Merge tag 'integrity-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

Pull integrity subsystem updates from Mimi Zohar:
 "Other than the new gid IMA policy rule support and the RCU locking
  fix, the couple of remaining changes are minor/trivial (e.g.
  __ro_after_init, replacing strscpy)"

* tag 'integrity-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  evm: mark evm_fixmode as __ro_after_init
  ima: Use strscpy instead of strlcpy
  ima_policy: Remove duplicate 'the' in docs comment
  ima: add gid support
  ima: fix uid code style problems
  ima: fix deadlock when traversing "ima_default_rules".

3 files changed, 202 insertions, 45 deletions

diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index 1c8435dfabee..08f907382c61 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -78,7 +78,7 @@ static struct xattr_list evm_config_default_xattrnames[] = {
 
 LIST_HEAD(evm_config_xattrnames);
 
-static int evm_fixmode;
+static int evm_fixmode __ro_after_init;
 static int __init evm_set_fixmode(char *str)
 {
 	if (strncmp(str, "fix", 3) == 0)
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 2c6c3a5228b5..a64fb0130b01 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -403,7 +403,7 @@ const char *ima_d_path(const struct path *path, char **pathbuf, char *namebuf)
 	}
 
 	if (!pathname) {
-		strlcpy(namebuf, path->dentry->d_name.name, NAME_MAX);
+		strscpy(namebuf, path->dentry->d_name.name, NAME_MAX);
 		pathname = namebuf;
 	}
 
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 87b9b71cb820..320ca80aacab 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -36,6 +36,9 @@
 #define IMA_KEYRINGS	0x0400
 #define IMA_LABEL	0x0800
 #define IMA_VALIDATE_ALGOS	0x1000
+#define IMA_GID		0x2000
+#define IMA_EGID	0x4000
+#define IMA_FGROUP	0x8000
 
 #define UNKNOWN		0
 #define MEASURE		0x0001	/* same as IMA_MEASURE */
@@ -78,9 +81,13 @@ struct ima_rule_entry {
 	unsigned long fsmagic;
 	uuid_t fsuuid;
 	kuid_t uid;
+	kgid_t gid;
 	kuid_t fowner;
-	bool (*uid_op)(kuid_t, kuid_t);    /* Handlers for operators       */
-	bool (*fowner_op)(kuid_t, kuid_t); /* uid_eq(), uid_gt(), uid_lt() */
+	kgid_t fgroup;
+	bool (*uid_op)(kuid_t cred_uid, kuid_t rule_uid);    /* Handlers for operators       */
+	bool (*gid_op)(kgid_t cred_gid, kgid_t rule_gid);
+	bool (*fowner_op)(kuid_t cred_uid, kuid_t rule_uid); /* uid_eq(), uid_gt(), uid_lt() */
+	bool (*fgroup_op)(kgid_t cred_gid, kgid_t rule_gid); /* gid_eq(), gid_gt(), gid_lt() */
 	int pcr;
 	unsigned int allowed_algos; /* bitfield of allowed hash algorithms */
 	struct {
@@ -104,7 +111,8 @@ static_assert(
 
 /*
  * Without LSM specific knowledge, the default policy can only be
- * written in terms of .action, .func, .mask, .fsmagic, .uid, and .fowner
+ * written in terms of .action, .func, .mask, .fsmagic, .uid, .gid,
+ * .fowner, and .fgroup
  */
 
 /*
@@ -228,7 +236,7 @@ static struct ima_rule_entry *arch_policy_entry __ro_after_init;
 static LIST_HEAD(ima_default_rules);
 static LIST_HEAD(ima_policy_rules);
 static LIST_HEAD(ima_temp_rules);
-static struct list_head *ima_rules = &ima_default_rules;
+static struct list_head __rcu *ima_rules = (struct list_head __rcu *)(&ima_default_rules);
 
 static int ima_policy __initdata;
 
@@ -582,10 +590,23 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
 		} else if (!rule->uid_op(cred->euid, rule->uid))
 			return false;
 	}
-
+	if ((rule->flags & IMA_GID) && !rule->gid_op(cred->gid, rule->gid))
+		return false;
+	if (rule->flags & IMA_EGID) {
+		if (has_capability_noaudit(current, CAP_SETGID)) {
+			if (!rule->gid_op(cred->egid, rule->gid)
+			    && !rule->gid_op(cred->sgid, rule->gid)
+			    && !rule->gid_op(cred->gid, rule->gid))
+				return false;
+		} else if (!rule->gid_op(cred->egid, rule->gid))
+			return false;
+	}
 	if ((rule->flags & IMA_FOWNER) &&
 	    !rule->fowner_op(i_uid_into_mnt(mnt_userns, inode), rule->fowner))
 		return false;
+	if ((rule->flags & IMA_FGROUP) &&
+	    !rule->fgroup_op(i_gid_into_mnt(mnt_userns, inode), rule->fgroup))
+		return false;
 	for (i = 0; i < MAX_LSM_RULES; i++) {
 		int rc = 0;
 		u32 osid;
@@ -675,12 +696,14 @@ int ima_match_policy(struct user_namespace *mnt_userns, struct inode *inode,
 {
 	struct ima_rule_entry *entry;
 	int action = 0, actmask = flags | (flags << 1);
+	struct list_head *ima_rules_tmp;
 
 	if (template_desc && !*template_desc)
 		*template_desc = ima_template_desc_current();
 
 	rcu_read_lock();
-	list_for_each_entry_rcu(entry, ima_rules, list) {
+	ima_rules_tmp = rcu_dereference(ima_rules);
+	list_for_each_entry_rcu(entry, ima_rules_tmp, list) {
 
 		if (!(entry->action & actmask))
 			continue;
@@ -741,9 +764,11 @@ void ima_update_policy_flags(void)
 {
 	struct ima_rule_entry *entry;
 	int new_policy_flag = 0;
+	struct list_head *ima_rules_tmp;
 
 	rcu_read_lock();
-	list_for_each_entry(entry, ima_rules, list) {
+	ima_rules_tmp = rcu_dereference(ima_rules);
+	list_for_each_entry_rcu(entry, ima_rules_tmp, list) {
 		/*
 		 * SETXATTR_CHECK rules do not implement a full policy check
 		 * because rule checking would probably have an important
@@ -845,7 +870,7 @@ static int __init ima_init_arch_policy(void)
 		char rule[255];
 		int result;
 
-		result = strlcpy(rule, *rules, sizeof(rule));
+		result = strscpy(rule, *rules, sizeof(rule));
 
 		INIT_LIST_HEAD(&arch_policy_entry[i].list);
 		result = ima_parse_rule(rule, &arch_policy_entry[i]);
@@ -864,8 +889,7 @@ static int __init ima_init_arch_policy(void)
 /**
  * ima_init_policy - initialize the default measure rules.
  *
- * ima_rules points to either the ima_default_rules or the
- * the new ima_policy_rules.
+ * ima_rules points to either the ima_default_rules or the new ima_policy_rules.
  */
 void __init ima_init_policy(void)
 {
@@ -968,10 +992,10 @@ void ima_update_policy(void)
 
 	list_splice_tail_init_rcu(&ima_temp_rules, policy, synchronize_rcu);
 
-	if (ima_rules != policy) {
+	if (ima_rules != (struct list_head __rcu *)policy) {
 		ima_policy_flag = 0;
-		ima_rules = policy;
 
+		rcu_assign_pointer(ima_rules, policy);
 		/*
 		 * IMA architecture specific policy rules are specified
 		 * as strings and converted to an array of ima_entry_rules
@@ -987,16 +1011,19 @@ void ima_update_policy(void)
 }
 
 /* Keep the enumeration in sync with the policy_tokens! */
-enum {
+enum policy_opt {
 	Opt_measure, Opt_dont_measure,
 	Opt_appraise, Opt_dont_appraise,
 	Opt_audit, Opt_hash, Opt_dont_hash,
 	Opt_obj_user, Opt_obj_role, Opt_obj_type,
 	Opt_subj_user, Opt_subj_role, Opt_subj_type,
-	Opt_func, Opt_mask, Opt_fsmagic, Opt_fsname,
-	Opt_fsuuid, Opt_uid_eq, Opt_euid_eq, Opt_fowner_eq,
-	Opt_uid_gt, Opt_euid_gt, Opt_fowner_gt,
-	Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt,
+	Opt_func, Opt_mask, Opt_fsmagic, Opt_fsname, Opt_fsuuid,
+	Opt_uid_eq, Opt_euid_eq, Opt_gid_eq, Opt_egid_eq,
+	Opt_fowner_eq, Opt_fgroup_eq,
+	Opt_uid_gt, Opt_euid_gt, Opt_gid_gt, Opt_egid_gt,
+	Opt_fowner_gt, Opt_fgroup_gt,
+	Opt_uid_lt, Opt_euid_lt, Opt_gid_lt, Opt_egid_lt,
+	Opt_fowner_lt, Opt_fgroup_lt,
 	Opt_appraise_type, Opt_appraise_flag, Opt_appraise_algos,
 	Opt_permit_directio, Opt_pcr, Opt_template, Opt_keyrings,
 	Opt_label, Opt_err
@@ -1023,13 +1050,22 @@ static const match_table_t policy_tokens = {
 	{Opt_fsuuid, "fsuuid=%s"},
 	{Opt_uid_eq, "uid=%s"},
 	{Opt_euid_eq, "euid=%s"},
+	{Opt_gid_eq, "gid=%s"},
+	{Opt_egid_eq, "egid=%s"},
 	{Opt_fowner_eq, "fowner=%s"},
+	{Opt_fgroup_eq, "fgroup=%s"},
 	{Opt_uid_gt, "uid>%s"},
 	{Opt_euid_gt, "euid>%s"},
+	{Opt_gid_gt, "gid>%s"},
+	{Opt_egid_gt, "egid>%s"},
 	{Opt_fowner_gt, "fowner>%s"},
+	{Opt_fgroup_gt, "fgroup>%s"},
 	{Opt_uid_lt, "uid<%s"},
 	{Opt_euid_lt, "euid<%s"},
+	{Opt_gid_lt, "gid<%s"},
+	{Opt_egid_lt, "egid<%s"},
 	{Opt_fowner_lt, "fowner<%s"},
+	{Opt_fgroup_lt, "fgroup<%s"},
 	{Opt_appraise_type, "appraise_type=%s"},
 	{Opt_appraise_flag, "appraise_flag=%s"},
 	{Opt_appraise_algos, "appraise_algos=%s"},
@@ -1061,7 +1097,7 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry,
 		pr_warn("rule for LSM \'%s\' is undefined\n",
 			entry->lsm[lsm_rule].args_p);
 
-		if (ima_rules == &ima_default_rules) {
+		if (ima_rules == (struct list_head __rcu *)(&ima_default_rules)) {
 			kfree(entry->lsm[lsm_rule].args_p);
 			entry->lsm[lsm_rule].args_p = NULL;
 			result = -EINVAL;
@@ -1073,22 +1109,36 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry,
 }
 
 static void ima_log_string_op(struct audit_buffer *ab, char *key, char *value,
-			      bool (*rule_operator)(kuid_t, kuid_t))
+			      enum policy_opt rule_operator)
 {
 	if (!ab)
 		return;
 
-	if (rule_operator == &uid_gt)
+	switch (rule_operator) {
+	case Opt_uid_gt:
+	case Opt_euid_gt:
+	case Opt_gid_gt:
+	case Opt_egid_gt:
+	case Opt_fowner_gt:
+	case Opt_fgroup_gt:
 		audit_log_format(ab, "%s>", key);
-	else if (rule_operator == &uid_lt)
+		break;
+	case Opt_uid_lt:
+	case Opt_euid_lt:
+	case Opt_gid_lt:
+	case Opt_egid_lt:
+	case Opt_fowner_lt:
+	case Opt_fgroup_lt:
 		audit_log_format(ab, "%s<", key);
-	else
+		break;
+	default:
 		audit_log_format(ab, "%s=", key);
+	}
 	audit_log_format(ab, "%s ", value);
 }
 static void ima_log_string(struct audit_buffer *ab, char *key, char *value)
 {
-	ima_log_string_op(ab, key, value, NULL);
+	ima_log_string_op(ab, key, value, Opt_err);
 }
 
 /*
@@ -1163,7 +1213,8 @@ static bool ima_validate_rule(struct ima_rule_entry *entry)
 		if (entry->flags & ~(IMA_FUNC | IMA_MASK | IMA_FSMAGIC |
 				     IMA_UID | IMA_FOWNER | IMA_FSUUID |
 				     IMA_INMASK | IMA_EUID | IMA_PCR |
-				     IMA_FSNAME | IMA_DIGSIG_REQUIRED |
+				     IMA_FSNAME | IMA_GID | IMA_EGID |
+				     IMA_FGROUP | IMA_DIGSIG_REQUIRED |
 				     IMA_PERMIT_DIRECTIO | IMA_VALIDATE_ALGOS))
 			return false;
 
@@ -1174,7 +1225,8 @@ static bool ima_validate_rule(struct ima_rule_entry *entry)
 		if (entry->flags & ~(IMA_FUNC | IMA_MASK | IMA_FSMAGIC |
 				     IMA_UID | IMA_FOWNER | IMA_FSUUID |
 				     IMA_INMASK | IMA_EUID | IMA_PCR |
-				     IMA_FSNAME | IMA_DIGSIG_REQUIRED |
+				     IMA_FSNAME | IMA_GID | IMA_EGID |
+				     IMA_FGROUP | IMA_DIGSIG_REQUIRED |
 				     IMA_PERMIT_DIRECTIO | IMA_MODSIG_ALLOWED |
 				     IMA_CHECK_BLACKLIST | IMA_VALIDATE_ALGOS))
 			return false;
@@ -1186,7 +1238,8 @@ static bool ima_validate_rule(struct ima_rule_entry *entry)
 
 		if (entry->flags & ~(IMA_FUNC | IMA_FSMAGIC | IMA_UID |
 				     IMA_FOWNER | IMA_FSUUID | IMA_EUID |
-				     IMA_PCR | IMA_FSNAME))
+				     IMA_PCR | IMA_FSNAME | IMA_GID | IMA_EGID |
+				     IMA_FGROUP))
 			return false;
 
 		break;
@@ -1194,7 +1247,7 @@ static bool ima_validate_rule(struct ima_rule_entry *entry)
 		if (entry->action & ~(MEASURE | DONT_MEASURE))
 			return false;
 
-		if (entry->flags & ~(IMA_FUNC | IMA_UID | IMA_PCR |
+		if (entry->flags & ~(IMA_FUNC | IMA_UID | IMA_GID | IMA_PCR |
 				     IMA_KEYRINGS))
 			return false;
 
@@ -1206,7 +1259,7 @@ static bool ima_validate_rule(struct ima_rule_entry *entry)
 		if (entry->action & ~(MEASURE | DONT_MEASURE))
 			return false;
 
-		if (entry->flags & ~(IMA_FUNC | IMA_UID | IMA_PCR |
+		if (entry->flags & ~(IMA_FUNC | IMA_UID | IMA_GID | IMA_PCR |
 				     IMA_LABEL))
 			return false;
 
@@ -1276,7 +1329,7 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 	struct audit_buffer *ab;
 	char *from;
 	char *p;
-	bool uid_token;
+	bool eid_token; /* either euid or egid */
 	struct ima_template_desc *template_desc;
 	int result = 0;
 
@@ -1284,9 +1337,13 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 				       AUDIT_INTEGRITY_POLICY_RULE);
 
 	entry->uid = INVALID_UID;
+	entry->gid = INVALID_GID;
 	entry->fowner = INVALID_UID;
+	entry->fgroup = INVALID_GID;
 	entry->uid_op = &uid_eq;
+	entry->gid_op = &gid_eq;
 	entry->fowner_op = &uid_eq;
+	entry->fgroup_op = &gid_eq;
 	entry->action = UNKNOWN;
 	while ((p = strsep(&rule, " \t")) != NULL) {
 		substring_t args[MAX_OPT_ARGS];
@@ -1504,12 +1561,12 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 			fallthrough;
 		case Opt_uid_eq:
 		case Opt_euid_eq:
-			uid_token = (token == Opt_uid_eq) ||
-				    (token == Opt_uid_gt) ||
-				    (token == Opt_uid_lt);
+			eid_token = (token == Opt_euid_eq) ||
+				    (token == Opt_euid_gt) ||
+				    (token == Opt_euid_lt);
 
-			ima_log_string_op(ab, uid_token ? "uid" : "euid",
-					  args[0].from, entry->uid_op);
+			ima_log_string_op(ab, eid_token ? "euid" : "uid",
+					  args[0].from, token);
 
 			if (uid_valid(entry->uid)) {
 				result = -EINVAL;
@@ -1524,8 +1581,43 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 				    (uid_t)lnum != lnum)
 					result = -EINVAL;
 				else
-					entry->flags |= uid_token
-					    ? IMA_UID : IMA_EUID;
+					entry->flags |= eid_token
+					    ? IMA_EUID : IMA_UID;
+			}
+			break;
+		case Opt_gid_gt:
+		case Opt_egid_gt:
+			entry->gid_op = &gid_gt;
+			fallthrough;
+		case Opt_gid_lt:
+		case Opt_egid_lt:
+			if ((token == Opt_gid_lt) || (token == Opt_egid_lt))
+				entry->gid_op = &gid_lt;
+			fallthrough;
+		case Opt_gid_eq:
+		case Opt_egid_eq:
+			eid_token = (token == Opt_egid_eq) ||
+				    (token == Opt_egid_gt) ||
+				    (token == Opt_egid_lt);
+
+			ima_log_string_op(ab, eid_token ? "egid" : "gid",
+					  args[0].from, token);
+
+			if (gid_valid(entry->gid)) {
+				result = -EINVAL;
+				break;
+			}
+
+			result = kstrtoul(args[0].from, 10, &lnum);
+			if (!result) {
+				entry->gid = make_kgid(current_user_ns(),
+						       (gid_t)lnum);
+				if (!gid_valid(entry->gid) ||
+				    (((gid_t)lnum) != lnum))
+					result = -EINVAL;
+				else
+					entry->flags |= eid_token
+					    ? IMA_EGID : IMA_GID;
 			}
 			break;
 		case Opt_fowner_gt:
@@ -1536,8 +1628,7 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 				entry->fowner_op = &uid_lt;
 			fallthrough;
 		case Opt_fowner_eq:
-			ima_log_string_op(ab, "fowner", args[0].from,
-					  entry->fowner_op);
+			ima_log_string_op(ab, "fowner", args[0].from, token);
 
 			if (uid_valid(entry->fowner)) {
 				result = -EINVAL;
@@ -1546,13 +1637,41 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 
 			result = kstrtoul(args[0].from, 10, &lnum);
 			if (!result) {
-				entry->fowner = make_kuid(current_user_ns(), (uid_t)lnum);
-				if (!uid_valid(entry->fowner) || (((uid_t)lnum) != lnum))
+				entry->fowner = make_kuid(current_user_ns(),
+							  (uid_t)lnum);
+				if (!uid_valid(entry->fowner) ||
+				    (((uid_t)lnum) != lnum))
 					result = -EINVAL;
 				else
 					entry->flags |= IMA_FOWNER;
 			}
 			break;
+		case Opt_fgroup_gt:
+			entry->fgroup_op = &gid_gt;
+			fallthrough;
+		case Opt_fgroup_lt:
+			if (token == Opt_fgroup_lt)
+				entry->fgroup_op = &gid_lt;
+			fallthrough;
+		case Opt_fgroup_eq:
+			ima_log_string_op(ab, "fgroup", args[0].from, token);
+
+			if (gid_valid(entry->fgroup)) {
+				result = -EINVAL;
+				break;
+			}
+
+			result = kstrtoul(args[0].from, 10, &lnum);
+			if (!result) {
+				entry->fgroup = make_kgid(current_user_ns(),
+							  (gid_t)lnum);
+				if (!gid_valid(entry->fgroup) ||
+				    (((gid_t)lnum) != lnum))
+					result = -EINVAL;
+				else
+					entry->flags |= IMA_FGROUP;
+			}
+			break;
 		case Opt_obj_user:
 			ima_log_string(ab, "obj_user", args[0].from);
 			result = ima_lsm_rule_init(entry, args,
@@ -1768,9 +1887,11 @@ void *ima_policy_start(struct seq_file *m, loff_t *pos)
 {
 	loff_t l = *pos;
 	struct ima_rule_entry *entry;
+	struct list_head *ima_rules_tmp;
 
 	rcu_read_lock();
-	list_for_each_entry_rcu(entry, ima_rules, list) {
+	ima_rules_tmp = rcu_dereference(ima_rules);
+	list_for_each_entry_rcu(entry, ima_rules_tmp, list) {
 		if (!l--) {
 			rcu_read_unlock();
 			return entry;
@@ -1789,7 +1910,8 @@ void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos)
 	rcu_read_unlock();
 	(*pos)++;
 
-	return (&entry->list == ima_rules) ? NULL : entry;
+	return (&entry->list == &ima_default_rules ||
+		&entry->list == &ima_policy_rules) ? NULL : entry;
 }
 
 void ima_policy_stop(struct seq_file *m, void *v)
@@ -1936,6 +2058,28 @@ int ima_policy_show(struct seq_file *m, void *v)
 		seq_puts(m, " ");
 	}
 
+	if (entry->flags & IMA_GID) {
+		snprintf(tbuf, sizeof(tbuf), "%d", __kgid_val(entry->gid));
+		if (entry->gid_op == &gid_gt)
+			seq_printf(m, pt(Opt_gid_gt), tbuf);
+		else if (entry->gid_op == &gid_lt)
+			seq_printf(m, pt(Opt_gid_lt), tbuf);
+		else
+			seq_printf(m, pt(Opt_gid_eq), tbuf);
+		seq_puts(m, " ");
+	}
+
+	if (entry->flags & IMA_EGID) {
+		snprintf(tbuf, sizeof(tbuf), "%d", __kgid_val(entry->gid));
+		if (entry->gid_op == &gid_gt)
+			seq_printf(m, pt(Opt_egid_gt), tbuf);
+		else if (entry->gid_op == &gid_lt)
+			seq_printf(m, pt(Opt_egid_lt), tbuf);
+		else
+			seq_printf(m, pt(Opt_egid_eq), tbuf);
+		seq_puts(m, " ");
+	}
+
 	if (entry->flags & IMA_FOWNER) {
 		snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->fowner));
 		if (entry->fowner_op == &uid_gt)
@@ -1947,6 +2091,17 @@ int ima_policy_show(struct seq_file *m, void *v)
 		seq_puts(m, " ");
 	}
 
+	if (entry->flags & IMA_FGROUP) {
+		snprintf(tbuf, sizeof(tbuf), "%d", __kgid_val(entry->fgroup));
+		if (entry->fgroup_op == &gid_gt)
+			seq_printf(m, pt(Opt_fgroup_gt), tbuf);
+		else if (entry->fgroup_op == &gid_lt)
+			seq_printf(m, pt(Opt_fgroup_lt), tbuf);
+		else
+			seq_printf(m, pt(Opt_fgroup_eq), tbuf);
+		seq_puts(m, " ");
+	}
+
 	if (entry->flags & IMA_VALIDATE_ALGOS) {
 		seq_puts(m, "appraise_algos=");
 		ima_policy_show_appraise_algos(m, entry->allowed_algos);
@@ -2014,6 +2169,7 @@ bool ima_appraise_signature(enum kernel_read_file_id id)
 	struct ima_rule_entry *entry;
 	bool found = false;
 	enum ima_hooks func;
+	struct list_head *ima_rules_tmp;
 
 	if (id >= READING_MAX_ID)
 		return false;
@@ -2021,7 +2177,8 @@ bool ima_appraise_signature(enum kernel_read_file_id id)
 	func = read_idmap[id] ?: FILE_CHECK;
 
 	rcu_read_lock();
-	list_for_each_entry_rcu(entry, ima_rules, list) {
+	ima_rules_tmp = rcu_dereference(ima_rules);
+	list_for_each_entry_rcu(entry, ima_rules_tmp, list) {
 		if (entry->action != APPRAISE)
 			continue;