	if (is_default_rule) {
+		if (!list_empty(&r->props)) {
+			rc = -EBADMSG;
+		} else if (op == IPE_OP_INVALID) {
+			if (p->global_default_action != IPE_ACTION_INVALID)
+				rc = -EBADMSG;
+			else
+				p->global_default_action = action;
+		} else {
+			if (p->rules[op].default_action != IPE_ACTION_INVALID)
+				rc = -EBADMSG;
+			else
+				p->rules[op].default_action = action;
+		}
+	} else if (op != IPE_OP_INVALID && action != IPE_ACTION_INVALID) {
+		r->op = op;
+		r->action = action;
+	} else {
+		rc = -EBADMSG;
+	}
+
+	if (rc)
+		goto err;
+	if (!is_default_rule)
+		list_add_tail(&r->next, &p->rules[op].rules);
+	else
+		free_rule(r);
+
+	return rc;
+err:
+	free_rule(r);
+	return rc;
+}
+
+/**
+ * ipe_free_parsed_policy() - free a parsed policy structure.
+ * @p: Supplies the parsed policy.
+ */
+void ipe_free_parsed_policy(struct ipe_parsed_policy *p)
+{
+	struct ipe_rule *pp, *t;
+	size_t i = 0;
+
+	if (IS_ERR_OR_NULL(p))
+		return;
+
+	for (i = 0; i < ARRAY_SIZE(p->rules); ++i)
+		list_for_each_entry_safe(pp, t, &p->rules[i].rules, next) {
+			list_del(&pp->next);
+			free_rule(pp);
+		}
+
+	kfree(p->name);
+	kfree(p);
+}
+
+/**
+ * validate_policy() - validate a parsed policy.
+ * @p: Supplies the fully parsed policy.
+ *
+ * Given a policy structure that was just parsed, validate that all
+ * operations have their default rules or a global default rule is set.
+ *
+ * Return:
+ * * %0		- Success
+ * * %-EBADMSG	- Policy is invalid
+ */
+static int validate_policy(const struct ipe_parsed_policy *p)
+{
+	size_t i = 0;
+
+	if (p->global_default_action != IPE_ACTION_INVALID)
+		return 0;
+
+	for (i = 0; i < ARRAY_SIZE(p->rules); ++i) {
+		if (p->rules[i].default_action == IPE_ACTION_INVALID)
+			return -EBADMSG;
+	}
+
+	return 0;
+}
+
+/**
+ * ipe_parse_policy() - Given a string, parse the string into an IPE policy.
+ * @p: partially filled ipe_policy structure to populate with the result.
+ *     it must have text and textlen set.
+ *
+ * Return:
+ * * %0		- Success
+ * * %-EBADMSG	- Policy is invalid
+ * * %-ENOMEM	- Out of Memory
+ * * %-ERANGE	- Policy version number overflow
+ * * %-EINVAL	- Policy version parsing error
+ */
+int ipe_parse_policy(struct ipe_policy *p)
+{
+	struct ipe_parsed_policy *pp = NULL;
+	char *policy = NULL, *dup = NULL;
+	bool header_parsed = false;
+	char *line = NULL;
+	size_t len;
+	int rc = 0;
+
+	if (!p->textlen)
+		return -EBADMSG;
+
+	policy = kmemdup_nul(p->text, p->textlen, GFP_KERNEL);
+	if (!policy)
+		return -ENOMEM;
+	dup = policy;
+
+	pp = new_parsed_policy();
+	if (IS_ERR(pp)) {
+		rc = PTR_ERR(pp);
+		goto out;
+	}
+
+	while ((line = strsep(&policy, IPE_LINE_DELIM)) != NULL) {
+		remove_comment(line);
+		len = remove_trailing_spaces(line);
+		if (!len)
+			continue;
+
+		if (!header_parsed) {
+			rc = parse_header(line, pp);
+			if (rc)
+				goto err;
+			header_parsed = true;
+		} else {
+			rc = parse_rule(line, pp);
+			if (rc)
+				goto err;
+		}
+	}
+
+	if (!header_parsed || validate_policy(pp)) {
+		rc = -EBADMSG;
+		goto err;
+	}
+
+	p->parsed = pp;
+
+out:
+	kfree(dup);
+	return rc;
+err:
+	ipe_free_parsed_policy(pp);
+	goto out;
+}